first commit

application/controllers/About.php

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+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * About controller.
+ *
+ * Handles about settings related operations.
+ *
+ * @package Controllers
+ */
+class About extends EA_Controller
+{
+    /**
+     * About constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('appointments_model');
+        $this->load->model('customers_model');
+        $this->load->model('services_model');
+        $this->load->model('providers_model');
+        $this->load->model('roles_model');
+        $this->load->model('settings_model');
+
+        $this->load->library('accounts');
+        $this->load->library('google_sync');
+        $this->load->library('notifications');
+        $this->load->library('synchronization');
+        $this->load->library('timezones');
+    }
+
+    /**
+     * Render the settings page.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('about')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_USER_SETTINGS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+        ]);
+
+        html_vars([
+            'page_title' => lang('settings'),
+            'active_menu' => PRIV_SYSTEM_SETTINGS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+            'privileges' => $this->roles_model->get_permissions_by_slug($role_slug),
+        ]);
+
+        $this->load->view('pages/about');
+    }
+}

application/controllers/Account.php

@@ -0,0 +1,166 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Account controller.
+ *
+ * Handles current account related operations.
+ *
+ * @package Controllers
+ */
+class Account extends EA_Controller
+{
+    public array $allowed_user_fields = [
+        'id',
+        'first_name',
+        'last_name',
+        'email',
+        'mobile_number',
+        'phone_number',
+        'address',
+        'city',
+        'state',
+        'zip_code',
+        'notes',
+        'timezone',
+        'language',
+        'settings',
+    ];
+
+    public array $optional_user_fields = [
+        //
+    ];
+
+    public array $allowed_user_setting_fields = ['username', 'password', 'notifications', 'calendar_view'];
+
+    public array $optional_user_setting_fields = [
+        //
+    ];
+
+    /**
+     * Account constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('appointments_model');
+        $this->load->model('customers_model');
+        $this->load->model('services_model');
+        $this->load->model('providers_model');
+        $this->load->model('roles_model');
+        $this->load->model('settings_model');
+
+        $this->load->library('accounts');
+        $this->load->library('google_sync');
+        $this->load->library('notifications');
+        $this->load->library('synchronization');
+        $this->load->library('timezones');
+    }
+
+    /**
+     * Render the settings page.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('account')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_USER_SETTINGS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $account = $this->users_model->find($user_id);
+
+        script_vars([
+            'account' => $account,
+        ]);
+
+        html_vars([
+            'page_title' => lang('settings'),
+            'active_menu' => PRIV_SYSTEM_SETTINGS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+            'grouped_timezones' => $this->timezones->to_grouped_array(),
+        ]);
+
+        $this->load->view('pages/account');
+    }
+
+    /**
+     * Save general settings.
+     */
+    public function save(): void
+    {
+        try {
+            if (cannot('edit', PRIV_USER_SETTINGS)) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $account = request('account');
+
+            $account['id'] = session('user_id');
+
+            $this->users_model->only($account, $this->allowed_user_fields);
+
+            $this->users_model->optional($account, $this->optional_user_fields);
+
+            $this->users_model->only($account['settings'], $this->allowed_user_setting_fields);
+
+            $this->users_model->optional($account['settings'], $this->optional_user_setting_fields);
+
+            if (empty($account['password'])) {
+                unset($account['password']);
+            }
+
+            $this->users_model->save($account);
+
+            session([
+                'user_email' => $account['email'],
+                'username' => $account['settings']['username'],
+                'timezone' => $account['timezone'],
+                'language' => $account['language'],
+            ]);
+
+            response();
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Make sure the username is valid and unique in the database.
+     */
+    public function validate_username(): void
+    {
+        try {
+            $username = request('username');
+
+            $user_id = request('user_id');
+
+            $is_valid = $this->users_model->validate_username($username, $user_id);
+
+            json_response([
+                'is_valid' => $is_valid,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Admins.php

@@ -0,0 +1,247 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Admins controller.
+ *
+ * Handles the admins related operations.
+ *
+ * @package Controllers
+ */
+class Admins extends EA_Controller
+{
+    public array $allowed_admin_fields = [
+        'id',
+        'first_name',
+        'last_name',
+        'email',
+        'mobile_number',
+        'phone_number',
+        'address',
+        'city',
+        'state',
+        'zip_code',
+        'notes',
+        'timezone',
+        'language',
+        'ldap_dn',
+        'settings',
+    ];
+
+    public array $optional_admin_fields = [
+        //
+    ];
+
+    public array $allowed_admin_setting_fields = ['username', 'password', 'notifications', 'calendar_view'];
+
+    public array $optional_admin_setting_fields = [
+        //
+    ];
+
+    /**
+     * Admins constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('admins_model');
+        $this->load->model('roles_model');
+
+        $this->load->library('accounts');
+        $this->load->library('timezones');
+        $this->load->library('webhooks_client');
+    }
+
+    /**
+     * Render the backend admins page.
+     *
+     * On this page admin users will be able to manage admins, which are eventually selected by customers during the
+     * booking process.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('admins')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_USERS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'timezones' => $this->timezones->to_array(),
+            'min_password_length' => MIN_PASSWORD_LENGTH,
+            'default_language' => setting('default_language'),
+            'default_timezone' => setting('default_timezone'),
+        ]);
+
+        html_vars([
+            'page_title' => lang('admins'),
+            'active_menu' => PRIV_USERS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+            'grouped_timezones' => $this->timezones->to_grouped_array(),
+            'privileges' => $this->roles_model->get_permissions_by_slug($role_slug),
+        ]);
+
+        $this->load->view('pages/admins');
+    }
+
+    /**
+     * Filter admins by the provided keyword.
+     */
+    public function search(): void
+    {
+        try {
+            if (cannot('view', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $keyword = request('keyword', '');
+
+            $order_by = request('order_by', 'update_datetime DESC');
+
+            $limit = request('limit', 1000);
+
+            $offset = (int) request('offset', '0');
+
+            $admins = $this->admins_model->search($keyword, $limit, $offset, $order_by);
+
+            json_response($admins);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new admin.
+     */
+    public function store(): void
+    {
+        try {
+            if (cannot('add', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $admin = request('admin');
+
+            $this->admins_model->only($admin, $this->allowed_admin_fields);
+
+            $this->admins_model->optional($admin, $this->optional_admin_fields);
+
+            $this->admins_model->only($admin['settings'], $this->allowed_admin_setting_fields);
+
+            $this->admins_model->optional($admin['settings'], $this->optional_admin_setting_fields);
+
+            $admin_id = $this->admins_model->save($admin);
+
+            $admin = $this->admins_model->find($admin_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_ADMIN_SAVE, $admin);
+
+            json_response([
+                'success' => true,
+                'id' => $admin_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Find an admin.
+     */
+    public function find(): void
+    {
+        try {
+            if (cannot('view', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $admin_id = request('admin_id');
+
+            $admin = $this->admins_model->find($admin_id);
+
+            json_response($admin);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update an admin.
+     */
+    public function update(): void
+    {
+        try {
+            if (cannot('edit', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $admin = request('admin');
+
+            $this->admins_model->only($admin, $this->allowed_admin_fields);
+
+            $this->admins_model->only($admin['settings'], $this->allowed_admin_setting_fields);
+
+            $admin_id = $this->admins_model->save($admin);
+
+            $admin = $this->admins_model->find($admin_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_ADMIN_SAVE, $admin);
+
+            json_response([
+                'success' => true,
+                'id' => $admin_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Remove an admin.
+     */
+    public function destroy(): void
+    {
+        try {
+            if (cannot('delete', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $admin_id = request('admin_id');
+
+            $admin = $this->admins_model->find($admin_id);
+
+            $this->admins_model->delete($admin_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_ADMIN_DELETE, $admin);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Api_settings.php

@@ -0,0 +1,102 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * API settings controller.
+ *
+ * Handles API settings related operations.
+ *
+ * @package Controllers
+ */
+class Api_settings extends EA_Controller
+{
+    /**
+     * Api_settings constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('settings_model');
+
+        $this->load->library('accounts');
+    }
+
+    /**
+     * Render the settings page.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('api_settings')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_SYSTEM_SETTINGS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'api_settings' => $this->settings_model->get('name like "api_%"'),
+        ]);
+
+        html_vars([
+            'page_title' => lang('api'),
+            'active_menu' => PRIV_SYSTEM_SETTINGS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+        ]);
+
+        $this->load->view('pages/api_settings');
+    }
+
+    /**
+     * Save general settings.
+     */
+    public function save(): void
+    {
+        try {
+            if (cannot('edit', PRIV_SYSTEM_SETTINGS)) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $settings = request('api_settings', []);
+
+            foreach ($settings as $setting) {
+                $existing_setting = $this->settings_model
+                    ->query()
+                    ->where('name', $setting['name'])
+                    ->get()
+                    ->row_array();
+
+                if (!empty($existing_setting)) {
+                    $setting['id'] = $existing_setting['id'];
+                }
+
+                $this->settings_model->save($setting);
+            }
+
+            response();
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Appointments.php

@@ -0,0 +1,200 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Appointments controller.
+ *
+ * Handles the appointments related operations.
+ *
+ * Notice: This file used to have the booking page related code which since v1.5 has now moved to the Booking.php
+ * controller for improved consistency.
+ *
+ * @package Controllers
+ */
+class Appointments extends EA_Controller
+{
+    public array $allowed_appointment_fields = [
+        'id',
+        'start_datetime',
+        'end_datetime',
+        'location',
+        'notes',
+        'color',
+        'status',
+        'is_unavailability',
+        'id_users_provider',
+        'id_users_customer',
+        'id_services',
+    ];
+
+    public array $optional_appointment_fields = [
+        //
+    ];
+
+    /**
+     * Appointments constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('appointments_model');
+        $this->load->model('roles_model');
+
+        $this->load->library('accounts');
+        $this->load->library('timezones');
+        $this->load->library('webhooks_client');
+    }
+
+    /**
+     * Support backwards compatibility for appointment links that still point to this URL.
+     *
+     * @param string $appointment_hash
+     *
+     * @deprecated Since 1.5
+     */
+    public function index(string $appointment_hash = ''): void
+    {
+        redirect('booking/' . $appointment_hash);
+    }
+
+    /**
+     * Filter appointments by the provided keyword.
+     */
+    public function search(): void
+    {
+        try {
+            if (cannot('view', PRIV_APPOINTMENTS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $keyword = request('keyword', '');
+
+            $order_by = request('order_by', 'update_datetime DESC');
+
+            $limit = request('limit', 1000);
+
+            $offset = (int) request('offset', '0');
+
+            $appointments = $this->appointments_model->search($keyword, $limit, $offset, $order_by);
+
+            json_response($appointments);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new appointment.
+     */
+    public function store(): void
+    {
+        try {
+            if (cannot('add', PRIV_APPOINTMENTS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $appointment = json_decode(request('appointment'), true);
+
+            $this->appointments_model->only($appointment, $this->allowed_appointment_fields);
+
+            $this->appointments_model->optional($appointment, $this->optional_appointment_fields);
+
+            $appointment_id = $this->appointments_model->save($appointment);
+
+            $appointment = $this->appointments_model->find($appointment);
+
+            $this->webhooks_client->trigger(WEBHOOK_APPOINTMENT_SAVE, $appointment);
+
+            json_response([
+                'success' => true,
+                'id' => $appointment_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Find an appointment.
+     */
+    public function find(): void
+    {
+        try {
+            if (cannot('view', PRIV_APPOINTMENTS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $appointment_id = request('appointment_id');
+
+            $appointment = $this->appointments_model->find($appointment_id);
+
+            json_response($appointment);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a appointment.
+     */
+    public function update(): void
+    {
+        try {
+            if (cannot('edit', PRIV_APPOINTMENTS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $appointment = json_decode(request('appointment'), true);
+
+            $this->appointments_model->only($appointment, $this->allowed_appointment_fields);
+
+            $this->appointments_model->optional($appointment, $this->optional_appointment_fields);
+
+            $appointment_id = $this->appointments_model->save($appointment);
+
+            json_response([
+                'success' => true,
+                'id' => $appointment_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Remove a appointment.
+     */
+    public function destroy(): void
+    {
+        try {
+            if (cannot('delete', PRIV_APPOINTMENTS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $appointment_id = request('appointment_id');
+
+            $appointment = $this->appointments_model->find($appointment_id);
+
+            $this->appointments_model->delete($appointment_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_APPOINTMENT_DELETE, $appointment);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Backend.php

@@ -0,0 +1,103 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/*
+|------------------------------------------------------------------------------
+| Deprecation Notice
+|------------------------------------------------------------------------------
+|
+| This file is still in the project for backwards compatibility reasons and for 
+| providing additional information on how to migrate your code to the latest   
+| codebase state. 
+|
+| Visit the Easy!Appointments Developers website for more information:  
+|
+|   https://developers.easyappointments.org
+|
+| Since v1.5, the methods of this controller were ported to standalone controller 
+| classes, that can both handle the page rendering and all asynchronous HTTP  
+| requests. 
+|
+*/
+
+/**
+ * Backend controller.
+ *
+ * Handles the backend related operations.
+ *
+ * @package Controllers
+ *
+ * @deprecated Since 1.5
+ */
+class Backend extends EA_Controller
+{
+    /**
+     * Display the calendar page.
+     *
+     * @param string $appointment_hash Appointment edit dialog will appear when the page loads (default '').
+     */
+    public function index(string $appointment_hash = ''): void
+    {
+        if (empty($appointment_hash)) {
+            redirect('calendar');
+        } else {
+            redirect('calendar/reschedule/' . $appointment_hash);
+        }
+    }
+
+    /**
+     * Display the customers page.
+     */
+    public function customers(): void
+    {
+        redirect('customers');
+    }
+
+    /**
+     * Display the services page.
+     */
+    public function services(): void
+    {
+        redirect('services');
+    }
+
+    /**
+     * Display the users page.
+     *
+     * Notice: Since the "users" page is split into multiple pages (providers, secretaries, admins), this method will
+     * redirect to "providers" page by default
+     */
+    public function users(): void
+    {
+        redirect('providers');
+    }
+
+    /**
+     * Display settings page.
+     *
+     * Notice: Since the "settings" page is split into multiple pages (general, business, booking etc.), this method will
+     * redirect to "general" page by default.
+     */
+    public function settings(): void
+    {
+        redirect('general_settings');
+    }
+
+    /**
+     * Display the update page.
+     */
+    public function update(): void
+    {
+        redirect('update');
+    }
+}

application/controllers/Backend_api.php

@@ -0,0 +1,307 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/*
+|------------------------------------------------------------------------------
+| Deprecation Notice
+|------------------------------------------------------------------------------
+|
+| This file is still in the project for backwards compatibility reasons and for 
+| providing additional information on how to migrate your code to the latest   
+| codebase state. 
+|
+| Visit the Easy!Appointments Developers website for more information:  
+|
+|   https://developers.easyappointments.org
+|
+| Since v1.5, the methods of this controller were ported to standalone controller 
+| classes, that can both handle the page rendering and all asynchronous HTTP  
+| requests. 
+|
+*/
+
+/**
+ * Backend API controller.
+ *
+ * Handles the backend API related operations.
+ *
+ * @package Controllers
+ *
+ * @deprecated Since 1.5
+ */
+class Backend_api extends EA_Controller
+{
+    /**
+     * Get Calendar Events
+     */
+    public function ajax_get_calendar_events(): void
+    {
+        redirect('calendar/get_calendar_appointments_for_table_view');
+    }
+
+    /**
+     * Get the registered appointments for the given date period and record.
+     */
+    public function ajax_get_calendar_appointments(): void
+    {
+        redirect('calendar/get_calendar_appointments');
+    }
+
+    /**
+     * Save appointment changes that are made from the backend calendar page.
+     */
+    public function ajax_save_appointment(): void
+    {
+        redirect('calendar/save_appointment');
+    }
+
+    /**
+     * Delete appointment from the database.
+     */
+    public function ajax_delete_appointment(): void
+    {
+        redirect('calendar/delete_appointment');
+    }
+
+    /**
+     * Disable a providers sync setting.
+     */
+    public function ajax_disable_provider_sync(): void
+    {
+        redirect('google/disable_provider_sync');
+    }
+
+    /**
+     * Filter the customer records with the given key string.
+     */
+    public function ajax_filter_customers(): void
+    {
+        redirect('customers/search');
+    }
+
+    /**
+     * Insert or update an unavailability.
+     */
+    public function ajax_save_unavailability(): void
+    {
+        redirect('calendar/save_unavailability');
+    }
+
+    /**
+     * Delete an unavailability time period from database.
+     */
+    public function ajax_delete_unavailability(): void
+    {
+        redirect('calendar/delete_unavailability');
+    }
+
+    /**
+     * Insert of update working plan exceptions to database.
+     */
+    public function ajax_save_working_plan_exception(): void
+    {
+        redirect('calendar/save_working_plan_exception');
+    }
+
+    /**
+     * Delete a working plan exceptions time period to database.
+     */
+    public function ajax_delete_working_plan_exception(): void
+    {
+        redirect('calendar/delete_working_plan_exception');
+    }
+
+    /**
+     * Save (insert or update) a customer record.
+     */
+    public function ajax_save_customer(): void
+    {
+        redirect('customers/create'); // or "customers/update"
+    }
+
+    /**
+     * Delete customer from database.
+     */
+    public function ajax_delete_customer(): void
+    {
+        redirect('customers/destroy');
+    }
+
+    /**
+     * Save (insert or update) service record.
+     */
+    public function ajax_save_service(): void
+    {
+        redirect('services/create'); // or "services/update"
+    }
+
+    /**
+     * Delete service record from database.
+     */
+    public function ajax_delete_service(): void
+    {
+        redirect('services/destroy');
+    }
+
+    /**
+     * Filter service records by given key string.
+     */
+    public function ajax_filter_services(): void
+    {
+        redirect('services/search');
+    }
+
+    /**
+     * Save (insert or update) category record.
+     */
+    public function ajax_save_service_category(): void
+    {
+        redirect('categories/create'); // or "categories/update"
+    }
+
+    /**
+     * Delete category record from database.
+     */
+    public function ajax_delete_service_category(): void
+    {
+        redirect('categories/destroy');
+    }
+
+    /**
+     * Filter services categories with key string.
+     */
+    public function ajax_filter_service_categories(): void
+    {
+        redirect('categories/search');
+    }
+
+    /**
+     * Filter admin records with string key.
+     */
+    public function ajax_filter_admins(): void
+    {
+        redirect('admins/search');
+    }
+
+    /**
+     * Save (insert or update) admin record into database.
+     */
+    public function ajax_save_admin(): void
+    {
+        redirect('admins/create'); // or "admins/update"
+    }
+
+    /**
+     * Delete an admin record from the database.
+     */
+    public function ajax_delete_admin(): void
+    {
+        redirect('admins/destroy');
+    }
+
+    /**
+     * Filter provider records with string key.
+     */
+    public function ajax_filter_providers(): void
+    {
+        redirect('providers/search');
+    }
+
+    /**
+     * Save (insert or update) a provider record into database.
+     */
+    public function ajax_save_provider(): void
+    {
+        redirect('providers/create'); // or "providers/update"
+    }
+
+    /**
+     * Delete a provider record from the database.
+     */
+    public function ajax_delete_provider(): void
+    {
+        redirect('providers/destroy');
+    }
+
+    /**
+     * Filter secretary records with string key.
+     */
+    public function ajax_filter_secretaries(): void
+    {
+        redirect('secretaries/search');
+    }
+
+    /**
+     * Save (insert or update) a secretary record into database.
+     */
+    public function ajax_save_secretary(): void
+    {
+        redirect('secretaries/create'); // or "secretaries/update"
+    }
+
+    /**
+     * Delete a secretary record from the database.
+     */
+    public function ajax_delete_secretary(): void
+    {
+        redirect('secretaries/destroy');
+    }
+
+    /**
+     * Save a setting or multiple settings in the database.
+     */
+    public function ajax_save_settings(): void
+    {
+        redirect('general_settings/save'); // or "business_settings/save", "booking_settings/save", "legal_settings/save"
+    }
+
+    /**
+     * This method checks whether the username already exists in the database.
+     */
+    public function ajax_validate_username(): void
+    {
+        redirect('account/validate_username');
+    }
+
+    /**
+     * Change system language for current user.
+     */
+    public function ajax_change_language(): void
+    {
+        redirect('account/change_language');
+    }
+
+    /**
+     * This method will return a list of the available Google Calendars.
+     */
+    public function ajax_get_google_calendars(): void
+    {
+        redirect('google/get_google_calendars');
+    }
+
+    /**
+     * Select a specific google calendar for a provider.
+     */
+    public function ajax_select_google_calendar(): void
+    {
+        redirect('google/select_google_calendar');
+    }
+
+    /**
+     * Apply global working plan to all providers.
+     */
+    public function ajax_apply_global_working_plan(): void
+    {
+        redirect('business_settings/apply_global_working_plan');
+    }
+}

application/controllers/Blocked_periods.php

@@ -0,0 +1,220 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Blocked_periods controller.
+ *
+ * Handles the blocked-periods related operations.
+ *
+ * @package Controllers
+ */
+class Blocked_periods extends EA_Controller
+{
+    public array $allowed_blocked_period_fields = ['id', 'name', 'start_datetime', 'end_datetime', 'notes'];
+
+    public array $optional_blocked_period_fields = [
+        //
+    ];
+
+    /**
+     * Blocked_periods constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('blocked_periods_model');
+        $this->load->model('roles_model');
+
+        $this->load->library('accounts');
+        $this->load->library('timezones');
+        $this->load->library('webhooks_client');
+    }
+
+    /**
+     * Render the backend blocked-periods page.
+     *
+     * On this page admin users will be able to manage blocked-periods, which are eventually selected by customers during the
+     * booking process.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('blocked_periods')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_BLOCKED_PERIODS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'date_format' => setting('date_format'),
+            'time_format' => setting('time_format'),
+            'first_weekday' => setting('first_weekday'),
+        ]);
+
+        html_vars([
+            'page_title' => lang('blocked_periods'),
+            'active_menu' => PRIV_BLOCKED_PERIODS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+            'timezones' => $this->timezones->to_array(),
+            'privileges' => $this->roles_model->get_permissions_by_slug($role_slug),
+        ]);
+
+        $this->load->view('pages/blocked_periods');
+    }
+
+    /**
+     * Filter blocked-periods by the provided keyword.
+     */
+    public function search(): void
+    {
+        try {
+            if (cannot('view', PRIV_BLOCKED_PERIODS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $keyword = request('keyword', '');
+
+            $order_by = request('order_by', 'update_datetime DESC');
+
+            $limit = request('limit', 1000);
+
+            $offset = (int) request('offset', '0');
+
+            $blocked_periods = $this->blocked_periods_model->search($keyword, $limit, $offset, $order_by);
+
+            json_response($blocked_periods);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new service-category.
+     */
+    public function store(): void
+    {
+        try {
+            if (cannot('add', PRIV_BLOCKED_PERIODS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $blocked_period = request('blocked_period');
+
+            $this->blocked_periods_model->only($blocked_period, $this->allowed_blocked_period_fields);
+
+            $this->blocked_periods_model->optional($blocked_period, $this->optional_blocked_period_fields);
+
+            $blocked_period_id = $this->blocked_periods_model->save($blocked_period);
+
+            $blocked_period = $this->blocked_periods_model->find($blocked_period_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_BLOCKED_PERIOD_SAVE, $blocked_period);
+
+            json_response([
+                'success' => true,
+                'id' => $blocked_period_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Find a service-category.
+     */
+    public function find(): void
+    {
+        try {
+            if (cannot('view', PRIV_BLOCKED_PERIODS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $blocked_period_id = request('blocked_period_id');
+
+            $blocked_period = $this->blocked_periods_model->find($blocked_period_id);
+
+            json_response($blocked_period);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a service-category.
+     */
+    public function update(): void
+    {
+        try {
+            if (cannot('edit', PRIV_BLOCKED_PERIODS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $blocked_period = request('blocked_period');
+
+            $this->blocked_periods_model->only($blocked_period, $this->allowed_blocked_period_fields);
+
+            $this->blocked_periods_model->optional($blocked_period, $this->optional_blocked_period_fields);
+
+            $blocked_period_id = $this->blocked_periods_model->save($blocked_period);
+
+            $blocked_period = $this->blocked_periods_model->find($blocked_period_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_BLOCKED_PERIOD_SAVE, $blocked_period);
+
+            json_response([
+                'success' => true,
+                'id' => $blocked_period_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Remove a service-category.
+     */
+    public function destroy(): void
+    {
+        try {
+            if (cannot('delete', PRIV_BLOCKED_PERIODS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $blocked_period_id = request('blocked_period_id');
+
+            $blocked_period = $this->blocked_periods_model->find($blocked_period_id);
+
+            $this->blocked_periods_model->delete($blocked_period_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_BLOCKED_PERIOD_DELETE, $blocked_period);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Booking.php

@@ -0,0 +1,772 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Booking controller.
+ *
+ * Handles the booking related operations.
+ *
+ * Notice: This file used to have the booking page related code which since v1.5 has now moved to the Booking.php
+ * controller for improved consistency.
+ *
+ * @package Controllers
+ */
+class Booking extends EA_Controller
+{
+    public array $allowed_customer_fields = [
+        'id',
+        'first_name',
+        'last_name',
+        'email',
+        'phone_number',
+        'address',
+        'city',
+        'state',
+        'zip_code',
+        'timezone',
+        'language',
+        'custom_field_1',
+        'custom_field_2',
+        'custom_field_3',
+        'custom_field_4',
+        'custom_field_5',
+    ];
+    public mixed $allowed_provider_fields = ['id', 'first_name', 'last_name', 'services', 'timezone'];
+    public array $allowed_appointment_fields = [
+        'id',
+        'start_datetime',
+        'end_datetime',
+        'location',
+        'notes',
+        'color',
+        'status',
+        'is_unavailability',
+        'id_users_provider',
+        'id_users_customer',
+        'id_services',
+    ];
+
+    /**
+     * Booking constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('appointments_model');
+        $this->load->model('providers_model');
+        $this->load->model('admins_model');
+        $this->load->model('secretaries_model');
+        $this->load->model('service_categories_model');
+        $this->load->model('services_model');
+        $this->load->model('customers_model');
+        $this->load->model('settings_model');
+        $this->load->model('consents_model');
+
+        $this->load->library('timezones');
+        $this->load->library('synchronization');
+        $this->load->library('notifications');
+        $this->load->library('availability');
+        $this->load->library('webhooks_client');
+    }
+
+    /**
+     * Render the booking page and display the selected appointment.
+     *
+     * This method will call the "index" callback to handle the page rendering.
+     *
+     * @param string $appointment_hash
+     */
+    public function reschedule(string $appointment_hash): void
+    {
+        html_vars(['appointment_hash' => $appointment_hash]);
+
+        $this->index();
+    }
+
+    /**
+     * Render the booking page.
+     *
+     * This method creates the appointment book wizard.
+     */
+    public function index(): void
+    {
+        if (!is_app_installed()) {
+            redirect('installation');
+
+            return;
+        }
+
+        $company_name = setting('company_name');
+        $company_logo = setting('company_logo');
+        $company_color = setting('company_color');
+        $disable_booking = setting('disable_booking');
+        $google_analytics_code = setting('google_analytics_code');
+        $matomo_analytics_url = setting('matomo_analytics_url');
+        $matomo_analytics_site_id = setting('matomo_analytics_site_id');
+
+        if ($disable_booking) {
+            $disable_booking_message = setting('disable_booking_message');
+
+            html_vars([
+                'show_message' => true,
+                'page_title' => lang('page_title') . ' ' . $company_name,
+                'message_title' => lang('booking_is_disabled'),
+                'message_text' => $disable_booking_message,
+                'message_icon' => base_url('assets/img/error.png'),
+                'google_analytics_code' => $google_analytics_code,
+                'matomo_analytics_url' => $matomo_analytics_url,
+                'matomo_analytics_site_id' => $matomo_analytics_site_id,
+            ]);
+
+            $this->load->view('pages/booking_message');
+
+            return;
+        }
+
+        $available_services = $this->services_model->get_available_services(true);
+        $available_providers = $this->providers_model->get_available_providers(true);
+
+        foreach ($available_providers as &$available_provider) {
+            // Only expose the required provider data.
+
+            $this->providers_model->only($available_provider, $this->allowed_provider_fields);
+        }
+
+        $date_format = setting('date_format');
+        $time_format = setting('time_format');
+        $first_weekday = setting('first_weekday');
+        $display_first_name = setting('display_first_name');
+        $require_first_name = setting('require_first_name');
+        $display_last_name = setting('display_last_name');
+        $require_last_name = setting('require_last_name');
+        $display_email = setting('display_email');
+        $require_email = setting('require_email');
+        $display_phone_number = setting('display_phone_number');
+        $require_phone_number = setting('require_phone_number');
+        $display_address = setting('display_address');
+        $require_address = setting('require_address');
+        $display_city = setting('display_city');
+        $require_city = setting('require_city');
+        $display_zip_code = setting('display_zip_code');
+        $require_zip_code = setting('require_zip_code');
+        $display_notes = setting('display_notes');
+        $require_notes = setting('require_notes');
+        $display_cookie_notice = setting('display_cookie_notice');
+        $cookie_notice_content = setting('cookie_notice_content');
+        $display_terms_and_conditions = setting('display_terms_and_conditions');
+        $terms_and_conditions_content = setting('terms_and_conditions_content');
+        $display_privacy_policy = setting('display_privacy_policy');
+        $privacy_policy_content = setting('privacy_policy_content');
+        $display_any_provider = setting('display_any_provider');
+        $display_login_button = setting('display_login_button');
+        $display_delete_personal_information = setting('display_delete_personal_information');
+        $book_advance_timeout = setting('book_advance_timeout');
+        $theme = request('theme', setting('theme', 'default'));
+
+        if (empty($theme) || !file_exists(__DIR__ . '/../../assets/css/themes/' . $theme . '.min.css')) {
+            $theme = 'default';
+        }
+
+        $timezones = $this->timezones->to_array();
+        $grouped_timezones = $this->timezones->to_grouped_array();
+
+        $appointment_hash = html_vars('appointment_hash');
+
+        if (!empty($appointment_hash)) {
+            // Load the appointments data and enable the manage mode of the booking page.
+
+            $manage_mode = true;
+
+            $results = $this->appointments_model->get(['hash' => $appointment_hash]);
+
+            if (empty($results)) {
+                html_vars([
+                    'show_message' => true,
+                    'page_title' => lang('page_title') . ' ' . $company_name,
+                    'message_title' => lang('appointment_not_found'),
+                    'message_text' => lang('appointment_does_not_exist_in_db'),
+                    'message_icon' => base_url('assets/img/error.png'),
+                    'google_analytics_code' => $google_analytics_code,
+                    'matomo_analytics_url' => $matomo_analytics_url,
+                    'matomo_analytics_site_id' => $matomo_analytics_site_id,
+                ]);
+
+                $this->load->view('pages/booking_message');
+
+                return;
+            }
+
+            // Make sure the appointment can still be rescheduled.
+
+            $start_datetime = strtotime($results[0]['start_datetime']);
+
+            $limit = strtotime('+' . $book_advance_timeout . ' minutes', strtotime('now'));
+
+            if ($start_datetime < $limit) {
+                $hours = floor($book_advance_timeout / 60);
+
+                $minutes = $book_advance_timeout % 60;
+
+                html_vars([
+                    'show_message' => true,
+                    'page_title' => lang('page_title') . ' ' . $company_name,
+                    'message_title' => lang('appointment_locked'),
+                    'message_text' => strtr(lang('appointment_locked_message'), [
+                        '{$limit}' => sprintf('%02d:%02d', $hours, $minutes),
+                    ]),
+                    'message_icon' => base_url('assets/img/error.png'),
+                    'google_analytics_code' => $google_analytics_code,
+                    'matomo_analytics_url' => $matomo_analytics_url,
+                    'matomo_analytics_site_id' => $matomo_analytics_site_id,
+                ]);
+
+                $this->load->view('pages/booking_message');
+
+                return;
+            }
+
+            $appointment = $results[0];
+            $provider = $this->providers_model->find($appointment['id_users_provider']);
+            $customer = $this->customers_model->find($appointment['id_users_customer']);
+            $customer_token = md5(uniqid(mt_rand(), true));
+
+            // Cache the token for 10 minutes.
+            $this->cache->save('customer-token-' . $customer_token, $customer['id'], 600);
+        } else {
+            $manage_mode = false;
+            $customer_token = false;
+            $appointment = null;
+            $provider = null;
+            $customer = null;
+        }
+
+        script_vars([
+            'manage_mode' => $manage_mode,
+            'available_services' => $available_services,
+            'available_providers' => $available_providers,
+            'date_format' => $date_format,
+            'time_format' => $time_format,
+            'first_weekday' => $first_weekday,
+            'display_cookie_notice' => $display_cookie_notice,
+            'display_any_provider' => setting('display_any_provider'),
+            'future_booking_limit' => setting('future_booking_limit'),
+            'appointment_data' => $appointment,
+            'provider_data' => $provider,
+            'customer_data' => $customer,
+            'default_language' => setting('default_language'),
+            'default_timezone' => setting('default_timezone'),
+        ]);
+
+        html_vars([
+            'available_services' => $available_services,
+            'available_providers' => $available_providers,
+            'theme' => $theme,
+            'company_name' => $company_name,
+            'company_logo' => $company_logo,
+            'company_color' => $company_color === '#ffffff' ? '' : $company_color,
+            'date_format' => $date_format,
+            'time_format' => $time_format,
+            'first_weekday' => $first_weekday,
+            'display_first_name' => $display_first_name,
+            'require_first_name' => $require_first_name,
+            'display_last_name' => $display_last_name,
+            'require_last_name' => $require_last_name,
+            'display_email' => $display_email,
+            'require_email' => $require_email,
+            'display_phone_number' => $display_phone_number,
+            'require_phone_number' => $require_phone_number,
+            'display_address' => $display_address,
+            'require_address' => $require_address,
+            'display_city' => $display_city,
+            'require_city' => $require_city,
+            'display_zip_code' => $display_zip_code,
+            'require_zip_code' => $require_zip_code,
+            'display_notes' => $display_notes,
+            'require_notes' => $require_notes,
+            'display_cookie_notice' => $display_cookie_notice,
+            'cookie_notice_content' => $cookie_notice_content,
+            'display_terms_and_conditions' => $display_terms_and_conditions,
+            'terms_and_conditions_content' => $terms_and_conditions_content,
+            'display_privacy_policy' => $display_privacy_policy,
+            'privacy_policy_content' => $privacy_policy_content,
+            'display_any_provider' => $display_any_provider,
+            'display_login_button' => $display_login_button,
+            'display_delete_personal_information' => $display_delete_personal_information,
+            'google_analytics_code' => $google_analytics_code,
+            'matomo_analytics_url' => $matomo_analytics_url,
+            'matomo_analytics_site_id' => $matomo_analytics_site_id,
+            'timezones' => $timezones,
+            'grouped_timezones' => $grouped_timezones,
+            'manage_mode' => $manage_mode,
+            'customer_token' => $customer_token,
+            'appointment_data' => $appointment,
+            'provider_data' => $provider,
+            'customer_data' => $customer,
+        ]);
+
+        $this->load->view('pages/booking');
+    }
+
+    /**
+     * Register the appointment to the database.
+     */
+    public function register(): void
+    {
+        try {
+            $disable_booking = setting('disable_booking');
+
+            if ($disable_booking) {
+                abort(403);
+            }
+
+            $post_data = request('post_data');
+            $captcha = request('captcha');
+            $appointment = $post_data['appointment'];
+            $customer = $post_data['customer'];
+            $manage_mode = filter_var($post_data['manage_mode'], FILTER_VALIDATE_BOOLEAN);
+
+            if (!array_key_exists('address', $customer)) {
+                $customer['address'] = '';
+            }
+
+            if (!array_key_exists('city', $customer)) {
+                $customer['city'] = '';
+            }
+
+            if (!array_key_exists('zip_code', $customer)) {
+                $customer['zip_code'] = '';
+            }
+
+            if (!array_key_exists('notes', $customer)) {
+                $customer['notes'] = '';
+            }
+
+            if (!array_key_exists('phone_number', $customer)) {
+                $customer['phone_number'] = '';
+            }
+
+            // Check appointment availability before registering it to the database.
+            $appointment['id_users_provider'] = $this->check_datetime_availability();
+
+            if (!$appointment['id_users_provider']) {
+                throw new RuntimeException(lang('requested_hour_is_unavailable'));
+            }
+
+            $provider = $this->providers_model->find($appointment['id_users_provider']);
+
+            $service = $this->services_model->find($appointment['id_services']);
+
+            $require_captcha = (bool) setting('require_captcha');
+
+            $captcha_phrase = session('captcha_phrase');
+
+            // Validate the CAPTCHA string.
+
+            if ($require_captcha && strtoupper($captcha_phrase) !== strtoupper($captcha)) {
+                json_response([
+                    'captcha_verification' => false,
+                ]);
+
+                return;
+            }
+
+            if ($this->customers_model->exists($customer)) {
+                $customer['id'] = $this->customers_model->find_record_id($customer);
+
+                $existing_appointments = $this->appointments_model->get([
+                    'id !=' => $manage_mode ? $appointment['id'] : null,
+                    'id_users_customer' => $customer['id'],
+                    'start_datetime <=' => $appointment['start_datetime'],
+                    'end_datetime >=' => $appointment['end_datetime'],
+                ]);
+
+                if (count($existing_appointments)) {
+                    throw new RuntimeException(lang('customer_is_already_booked'));
+                }
+            }
+
+            if (empty($appointment['location']) && !empty($service['location'])) {
+                $appointment['location'] = $service['location'];
+            }
+
+            if (empty($appointment['color']) && !empty($service['color'])) {
+                $appointment['color'] = $service['color'];
+            }
+
+            $customer_ip = $this->input->ip_address();
+
+            // Create the consents (if needed).
+            $consent = [
+                'first_name' => $customer['first_name'] ?? '-',
+                'last_name' => $customer['last_name'] ?? '-',
+                'email' => $customer['email'] ?? '-',
+                'ip' => $customer_ip,
+            ];
+
+            if (setting('display_terms_and_conditions')) {
+                $consent['type'] = 'terms-and-conditions';
+
+                $this->consents_model->save($consent);
+            }
+
+            if (setting('display_privacy_policy')) {
+                $consent['type'] = 'privacy-policy';
+
+                $this->consents_model->save($consent);
+            }
+
+            // Save customer language (the language which is used to render the booking page).
+            $customer['language'] = session('language') ?? config('language');
+
+            $this->customers_model->only($customer, $this->allowed_customer_fields);
+
+            $customer_id = $this->customers_model->save($customer);
+            $customer = $this->customers_model->find($customer_id);
+
+            $appointment['id_users_customer'] = $customer_id;
+            $appointment['is_unavailability'] = false;
+            $appointment['color'] = $service['color'];
+
+            $appointment_status_options_json = setting('appointment_status_options', '[]');
+            $appointment_status_options = json_decode($appointment_status_options_json, true) ?? [];
+            $appointment['status'] = $appointment_status_options[0] ?? null;
+
+            $this->appointments_model->only($appointment, $this->allowed_appointment_fields);
+
+            $appointment_id = $this->appointments_model->save($appointment);
+            $appointment = $this->appointments_model->find($appointment_id);
+
+            $company_color = setting('company_color');
+
+            $settings = [
+                'company_name' => setting('company_name'),
+                'company_link' => setting('company_link'),
+                'company_email' => setting('company_email'),
+                'company_color' => !empty($company_color) && $company_color != DEFAULT_COMPANY_COLOR ? $company_color : null,
+                'date_format' => setting('date_format'),
+                'time_format' => setting('time_format'),
+            ];
+
+            $this->synchronization->sync_appointment_saved($appointment, $service, $provider, $customer, $settings);
+
+            $this->notifications->notify_appointment_saved(
+                $appointment,
+                $service,
+                $provider,
+                $customer,
+                $settings,
+                $manage_mode,
+            );
+
+            $this->webhooks_client->trigger(WEBHOOK_APPOINTMENT_SAVE, $appointment);
+
+            $response = [
+                'appointment_id' => $appointment['id'],
+                'appointment_hash' => $appointment['hash'],
+            ];
+
+            json_response($response);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Check whether the provider is still available in the selected appointment date.
+     *
+     * It is possible that two or more customers select the same appointment date and time concurrently. The app won't
+     * allow this to happen, so one of the two will eventually get the selected date and the other one will have
+     * to choose for another one.
+     *
+     * Use this method just before the customer confirms the appointment registration. If the selected date was reserved
+     * in the meanwhile, the customer must be prompted to select another time.
+     *
+     * @return int|null Returns the ID of the provider that is available for the appointment.
+     *
+     * @throws Exception
+     */
+    protected function check_datetime_availability(): ?int
+    {
+        $post_data = request('post_data');
+
+        $appointment = $post_data['appointment'];
+
+        $appointment_start = new DateTime($appointment['start_datetime']);
+
+        $date = $appointment_start->format('Y-m-d');
+
+        $hour = $appointment_start->format('H:i');
+
+        if ($appointment['id_users_provider'] === ANY_PROVIDER) {
+            $appointment['id_users_provider'] = $this->search_any_provider($appointment['id_services'], $date, $hour);
+
+            return $appointment['id_users_provider'];
+        }
+
+        $service = $this->services_model->find($appointment['id_services']);
+
+        $exclude_appointment_id = $appointment['id'] ?? null;
+
+        $provider = $this->providers_model->find($appointment['id_users_provider']);
+
+        $available_hours = $this->availability->get_available_hours(
+            $date,
+            $service,
+            $provider,
+            $exclude_appointment_id,
+        );
+
+        $is_still_available = false;
+
+        $appointment_hour = date('H:i', strtotime($appointment['start_datetime']));
+
+        foreach ($available_hours as $available_hour) {
+            if ($appointment_hour === $available_hour) {
+                $is_still_available = true;
+                break;
+            }
+        }
+
+        return $is_still_available ? $appointment['id_users_provider'] : null;
+    }
+
+    /**
+     * Search for any provider that can handle the requested service.
+     *
+     * This method will return the database ID of the provider with the most available periods.
+     *
+     * @param int $service_id Service ID
+     * @param string $date Selected date (Y-m-d).
+     * @param string|null $hour Selected hour (H:i).
+     *
+     * @return int|null Returns the ID of the provider that can provide the service at the selected date.
+     *
+     * @throws Exception
+     */
+    protected function search_any_provider(int $service_id, string $date, ?string $hour = null): ?int
+    {
+        $available_providers = $this->providers_model->get_available_providers(true);
+
+        $service = $this->services_model->find($service_id);
+
+        $provider_id = null;
+
+        $max_hours_count = 0;
+
+        foreach ($available_providers as $provider) {
+            foreach ($provider['services'] as $provider_service_id) {
+                if ($provider_service_id == $service_id) {
+                    // Check if the provider is available for the requested date.
+                    $available_hours = $this->availability->get_available_hours($date, $service, $provider);
+
+                    if (
+                        count($available_hours) > $max_hours_count &&
+                        (empty($hour) || in_array($hour, $available_hours))
+                    ) {
+                        $provider_id = $provider['id'];
+
+                        $max_hours_count = count($available_hours);
+                    }
+                }
+            }
+        }
+
+        return $provider_id;
+    }
+
+    /**
+     * Get the available appointment hours for the selected date.
+     *
+     * This method answers to an AJAX request. It calculates the available hours for the given service, provider and
+     * date.
+     */
+    public function get_available_hours(): void
+    {
+        try {
+            $disable_booking = setting('disable_booking');
+
+            if ($disable_booking) {
+                abort(403);
+            }
+
+            $provider_id = request('provider_id');
+            $service_id = request('service_id');
+            $selected_date = request('selected_date');
+
+            // Do not continue if there was no provider selected (more likely there is no provider in the system).
+
+            if (empty($provider_id)) {
+                json_response();
+
+                return;
+            }
+
+            // If manage mode is TRUE then the following we should not consider the selected appointment when
+            // calculating the available time periods of the provider.
+
+            $exclude_appointment_id = request('manage_mode') ? request('appointment_id') : null;
+
+            // If the user has selected the "any-provider" option then we will need to search for an available provider
+            // that will provide the requested service.
+
+            $service = $this->services_model->find($service_id);
+
+            if ($provider_id === ANY_PROVIDER) {
+                $providers = $this->providers_model->get();
+
+                $available_hours = [];
+
+                foreach ($providers as $provider) {
+                    if (!in_array($service_id, $provider['services'])) {
+                        continue;
+                    }
+
+                    $provider_available_hours = $this->availability->get_available_hours(
+                        $selected_date,
+                        $service,
+                        $provider,
+                        $exclude_appointment_id,
+                    );
+
+                    $available_hours = array_merge($available_hours, $provider_available_hours);
+                }
+
+                $available_hours = array_unique(array_values($available_hours));
+
+                sort($available_hours);
+
+                $response = $available_hours;
+            } else {
+                $provider = $this->providers_model->find($provider_id);
+
+                $response = $this->availability->get_available_hours(
+                    $selected_date,
+                    $service,
+                    $provider,
+                    $exclude_appointment_id,
+                );
+            }
+
+            json_response($response);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Get Unavailable Dates
+     *
+     * Get an array with the available dates of a specific provider, service and month of the year. Provide the
+     * "provider_id", "service_id" and "selected_date" as GET parameters to the request. The "selected_date" parameter
+     * must have the "Y-m-d" format.
+     *
+     * Outputs a JSON string with the unavailability dates. that are unavailability.
+     */
+    public function get_unavailable_dates(): void
+    {
+        try {
+            $disable_booking = setting('disable_booking');
+
+            if ($disable_booking) {
+                abort(403);
+            }
+
+            $provider_id = request('provider_id');
+            $service_id = request('service_id');
+            $appointment_id = request('appointment_id');
+            $manage_mode = filter_var(request('manage_mode'), FILTER_VALIDATE_BOOLEAN);
+            $selected_date_string = request('selected_date');
+            $selected_date = new DateTime($selected_date_string);
+            $number_of_days_in_month = (int) $selected_date->format('t');
+            $unavailable_dates = [];
+
+            $provider_ids =
+                $provider_id === ANY_PROVIDER ? $this->search_providers_by_service($service_id) : [$provider_id];
+
+            $exclude_appointment_id = $manage_mode ? $appointment_id : null;
+
+            // Get the service record.
+            $service = $this->services_model->find($service_id);
+
+            for ($i = 1; $i <= $number_of_days_in_month; $i++) {
+                $current_date = new DateTime($selected_date->format('Y-m') . '-' . $i);
+
+                if ($current_date < new DateTime(date('Y-m-d 00:00:00'))) {
+                    // Past dates become immediately unavailability.
+                    $unavailable_dates[] = $current_date->format('Y-m-d');
+                    continue;
+                }
+
+                // Finding at least one slot of availability.
+                foreach ($provider_ids as $current_provider_id) {
+                    $provider = $this->providers_model->find($current_provider_id);
+
+                    $available_hours = $this->availability->get_available_hours(
+                        $current_date->format('Y-m-d'),
+                        $service,
+                        $provider,
+                        $exclude_appointment_id,
+                    );
+
+                    if (!empty($available_hours)) {
+                        break;
+                    }
+                }
+
+                // No availability amongst all the provider.
+                if (empty($available_hours)) {
+                    $unavailable_dates[] = $current_date->format('Y-m-d');
+                }
+            }
+
+            if (count($unavailable_dates) === $number_of_days_in_month) {
+                json_response([
+                    'is_month_unavailable' => true,
+                ]);
+
+                return;
+            }
+
+            json_response($unavailable_dates);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Search for any provider that can handle the requested service.
+     *
+     * This method will return the database ID of the providers affected to the requested service.
+     *
+     * @param int $service_id The requested service ID.
+     *
+     * @return array Returns the ID of the provider that can provide the requested service.
+     */
+    protected function search_providers_by_service(int $service_id): array
+    {
+        $available_providers = $this->providers_model->get_available_providers(true);
+        $provider_list = [];
+
+        foreach ($available_providers as $provider) {
+            foreach ($provider['services'] as $provider_service_id) {
+                if ($provider_service_id === $service_id) {
+                    // Check if the provider is affected to the selected service.
+                    $provider_list[] = $provider['id'];
+                }
+            }
+        }
+
+        return $provider_list;
+    }
+}

application/controllers/Booking_cancellation.php

@@ -0,0 +1,130 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Booking cancellation controller.
+ *
+ * Handles the booking cancellation related operations.
+ *
+ * @package Controllers
+ */
+class Booking_cancellation extends EA_Controller
+{
+    /**
+     * Booking_cancellation constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('appointments_model');
+        $this->load->model('providers_model');
+        $this->load->model('services_model');
+        $this->load->model('customers_model');
+
+        $this->load->library('synchronization');
+        $this->load->library('notifications');
+        $this->load->library('webhooks_client');
+    }
+
+    /**
+     * Cancel an existing appointment.
+     *
+     * This method removes an appointment from the company's schedule. In order for the appointment to be deleted, the
+     * hash string must be provided. The customer can only cancel the appointment if the edit time period is not over
+     * yet.
+     *
+     * @param string $appointment_hash This appointment hash identifier.
+     */
+    public function of(string $appointment_hash): void
+    {
+        try {
+            $disable_booking = setting('disable_booking');
+
+            if ($disable_booking) {
+                abort(403);
+            }
+
+            $cancellation_reason = request('cancellation_reason');
+
+            if ($this->input->method() !== 'post' || empty($cancellation_reason)) {
+                abort(403, 'Forbidden');
+            }
+
+            $occurrences = $this->appointments_model->get(['hash' => $appointment_hash]);
+
+            if (empty($occurrences)) {
+                html_vars([
+                    'page_title' => lang('appointment_not_found'),
+                    'company_color' => setting('company_color'),
+                    'message_title' => lang('appointment_not_found'),
+                    'message_text' => lang('appointment_does_not_exist_in_db'),
+                    'message_icon' => base_url('assets/img/error.png'),
+                    'google_analytics_code' => setting('google_analytics_code'),
+                    'matomo_analytics_url' => setting('matomo_analytics_url'),
+                    'matomo_analytics_site_id' => setting('matomo_analytics_site_id'),
+                ]);
+
+                $this->load->view('pages/booking_message');
+
+                return;
+            }
+
+            $appointment = $occurrences[0];
+
+            $provider = $this->providers_model->find($appointment['id_users_provider']);
+
+            $customer = $this->customers_model->find($appointment['id_users_customer']);
+
+            $service = $this->services_model->find($appointment['id_services']);
+
+            $company_color = setting('company_color');
+
+            $settings = [
+                'company_name' => setting('company_name'),
+                'company_email' => setting('company_email'),
+                'company_link' => setting('company_link'),
+                'company_color' => !empty($company_color) && $company_color != DEFAULT_COMPANY_COLOR ? $company_color : null,
+                'date_format' => setting('date_format'),
+                'time_format' => setting('time_format'),
+            ];
+
+            $this->appointments_model->delete($appointment['id']);
+
+            $this->synchronization->sync_appointment_deleted($appointment, $provider);
+
+            $this->notifications->notify_appointment_deleted(
+                $appointment,
+                $service,
+                $provider,
+                $customer,
+                $settings,
+                $cancellation_reason,
+            );
+
+            $this->webhooks_client->trigger(WEBHOOK_APPOINTMENT_DELETE, $appointment);
+        } catch (Throwable $e) {
+            log_message('error', 'Booking Cancellation Exception: ' . $e->getMessage());
+        }
+
+        html_vars([
+            'page_title' => lang('appointment_cancelled_title'),
+            'company_color' => setting('company_color'),
+            'google_analytics_code' => setting('google_analytics_code'),
+            'matomo_analytics_url' => setting('matomo_analytics_url'),
+            'matomo_analytics_site_id' => setting('matomo_analytics_site_id'),
+        ]);
+
+        $this->load->view('pages/booking_cancellation');
+    }
+}

application/controllers/Booking_confirmation.php

@@ -0,0 +1,70 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Booking confirmation controller.
+ *
+ * Handles the booking confirmation related operations.
+ *
+ * @package Controllers
+ */
+class Booking_confirmation extends EA_Controller
+{
+    /**
+     * Booking_confirmation constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('appointments_model');
+        $this->load->model('providers_model');
+        $this->load->model('services_model');
+        $this->load->model('customers_model');
+
+        $this->load->library('google_sync');
+    }
+
+    /**
+     * Display the appointment registration success page.
+     *
+     * @throws Exception
+     */
+    public function of(): void
+    {
+        $appointment_hash = $this->uri->segment(3);
+
+        $occurrences = $this->appointments_model->get(['hash' => $appointment_hash]);
+
+        if (empty($occurrences)) {
+            redirect('appointments'); // The appointment does not exist.
+
+            return;
+        }
+
+        $appointment = $occurrences[0];
+
+        $add_to_google_url = $this->google_sync->get_add_to_google_url($appointment['id']);
+
+        html_vars([
+            'page_title' => lang('success'),
+            'company_color' => setting('company_color'),
+            'google_analytics_code' => setting('google_analytics_code'),
+            'matomo_analytics_url' => setting('matomo_analytics_url'),
+            'matomo_analytics_site_id' => setting('matomo_analytics_site_id'),
+            'add_to_google_url' => $add_to_google_url,
+        ]);
+
+        $this->load->view('pages/booking_confirmation');
+    }
+}

application/controllers/Booking_settings.php

@@ -0,0 +1,121 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Booking settings controller.
+ *
+ * Handles booking settings related operations.
+ *
+ * @package Controllers
+ */
+class Booking_settings extends EA_Controller
+{
+    public array $allowed_setting_fields = ['id', 'name', 'value'];
+
+    public array $optional_setting_fields = [
+        //
+    ];
+
+    /**
+     * Booking_settings constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('appointments_model');
+        $this->load->model('customers_model');
+        $this->load->model('services_model');
+        $this->load->model('providers_model');
+        $this->load->model('roles_model');
+        $this->load->model('settings_model');
+
+        $this->load->library('accounts');
+        $this->load->library('google_sync');
+        $this->load->library('notifications');
+        $this->load->library('synchronization');
+        $this->load->library('timezones');
+    }
+
+    /**
+     * Render the settings page.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('booking_settings')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_SYSTEM_SETTINGS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'booking_settings' => $this->settings_model->get_batch(),
+        ]);
+
+        html_vars([
+            'page_title' => lang('settings'),
+            'active_menu' => PRIV_SYSTEM_SETTINGS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+        ]);
+
+        $this->load->view('pages/booking_settings');
+    }
+
+    /**
+     * Save booking settings.
+     */
+    public function save(): void
+    {
+        try {
+            if (cannot('edit', PRIV_SYSTEM_SETTINGS)) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $settings = request('booking_settings', []);
+
+            foreach ($settings as $setting) {
+                $existing_setting = $this->settings_model
+                    ->query()
+                    ->where('name', $setting['name'])
+                    ->get()
+                    ->row_array();
+
+                if (!empty($existing_setting)) {
+                    $setting['id'] = $existing_setting['id'];
+                }
+
+                $this->settings_model->only($setting, $this->allowed_setting_fields);
+
+                $this->settings_model->optional($setting, $this->optional_setting_fields);
+
+                $this->settings_model->save($setting);
+            }
+
+            response();
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Business_settings.php

@@ -0,0 +1,147 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Business logic controller.
+ *
+ * Handles general settings related operations.
+ *
+ * @package Controllers
+ */
+class Business_settings extends EA_Controller
+{
+    public array $allowed_setting_fields = ['id', 'name', 'value'];
+
+    public array $optional_setting_fields = [
+        //
+    ];
+
+    /**
+     * Business_logic constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('appointments_model');
+        $this->load->model('customers_model');
+        $this->load->model('services_model');
+        $this->load->model('providers_model');
+        $this->load->model('roles_model');
+        $this->load->model('settings_model');
+
+        $this->load->library('accounts');
+        $this->load->library('google_sync');
+        $this->load->library('notifications');
+        $this->load->library('synchronization');
+        $this->load->library('timezones');
+    }
+
+    /**
+     * Render the settings page.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('business_settings')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_SYSTEM_SETTINGS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'business_settings' => $this->settings_model->get(),
+            'first_weekday' => setting('first_weekday'),
+            'time_format' => setting('time_format'),
+        ]);
+
+        html_vars([
+            'page_title' => lang('settings'),
+            'active_menu' => PRIV_SYSTEM_SETTINGS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+        ]);
+
+        $this->load->view('pages/business_settings');
+    }
+
+    /**
+     * Save general settings.
+     */
+    public function save(): void
+    {
+        try {
+            if (cannot('edit', PRIV_SYSTEM_SETTINGS)) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $settings = request('business_settings', []);
+
+            foreach ($settings as $setting) {
+                $existing_setting = $this->settings_model
+                    ->query()
+                    ->where('name', $setting['name'])
+                    ->get()
+                    ->row_array();
+
+                if (!empty($existing_setting)) {
+                    $setting['id'] = $existing_setting['id'];
+                }
+
+                $this->settings_model->only($setting, $this->allowed_setting_fields);
+
+                $this->settings_model->optional($setting, $this->optional_setting_fields);
+
+                $this->settings_model->save($setting);
+            }
+
+            response();
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Apply global working plan to all providers.
+     */
+    public function apply_global_working_plan(): void
+    {
+        try {
+            if (cannot('edit', PRIV_SYSTEM_SETTINGS)) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $working_plan = request('working_plan');
+
+            $providers = $this->providers_model->get();
+
+            foreach ($providers as $provider) {
+                $this->providers_model->set_setting($provider['id'], 'working_plan', $working_plan);
+            }
+
+            response();
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Caldav.php

@@ -0,0 +1,315 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+use GuzzleHttp\Exception\GuzzleException;
+use Jsvrcek\ICS\Exception\CalendarEventException;
+
+/**
+ * Caldav controller.
+ *
+ * Handles the Caldav Calendar synchronization related operations.
+ *
+ * @package Controllers
+ */
+class Caldav extends EA_Controller
+{
+    /**
+     * Caldav constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('caldav_sync');
+
+        $this->load->model('appointments_model');
+        $this->load->model('unavailabilities_model');
+        $this->load->model('providers_model');
+    }
+
+    /**
+     * Connect to the target CalDAV server
+     *
+     * @return void
+     */
+    public function connect_to_server(): void
+    {
+        try {
+            $provider_id = request('provider_id');
+
+            $user_id = session('user_id');
+
+            if (cannot('edit', PRIV_USERS) && (int) $user_id !== (int) $provider_id) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $caldav_url = request('caldav_url');
+            $caldav_username = request('caldav_username');
+            $caldav_password = request('caldav_password');
+
+            $this->caldav_sync->test_connection($caldav_url, $caldav_username, $caldav_password);
+
+            $provider = $this->providers_model->find($provider_id);
+
+            $provider['settings']['caldav_sync'] = true;
+            $provider['settings']['caldav_url'] = $caldav_url;
+            $provider['settings']['caldav_username'] = $caldav_username;
+            $provider['settings']['caldav_password'] = $caldav_password;
+
+            $this->providers_model->save($provider);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (GuzzleException | InvalidArgumentException $e) {
+            json_response([
+                'success' => false,
+                'message' => $e->getMessage(),
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Sync the provider events with the remote CalDAV calendar.
+     *
+     * @param string $provider_id Provider ID (String because this is used with HTTP and CLI)
+     *
+     * @return void
+     *
+     * @throws CalendarEventException
+     * @throws Exception
+     * @throws Throwable
+     */
+    public static function sync(string $provider_id): void
+    {
+        /** @var EA_Controller $CI */
+        $CI = get_instance();
+
+        $CI->load->library('caldav_sync');
+
+        // Load the libraries as this method is called statically from the CLI command
+
+        $CI->load->model('appointments_model');
+        $CI->load->model('unavailabilities_model');
+        $CI->load->model('providers_model');
+        $CI->load->model('services_model');
+        $CI->load->model('customers_model');
+        $CI->load->model('settings_model');
+
+        $user_id = session('user_id');
+
+        if (!$user_id && !is_cli()) {
+            return;
+        }
+
+        if (empty($provider_id)) {
+            throw new InvalidArgumentException('No provider ID provided.');
+        }
+
+        $provider = $CI->providers_model->find($provider_id);
+
+        // Check whether the selected provider has the CalDAV Sync enabled.
+
+        if (!$provider['settings']['caldav_sync']) {
+            return; // The selected provider does not have the CalDAV Sync enabled.
+        }
+
+        // Fetch provider's appointments that belong to the sync time period.
+
+        $sync_past_days = $provider['settings']['sync_past_days'];
+
+        $sync_future_days = $provider['settings']['sync_future_days'];
+
+        $start_date_time = date('Y-m-d H:i:s', strtotime('-' . $sync_past_days . ' days'));
+
+        $end_date_time = date('Y-m-d H:i:s', strtotime('+' . $sync_future_days . ' days'));
+
+        $where = [
+            'start_datetime >=' => $start_date_time,
+            'end_datetime <=' => $end_date_time,
+            'id_users_provider' => $provider['id'],
+        ];
+
+        $appointments = $CI->appointments_model->get($where);
+
+        $unavailabilities = $CI->unavailabilities_model->get($where);
+
+        $local_events = [...$appointments, ...$unavailabilities];
+
+        // Sync each appointment with CalDAV Calendar by following the project's sync protocol (see documentation).
+
+        foreach ($local_events as $local_event) {
+            if (str_contains((string) $local_event['id_caldav_calendar'], 'RECURRENCE')) {
+                continue;
+            }
+
+            if (!$local_event['is_unavailability']) {
+                $service = $CI->services_model->find($local_event['id_services']);
+                $customer = $CI->customers_model->find($local_event['id_users_customer']);
+                $events_model = $CI->appointments_model;
+            } else {
+                $service = null;
+                $customer = null;
+                $events_model = $CI->unavailabilities_model;
+            }
+
+            if (!$local_event['id_caldav_calendar']) {
+                if (!$local_event['is_unavailability']) {
+                    $caldav_event_id = $CI->caldav_sync->save_appointment($local_event, $service, $provider, $customer);
+                } else {
+                    $caldav_event_id = $CI->caldav_sync->save_unavailability($local_event, $provider);
+                }
+
+                $local_event['id_caldav_calendar'] = $caldav_event_id;
+
+                $events_model->save($local_event); // Save the CalDAV Calendar ID.
+
+                continue;
+            }
+
+            // Appointment is synced with CalDAV Calendar.
+
+            try {
+                $caldav_event = $CI->caldav_sync->get_event($provider, $local_event['id_caldav_calendar']);
+
+                if (!$caldav_event || $caldav_event['status'] === 'CANCELLED') {
+                    throw new Exception('Event is cancelled, remove the record from Easy!Appointments.');
+                }
+
+                // If CalDAV Calendar event is different from Easy!Appointments appointment then update Easy!Appointments record.
+                $local_event_start = strtotime($local_event['start_datetime']);
+                $local_event_end = strtotime($local_event['end_datetime']);
+
+                $caldav_event_start = new DateTime($caldav_event['start_datetime']);
+                $caldav_event_end = new DateTime($caldav_event['end_datetime']);
+
+                $is_different =
+                    $local_event_start !== $caldav_event_start->getTimestamp() ||
+                    $local_event_end !== $caldav_event_end->getTimestamp() ||
+                    $local_event['notes'] !== $caldav_event['description'];
+
+                if ($is_different) {
+                    $local_event['start_datetime'] = $caldav_event_start->format('Y-m-d H:i:s');
+                    $local_event['end_datetime'] = $caldav_event_end->format('Y-m-d H:i:s');
+                    $local_event['notes'] = $caldav_event['description'];
+                    $events_model->save($local_event);
+                }
+            } catch (Throwable) {
+                // Appointment not found on CalDAV Calendar, delete from Easy!Appointments.
+                $events_model->delete($local_event['id']);
+
+                $local_event['id_caldav_calendar'] = null;
+            }
+        }
+
+        // Add CalDAV Calendar events that do not exist in Easy!Appointments.
+
+        try {
+            $caldav_events = $CI->caldav_sync->get_sync_events($provider, $start_date_time, $end_date_time);
+        } catch (Throwable $e) {
+            if ($e->getCode() === 404) {
+                log_message('error', 'CalDAV - Remote Calendar not found for provider ID: ' . $provider_id);
+
+                return; // The remote calendar was not found.
+            } else {
+                throw $e;
+            }
+        }
+
+        $CI->appointments_model->delete_caldav_recurring_events($start_date_time, $end_date_time);
+
+        foreach ($caldav_events as $caldav_event) {
+            if ($caldav_event['status'] === 'CANCELLED') {
+                continue;
+            }
+
+            if ($caldav_event['start_datetime'] === $caldav_event['end_datetime']) {
+                continue; // Cannot sync events with the same start and end date time value
+            }
+
+            $appointment_results = $CI->appointments_model->get(['id_caldav_calendar' => $caldav_event['id']]);
+
+            if (!empty($appointment_results)) {
+                continue;
+            }
+
+            $unavailability_results = $CI->unavailabilities_model->get([
+                'id_caldav_calendar' => $caldav_event['id'],
+            ]);
+
+            if (!empty($unavailability_results)) {
+                continue;
+            }
+
+            // Record doesn't exist in the Easy!Appointments, so add the event now.
+
+            $local_event = [
+                'start_datetime' => $caldav_event['start_datetime'],
+                'end_datetime' => $caldav_event['end_datetime'],
+                'location' => $caldav_event['location'],
+                'notes' => $caldav_event['summary'] . ' ' . $caldav_event['description'],
+                'id_users_provider' => $provider_id,
+                'id_caldav_calendar' => $caldav_event['id'],
+            ];
+
+            $CI->unavailabilities_model->save($local_event);
+        }
+
+        json_response([
+            'success' => true,
+        ]);
+    }
+
+    /**
+     * Disable a providers sync setting.
+     *
+     * This method resets the CalDAV related settings from the user_settings DB table.
+     *
+     * @return void
+     */
+    public function disable_provider_sync(): void
+    {
+        try {
+            $provider_id = request('provider_id');
+
+            if (!$provider_id) {
+                throw new Exception('Provider id not specified.');
+            }
+
+            $user_id = session('user_id');
+
+            if (cannot('edit', PRIV_USERS) && (int) $user_id !== (int) $provider_id) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $provider = $this->providers_model->find($provider_id);
+
+            $provider['settings']['caldav_sync'] = false;
+            $provider['settings']['caldav_url'] = null;
+            $provider['settings']['caldav_username'] = null;
+            $provider['settings']['caldav_password'] = null;
+
+            $this->providers_model->save($provider);
+
+            $this->appointments_model->clear_caldav_sync_ids($provider_id);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Calendar.php

@@ -0,0 +1,807 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Calendar controller.
+ *
+ * Handles calendar related operations.
+ *
+ * @package Controllers
+ */
+class Calendar extends EA_Controller
+{
+    public array $allowed_customer_fields = [
+        'id',
+        'first_name',
+        'last_name',
+        'email',
+        'phone_number',
+        'address',
+        'city',
+        'state',
+        'zip_code',
+        'timezone',
+        'language',
+        'notes',
+        'custom_field_1',
+        'custom_field_2',
+        'custom_field_3',
+        'custom_field_4',
+        'custom_field_5',
+    ];
+
+    public array $optional_customer_fields = [
+        //
+    ];
+
+    public array $allowed_appointment_fields = [
+        'id',
+        'start_datetime',
+        'end_datetime',
+        'location',
+        'notes',
+        'color',
+        'status',
+        'is_unavailability',
+        'id_users_provider',
+        'id_users_customer',
+        'id_services',
+    ];
+
+    public array $optional_appointment_fields = [
+        //
+    ];
+
+    /**
+     * Calendar constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('appointments_model');
+        $this->load->model('unavailabilities_model');
+        $this->load->model('blocked_periods_model');
+        $this->load->model('customers_model');
+        $this->load->model('services_model');
+        $this->load->model('providers_model');
+        $this->load->model('roles_model');
+
+        $this->load->library('accounts');
+        $this->load->library('google_sync');
+        $this->load->library('notifications');
+        $this->load->library('synchronization');
+        $this->load->library('timezones');
+        $this->load->library('webhooks_client');
+    }
+
+    /**
+     * Render the calendar page and display the selected appointment.
+     *
+     * This method will call the "index" callback to handle the page rendering.
+     *
+     * @param string $appointment_hash Appointment hash.
+     */
+    public function reschedule(string $appointment_hash): void
+    {
+        $this->index($appointment_hash);
+    }
+
+    /**
+     * Display the main backend page.
+     *
+     * This method displays the main backend page. All login permission can view this page which displays a calendar
+     * with the events of the selected provider or service. If a user has more privileges he will see more menus at the
+     * top of the page.
+     *
+     * @param string $appointment_hash Appointment hash.
+     */
+    public function index(string $appointment_hash = ''): void
+    {
+        session([
+            'dest_url' => site_url('calendar/index' . (!empty($appointment_hash) ? '/' . $appointment_hash : '')),
+        ]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_APPOINTMENTS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        $user = $this->users_model->find($user_id);
+
+        $secretary_providers = [];
+
+        if ($role_slug === DB_SLUG_SECRETARY) {
+            $secretary = $this->secretaries_model->find(session('user_id'));
+
+            $secretary_providers = $secretary['providers'];
+        }
+
+        $edit_appointment = null;
+
+        if (!empty($appointment_hash)) {
+            $occurrences = $this->appointments_model->get(['hash' => $appointment_hash]);
+
+            if ($appointment_hash !== '' && !empty($occurrences)) {
+                $edit_appointment = $occurrences[0];
+
+                $this->appointments_model->load($edit_appointment, ['customer']);
+            }
+        }
+
+        $privileges = $this->roles_model->get_permissions_by_slug($role_slug);
+
+        $available_providers = $this->providers_model->get_available_providers();
+
+        if ($role_slug === DB_SLUG_PROVIDER) {
+            $available_providers = array_values(
+                array_filter($available_providers, function ($available_provider) use ($user_id) {
+                    return (int) $available_provider['id'] === (int) $user_id;
+                }),
+            );
+        }
+
+        if ($role_slug === DB_SLUG_SECRETARY) {
+            $available_providers = array_values(
+                array_filter($available_providers, function ($available_provider) use ($secretary_providers) {
+                    return in_array($available_provider['id'], $secretary_providers);
+                }),
+            );
+        }
+
+        $available_services = $this->services_model->get_available_services();
+
+        $calendar_view = request('view', $user['settings']['calendar_view']);
+
+        $appointment_status_options = setting('appointment_status_options');
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'date_format' => setting('date_format'),
+            'time_format' => setting('time_format'),
+            'first_weekday' => setting('first_weekday'),
+            'company_working_plan' => setting('company_working_plan'),
+            'timezones' => $this->timezones->to_array(),
+            'privileges' => $privileges,
+            'calendar_view' => $calendar_view,
+            'available_providers' => $available_providers,
+            'available_services' => $available_services,
+            'secretary_providers' => $secretary_providers,
+            'edit_appointment' => $edit_appointment,
+            'google_sync_feature' => config('google_sync_feature'),
+            'customers' => $this->customers_model->get(null, 50, null, 'update_datetime DESC'),
+            'default_language' => setting('default_language'),
+            'default_timezone' => setting('default_timezone'),
+        ]);
+
+        html_vars([
+            'page_title' => lang('calendar'),
+            'active_menu' => PRIV_APPOINTMENTS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+            'timezone' => session('timezone'),
+            'timezones' => $this->timezones->to_array(),
+            'grouped_timezones' => $this->timezones->to_grouped_array(),
+            'privileges' => $privileges,
+            'calendar_view' => $calendar_view,
+            'available_providers' => $available_providers,
+            'available_services' => $available_services,
+            'secretary_providers' => $secretary_providers,
+            'appointment_status_options' => json_decode($appointment_status_options, true) ?? [],
+            'require_first_name' => setting('require_first_name'),
+            'require_last_name' => setting('require_last_name'),
+            'require_email' => setting('require_email'),
+            'require_phone_number' => setting('require_phone_number'),
+            'require_address' => setting('require_address'),
+            'require_city' => setting('require_city'),
+            'require_zip_code' => setting('require_zip_code'),
+            'require_notes' => setting('require_notes'),
+        ]);
+
+        $this->load->view('pages/calendar');
+    }
+
+    /**
+     * Save appointment changes that are made from the backend calendar page.
+     */
+    public function save_appointment(): void
+    {
+        try {
+            $customer_data = request('customer_data');
+
+            $appointment_data = request('appointment_data');
+
+            $this->check_event_permissions((int) $appointment_data['id_users_provider']);
+
+            // Save customer changes to the database.
+            if ($customer_data) {
+                $customer = $customer_data;
+
+                $required_permissions = !empty($customer['id'])
+                    ? can('add', PRIV_CUSTOMERS)
+                    : can('edit', PRIV_CUSTOMERS);
+
+                if (!$required_permissions) {
+                    throw new RuntimeException('You do not have the required permissions for this task.');
+                }
+
+                $this->customers_model->only($customer, $this->allowed_customer_fields);
+
+                $this->customers_model->optional($customer, $this->optional_customer_fields);
+
+                $customer['id'] = $this->customers_model->save($customer);
+            }
+
+            // Save appointment changes to the database.
+            $manage_mode = !empty($appointment_data['id']);
+
+            if ($appointment_data) {
+                $appointment = $appointment_data;
+
+                $required_permissions = !empty($appointment['id'])
+                    ? can('add', PRIV_APPOINTMENTS)
+                    : can('edit', PRIV_APPOINTMENTS);
+
+                if (!$required_permissions) {
+                    throw new RuntimeException('You do not have the required permissions for this task.');
+                }
+
+                // If the appointment does not contain the customer record id, then it means that is going to be inserted.
+
+                if (!isset($appointment['id_users_customer'])) {
+                    $appointment['id_users_customer'] = $customer['id'] ?? $customer_data['id'];
+                }
+
+                if ($manage_mode && !empty($appointment['id'])) {
+                    $this->synchronization->remove_appointment_on_provider_change($appointment['id']);
+                }
+
+                $this->appointments_model->only($appointment, $this->allowed_appointment_fields);
+
+                $this->appointments_model->optional($appointment, $this->optional_appointment_fields);
+
+                $appointment['id'] = $this->appointments_model->save($appointment);
+            }
+
+            if (empty($appointment['id'])) {
+                throw new RuntimeException('The appointment ID is not available.');
+            }
+
+            $appointment = $this->appointments_model->find($appointment['id']);
+            $provider = $this->providers_model->find($appointment['id_users_provider']);
+            $customer = $this->customers_model->find($appointment['id_users_customer']);
+            $service = $this->services_model->find($appointment['id_services']);
+
+            $company_color = setting('company_color');
+
+            $settings = [
+                'company_name' => setting('company_name'),
+                'company_link' => setting('company_link'),
+                'company_email' => setting('company_email'),
+                'company_color' => !empty($company_color) && $company_color != DEFAULT_COMPANY_COLOR ? $company_color : null,
+                'date_format' => setting('date_format'),
+                'time_format' => setting('time_format'),
+            ];
+
+            $this->synchronization->sync_appointment_saved($appointment, $service, $provider, $customer, $settings);
+
+            $this->notifications->notify_appointment_saved(
+                $appointment,
+                $service,
+                $provider,
+                $customer,
+                $settings,
+                $manage_mode,
+            );
+
+            $this->webhooks_client->trigger(WEBHOOK_APPOINTMENT_SAVE, $appointment);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    private function check_event_permissions(int $provider_id): void
+    {
+        $user_id = (int) session('user_id');
+        $role_slug = session('role_slug');
+
+        if (
+            $role_slug === DB_SLUG_SECRETARY &&
+            !$this->secretaries_model->is_provider_supported($user_id, $provider_id)
+        ) {
+            abort(403);
+        }
+
+        if ($role_slug === DB_SLUG_PROVIDER && $user_id !== $provider_id) {
+            abort(403);
+        }
+    }
+
+    /**
+     * Delete appointment from the database.
+     *
+     * This method deletes an existing appointment from the database. Once this action is finished it cannot be undone.
+     * Notification emails are send to both provider and customer and the delete action is executed to the Google
+     * Calendar account of the provider, if the "google_sync" setting is enabled.
+     */
+    public function delete_appointment(): void
+    {
+        try {
+            if (cannot('delete', 'appointments')) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $appointment_id = request('appointment_id');
+            $cancellation_reason = (string) request('cancellation_reason');
+
+            if (empty($appointment_id)) {
+                throw new InvalidArgumentException('No appointment id provided.');
+            }
+
+            // Store appointment data for later use in this method.
+            $appointment = $this->appointments_model->find($appointment_id);
+
+            $this->check_event_permissions((int) $appointment['id_users_provider']);
+
+            $provider = $this->providers_model->find($appointment['id_users_provider']);
+            $customer = $this->customers_model->find($appointment['id_users_customer']);
+            $service = $this->services_model->find($appointment['id_services']);
+
+            $company_color = setting('company_color');
+
+            $settings = [
+                'company_name' => setting('company_name'),
+                'company_email' => setting('company_email'),
+                'company_link' => setting('company_link'),
+                'company_color' => !empty($company_color) && $company_color != DEFAULT_COMPANY_COLOR ? $company_color : null,
+                'date_format' => setting('date_format'),
+                'time_format' => setting('time_format'),
+            ];
+
+            // Delete appointment record from the database.
+            $this->appointments_model->delete($appointment_id);
+
+            $this->notifications->notify_appointment_deleted(
+                $appointment,
+                $service,
+                $provider,
+                $customer,
+                $settings,
+                $cancellation_reason,
+            );
+
+            $this->synchronization->sync_appointment_deleted($appointment, $provider);
+
+            $this->webhooks_client->trigger(WEBHOOK_APPOINTMENT_DELETE, $appointment);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Insert of update unavailability to database.
+     */
+    public function save_unavailability(): void
+    {
+        try {
+            // Check privileges
+            $unavailability = request('unavailability');
+
+            $required_permissions = !isset($unavailability['id'])
+                ? can('add', PRIV_APPOINTMENTS)
+                : can('edit', PRIV_APPOINTMENTS);
+
+            if (!$required_permissions) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $provider_id = (int) $unavailability['id_users_provider'];
+
+            $this->check_event_permissions($provider_id);
+
+            $provider = $this->providers_model->find($provider_id);
+
+            $unavailability_id = $this->unavailabilities_model->save($unavailability);
+
+            $unavailability = $this->unavailabilities_model->find($unavailability_id);
+
+            $this->synchronization->sync_unavailability_saved($unavailability, $provider);
+
+            $this->webhooks_client->trigger(WEBHOOK_UNAVAILABILITY_SAVE, $unavailability);
+
+            json_response([
+                'success' => true,
+                'warnings' => $warnings ?? [],
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Delete an unavailability from database.
+     */
+    public function delete_unavailability(): void
+    {
+        try {
+            if (cannot('delete', PRIV_APPOINTMENTS)) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $unavailability_id = request('unavailability_id');
+
+            $unavailability = $this->unavailabilities_model->find($unavailability_id);
+
+            $this->check_event_permissions((int) $unavailability['id_users_provider']);
+
+            $provider = $this->providers_model->find($unavailability['id_users_provider']);
+
+            $this->unavailabilities_model->delete($unavailability_id);
+
+            $this->synchronization->sync_unavailability_deleted($unavailability, $provider);
+
+            $this->webhooks_client->trigger(WEBHOOK_UNAVAILABILITY_DELETE, $unavailability);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Insert of update working plan exceptions to database.
+     */
+    public function save_working_plan_exception(): void
+    {
+        try {
+            if (cannot('edit', PRIV_USERS)) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $date = request('date');
+
+            $original_date = request('original_date');
+
+            $working_plan_exception = request('working_plan_exception');
+
+            if (!$working_plan_exception) {
+                $working_plan_exception = null;
+            }
+
+            $provider_id = request('provider_id');
+
+            $this->providers_model->save_working_plan_exception($provider_id, $date, $working_plan_exception);
+
+            if ($original_date && $date !== $original_date) {
+                $this->providers_model->delete_working_plan_exception($provider_id, $original_date);
+            }
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Delete a working plan exceptions time period to database.
+     */
+    public function delete_working_plan_exception(): void
+    {
+        try {
+            $required_permissions = can('edit', PRIV_CUSTOMERS);
+
+            if (!$required_permissions) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $date = request('date');
+
+            $provider_id = request('provider_id');
+
+            $this->providers_model->delete_working_plan_exception($provider_id, $date);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Get Calendar Events
+     *
+     * This method will return all the calendar events within a specified period.
+     */
+    public function get_calendar_appointments_for_table_view(): void
+    {
+        try {
+            $required_permissions = can('view', PRIV_APPOINTMENTS);
+
+            if (!$required_permissions) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $start_date = request('start_date') . ' 00:00:00';
+
+            $end_date = request('end_date') . ' 23:59:59';
+
+            $response = [
+                'appointments' => $this->appointments_model->get([
+                    'start_datetime >=' => $start_date,
+                    'end_datetime <=' => $end_date,
+                ]),
+                'unavailabilities' => $this->unavailabilities_model->get([
+                    'start_datetime >=' => $start_date,
+                    'end_datetime <=' => $end_date,
+                ]),
+            ];
+
+            foreach ($response['appointments'] as &$appointment) {
+                $appointment['provider'] = $this->providers_model->find($appointment['id_users_provider']);
+                $appointment['service'] = $this->services_model->find($appointment['id_services']);
+                $appointment['customer'] = $this->customers_model->find($appointment['id_users_customer']);
+            }
+
+            unset($appointment);
+
+            $user_id = session('user_id');
+
+            $role_slug = session('role_slug');
+
+            // If the current user is a provider he must only see his own appointments.
+            if ($role_slug === DB_SLUG_PROVIDER) {
+                foreach ($response['appointments'] as $index => $appointment) {
+                    if ((int) $appointment['id_users_provider'] !== (int) $user_id) {
+                        unset($response['appointments'][$index]);
+                    }
+                }
+
+                $response['appointments'] = array_values($response['appointments']);
+
+                foreach ($response['unavailabilities'] as $index => $unavailability) {
+                    if ((int) $unavailability['id_users_provider'] !== (int) $user_id) {
+                        unset($response['unavailabilities'][$index]);
+                    }
+                }
+
+                $response['unavailabilities'] = array_values($response['unavailabilities']);
+            }
+
+            // If the current user is a secretary he must only see the appointments of his providers.
+            if ($role_slug === DB_SLUG_SECRETARY) {
+                $providers = $this->secretaries_model->find($user_id)['providers'];
+
+                foreach ($response['appointments'] as $index => $appointment) {
+                    if (!in_array((int) $appointment['id_users_provider'], $providers)) {
+                        unset($response['appointments'][$index]);
+                    }
+                }
+
+                $response['appointments'] = array_values($response['appointments']);
+
+                foreach ($response['unavailabilities'] as $index => $unavailability) {
+                    if (!in_array((int) $unavailability['id_users_provider'], $providers)) {
+                        unset($response['unavailabilities'][$index]);
+                    }
+                }
+
+                $response['unavailabilities'] = array_values($response['unavailabilities']);
+            }
+
+            foreach ($response['unavailabilities'] as &$unavailability) {
+                $unavailability['provider'] = $this->providers_model->find($unavailability['id_users_provider']);
+            }
+
+            unset($unavailability);
+
+            // Add blocked periods to the response.
+            $start_date = request('start_date');
+            $end_date = request('end_date');
+            $response['blocked_periods'] = $this->blocked_periods_model->get_for_period($start_date, $end_date);
+
+            json_response($response);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Get the registered appointments for the given date period and record.
+     *
+     * This method returns the database appointments and unavailability periods for the user selected date period and
+     * record type (provider or service).
+     */
+    public function get_calendar_appointments(): void
+    {
+        try {
+            if (cannot('view', PRIV_APPOINTMENTS)) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $record_id = request('record_id');
+
+            $is_all = request('record_id') === FILTER_TYPE_ALL;
+
+            $filter_type = request('filter_type');
+
+            if (!$filter_type && !$is_all) {
+                json_response([
+                    'appointments' => [],
+                    'unavailabilities' => [],
+                ]);
+
+                return;
+            }
+
+            $record_id = $this->db->escape($record_id);
+
+            if ($filter_type == FILTER_TYPE_PROVIDER) {
+                $where_id = 'id_users_provider';
+            } elseif ($filter_type === FILTER_TYPE_SERVICE) {
+                $where_id = 'id_services';
+            } else {
+                $where_id = $record_id;
+            }
+
+            // Get appointments
+            $start_date = $this->db->escape(request('start_date'));
+            $end_date = $this->db->escape(date('Y-m-d', strtotime(request('end_date') . ' +1 day')));
+
+            $where_clause =
+                $where_id .
+                ' = ' .
+                $record_id .
+                '
+                AND ((start_datetime > ' .
+                $start_date .
+                ' AND start_datetime < ' .
+                $end_date .
+                ') 
+                or (end_datetime > ' .
+                $start_date .
+                ' AND end_datetime < ' .
+                $end_date .
+                ') 
+                or (start_datetime <= ' .
+                $start_date .
+                ' AND end_datetime >= ' .
+                $end_date .
+                ')) 
+                AND is_unavailability = 0
+            ';
+
+            $response['appointments'] = $this->appointments_model->get($where_clause);
+
+            foreach ($response['appointments'] as &$appointment) {
+                $appointment['provider'] = $this->providers_model->find($appointment['id_users_provider']);
+                $appointment['service'] = $this->services_model->find($appointment['id_services']);
+                $appointment['customer'] = $this->customers_model->find($appointment['id_users_customer']);
+            }
+
+            unset($appointment);
+
+            // Get unavailability periods (only for provider).
+            $response['unavailabilities'] = [];
+
+            if ($filter_type == FILTER_TYPE_PROVIDER || $is_all) {
+                $where_clause =
+                    $where_id .
+                    ' = ' .
+                    $record_id .
+                    '
+                    AND ((start_datetime > ' .
+                    $start_date .
+                    ' AND start_datetime < ' .
+                    $end_date .
+                    ') 
+                    or (end_datetime > ' .
+                    $start_date .
+                    ' AND end_datetime < ' .
+                    $end_date .
+                    ') 
+                    or (start_datetime <= ' .
+                    $start_date .
+                    ' AND end_datetime >= ' .
+                    $end_date .
+                    ')) 
+                    AND is_unavailability = 1
+                ';
+
+                $response['unavailabilities'] = $this->unavailabilities_model->get($where_clause);
+            }
+
+            $user_id = session('user_id');
+
+            $role_slug = session('role_slug');
+
+            // If the current user is a provider he must only see his own appointments.
+            if ($role_slug === DB_SLUG_PROVIDER) {
+                foreach ($response['appointments'] as $index => $appointment) {
+                    if ((int) $appointment['id_users_provider'] !== (int) $user_id) {
+                        unset($response['appointments'][$index]);
+                    }
+                }
+
+                $response['appointments'] = array_values($response['appointments']);
+
+                foreach ($response['unavailabilities'] as $index => $unavailability) {
+                    if ((int) $unavailability['id_users_provider'] !== (int) $user_id) {
+                        unset($response['unavailabilities'][$index]);
+                    }
+                }
+
+                unset($unavailability);
+
+                $response['unavailabilities'] = array_values($response['unavailabilities']);
+            }
+
+            // If the current user is a secretary he must only see the appointments of his providers.
+            if ($role_slug === DB_SLUG_SECRETARY) {
+                $providers = $this->secretaries_model->find($user_id)['providers'];
+
+                foreach ($response['appointments'] as $index => $appointment) {
+                    if (!in_array((int) $appointment['id_users_provider'], $providers)) {
+                        unset($response['appointments'][$index]);
+                    }
+                }
+
+                $response['appointments'] = array_values($response['appointments']);
+
+                foreach ($response['unavailabilities'] as $index => $unavailability) {
+                    if (!in_array((int) $unavailability['id_users_provider'], $providers)) {
+                        unset($response['unavailabilities'][$index]);
+                    }
+                }
+
+                $response['unavailabilities'] = array_values($response['unavailabilities']);
+            }
+
+            foreach ($response['unavailabilities'] as &$unavailability) {
+                $unavailability['provider'] = $this->providers_model->find($unavailability['id_users_provider']);
+            }
+
+            unset($unavailability);
+
+            // Add blocked periods to the response.
+            $start_date = request('start_date');
+            $end_date = request('end_date');
+            $response['blocked_periods'] = $this->blocked_periods_model->get_for_period($start_date, $end_date);
+
+            json_response($response);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Captcha.php

@@ -0,0 +1,47 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Captcha controller.
+ *
+ * Handles the captcha operations.
+ *
+ * @package Controllers
+ */
+class Captcha extends EA_Controller
+{
+    /**
+     * Class Constructor
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('captcha_builder');
+    }
+
+    /**
+     * Make a request to this method to get a captcha image.
+     */
+    public function index(): void
+    {
+        $this->captcha_builder->setDistortion(true);
+        $this->captcha_builder->setMaxBehindLines(1);
+        $this->captcha_builder->setMaxFrontLines(1);
+        $this->captcha_builder->setBackgroundColor(255, 255, 255);
+        $this->captcha_builder->build();
+        session(['captcha_phrase' => $this->captcha_builder->getPhrase()]);
+        header('Content-type: image/jpeg');
+        $this->captcha_builder->output();
+    }
+}

application/controllers/Consents.php

@@ -0,0 +1,73 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.3.2
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Consents controller.
+ *
+ * Handles user consent related operations.
+ *
+ * @package Controllers
+ */
+class Consents extends EA_Controller
+{
+    /**
+     * Consents constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('consents_model');
+    }
+
+    /**
+     * Save (insert or update) the consent
+     */
+    public function save(): void
+    {
+        try {
+            $consent = request('consent');
+
+            $consent['ip'] = $this->input->ip_address();
+
+            $occurrences = $this->consents_model->get(['ip' => $consent['ip']], 1, 0, 'create_datetime DESC');
+
+            if (!empty($occurrences)) {
+                $last_consent = $occurrences[0];
+
+                $last_consent_create_datetime_instance = new DateTime($last_consent['create_datetime']);
+
+                $threshold_datetime_instance = new DateTime('-24 hours');
+
+                if ($last_consent_create_datetime_instance > $threshold_datetime_instance) {
+                    // Do not create a new consent.
+
+                    json_response([
+                        'success' => true,
+                    ]);
+
+                    return;
+                }
+            }
+
+            $consent['id'] = $this->consents_model->save($consent);
+
+            json_response([
+                'success' => true,
+                'id' => $consent['id'],
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Console.php

@@ -0,0 +1,193 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.3.2
+ * ---------------------------------------------------------------------------- */
+
+use Jsvrcek\ICS\Exception\CalendarEventException;
+
+require_once __DIR__ . '/Google.php';
+require_once __DIR__ . '/Caldav.php';
+
+/**
+ * Console controller.
+ *
+ * Handles all the Console related operations.
+ */
+class Console extends EA_Controller
+{
+    /**
+     * Console constructor.
+     */
+    public function __construct()
+    {
+        if (!is_cli()) {
+            exit('No direct script access allowed');
+        }
+
+        parent::__construct();
+
+        $this->load->dbutil();
+
+        $this->load->library('instance');
+
+        $this->load->model('admins_model');
+        $this->load->model('customers_model');
+        $this->load->model('providers_model');
+        $this->load->model('services_model');
+        $this->load->model('settings_model');
+    }
+
+    /**
+     * Perform a console installation.
+     *
+     * Use this method to install Easy!Appointments directly from the terminal.
+     *
+     * Usage:
+     *
+     * php index.php console install
+     *
+     * @throws Exception
+     */
+    public function install(): void
+    {
+        $this->instance->migrate('fresh');
+
+        $password = $this->instance->seed();
+
+        response(
+            PHP_EOL . '⇾ Installation completed, login with "administrator" / "' . $password . '".' . PHP_EOL . PHP_EOL,
+        );
+    }
+
+    /**
+     * Migrate the database to the latest state.
+     *
+     * Use this method to upgrade an Easy!Appointments instance to the latest database state.
+     *
+     * Notice:
+     *
+     * Do not use this method to install the app as it will not seed the database with the initial entries (admin,
+     * provider, service, settings etc.).
+     *
+     * Usage:
+     *
+     * php index.php console migrate
+     *
+     * php index.php console migrate fresh
+     *
+     * @param string $type
+     */
+    public function migrate(string $type = ''): void
+    {
+        $this->instance->migrate($type);
+    }
+
+    /**
+     * Seed the database with test data.
+     *
+     * Use this method to add test data to your database
+     *
+     * Usage:
+     *
+     * php index.php console seed
+     * @throws Exception
+     */
+    public function seed(): void
+    {
+        $this->instance->seed();
+    }
+
+    /**
+     * Create a database backup file.
+     *
+     * Use this method to back up your Easy!Appointments data.
+     *
+     * Usage:
+     *
+     * php index.php console backup
+     *
+     * php index.php console backup /path/to/backup/folder
+     *
+     * @throws Exception
+     */
+    public function backup(): void
+    {
+        $this->instance->backup($GLOBALS['argv'][3] ?? null);
+    }
+
+    /**
+     * Trigger the synchronization of all provider calendars with Google Calendar.
+     *
+     * Use this method in a cronjob to automatically sync events between Easy!Appointments and Google Calendar.
+     *
+     * Notice:
+     *
+     * Google syncing must first be enabled for each individual provider from inside the backend calendar page.
+     *
+     * Usage:
+     *
+     * php index.php console sync
+     *
+     * @throws CalendarEventException
+     * @throws Exception
+     * @throws Throwable
+     */
+    public function sync(): void
+    {
+        $providers = $this->providers_model->get();
+
+        foreach ($providers as $provider) {
+            if (filter_var($provider['settings']['google_sync'], FILTER_VALIDATE_BOOLEAN)) {
+                Google::sync((string) $provider['id']);
+            }
+
+            if (filter_var($provider['settings']['caldav_sync'], FILTER_VALIDATE_BOOLEAN)) {
+                Caldav::sync((string) $provider['id']);
+            }
+        }
+    }
+
+    /**
+     * Show help information about the console capabilities.
+     *
+     * Use this method to see the available commands.
+     *
+     * Usage:
+     *
+     * php index.php console help
+     */
+    public function help(): void
+    {
+        $help = [
+            '',
+            'Easy!Appointments ' . config('version'),
+            '',
+            'Usage:',
+            '',
+            '⇾ php index.php console [command] [arguments]',
+            '',
+            'Commands:',
+            '',
+            '⇾ php index.php console migrate',
+            '⇾ php index.php console migrate fresh',
+            '⇾ php index.php console migrate up',
+            '⇾ php index.php console migrate down',
+            '⇾ php index.php console seed',
+            '⇾ php index.php console install',
+            '⇾ php index.php console backup',
+            '⇾ php index.php console sync',
+            '',
+            '',
+        ];
+
+        response(implode(PHP_EOL, $help));
+    }
+}

application/controllers/Customers.php

@@ -0,0 +1,312 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Customers controller.
+ *
+ * Handles the customers related operations.
+ *
+ * @package Controllers
+ */
+class Customers extends EA_Controller
+{
+    public array $allowed_customer_fields = [
+        'id',
+        'first_name',
+        'last_name',
+        'email',
+        'phone_number',
+        'address',
+        'city',
+        'state',
+        'zip_code',
+        'notes',
+        'timezone',
+        'language',
+        'custom_field_1',
+        'custom_field_2',
+        'custom_field_3',
+        'custom_field_4',
+        'custom_field_5',
+        'ldap_dn',
+    ];
+
+    public array $optional_customer_fields = [
+        //
+    ];
+
+    /**
+     * Customers constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('appointments_model');
+        $this->load->model('customers_model');
+        $this->load->model('secretaries_model');
+        $this->load->model('roles_model');
+
+        $this->load->library('accounts');
+        $this->load->library('permissions');
+        $this->load->library('timezones');
+        $this->load->library('webhooks_client');
+    }
+
+    /**
+     * Render the backend customers page.
+     *
+     * On this page admin users will be able to manage customers, which are eventually selected by customers during the
+     * booking process.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('customers')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_CUSTOMERS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        $date_format = setting('date_format');
+        $time_format = setting('time_format');
+        $require_first_name = setting('require_first_name');
+        $require_last_name = setting('require_last_name');
+        $require_email = setting('require_email');
+        $require_phone_number = setting('require_phone_number');
+        $require_address = setting('require_address');
+        $require_city = setting('require_city');
+        $require_zip_code = setting('require_zip_code');
+
+        $secretary_providers = [];
+
+        if ($role_slug === DB_SLUG_SECRETARY) {
+            $secretary = $this->secretaries_model->find($user_id);
+
+            $secretary_providers = $secretary['providers'];
+        }
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'date_format' => $date_format,
+            'time_format' => $time_format,
+            'timezones' => $this->timezones->to_array(),
+            'secretary_providers' => $secretary_providers,
+            'default_language' => setting('default_language'),
+            'default_timezone' => setting('default_timezone'),
+        ]);
+
+        html_vars([
+            'page_title' => lang('customers'),
+            'active_menu' => PRIV_CUSTOMERS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+            'timezones' => $this->timezones->to_array(),
+            'grouped_timezones' => $this->timezones->to_grouped_array(),
+            'privileges' => $this->roles_model->get_permissions_by_slug($role_slug),
+            'require_first_name' => $require_first_name,
+            'require_last_name' => $require_last_name,
+            'require_email' => $require_email,
+            'require_phone_number' => $require_phone_number,
+            'require_address' => $require_address,
+            'require_city' => $require_city,
+            'require_zip_code' => $require_zip_code,
+            'available_languages' => config('available_languages'),
+        ]);
+
+        $this->load->view('pages/customers');
+    }
+
+    /**
+     * Find a customer.
+     */
+    public function find(): void
+    {
+        try {
+            if (cannot('view', PRIV_CUSTOMERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $user_id = session('user_id');
+
+            $customer_id = request('customer_id');
+
+            if (!$this->permissions->has_customer_access($user_id, $customer_id)) {
+                abort(403, 'Forbidden');
+            }
+
+            $customer = $this->customers_model->find($customer_id);
+
+            json_response($customer);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Filter customers by the provided keyword.
+     */
+    public function search(): void
+    {
+        try {
+            if (cannot('view', PRIV_CUSTOMERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $keyword = request('keyword', '');
+
+            $order_by = request('order_by', 'update_datetime DESC');
+
+            $limit = request('limit', 1000);
+
+            $offset = (int) request('offset', '0');
+
+            $customers = $this->customers_model->search($keyword, $limit, $offset, $order_by);
+
+            $user_id = session('user_id');
+
+            foreach ($customers as $index => &$customer) {
+                if (!$this->permissions->has_customer_access($user_id, $customer['id'])) {
+                    unset($customers[$index]);
+
+                    continue;
+                }
+
+                $appointments = $this->appointments_model->get(['id_users_customer' => $customer['id']]);
+
+                foreach ($appointments as &$appointment) {
+                    $this->appointments_model->load($appointment, ['service', 'provider']);
+                }
+
+                $customer['appointments'] = $appointments;
+            }
+
+            json_response(array_values($customers));
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new customer.
+     */
+    public function store(): void
+    {
+        try {
+            if (cannot('add', PRIV_CUSTOMERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            if (session('role_slug') !== DB_SLUG_ADMIN && setting('limit_customer_visibility')) {
+                abort(403);
+            }
+
+            $customer = request('customer');
+
+            $this->customers_model->only($customer, $this->allowed_customer_fields);
+
+            $this->customers_model->optional($customer, $this->optional_customer_fields);
+
+            $customer_id = $this->customers_model->save($customer);
+
+            $customer = $this->customers_model->find($customer_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_CUSTOMER_SAVE, $customer);
+
+            json_response([
+                'success' => true,
+                'id' => $customer_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a customer.
+     */
+    public function update(): void
+    {
+        try {
+            if (cannot('edit', PRIV_CUSTOMERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $user_id = session('user_id');
+
+            $customer = request('customer');
+
+            if (!$this->permissions->has_customer_access($user_id, $customer['id'])) {
+                abort(403, 'Forbidden');
+            }
+
+            $this->customers_model->only($customer, $this->allowed_customer_fields);
+
+            $this->customers_model->optional($customer, $this->optional_customer_fields);
+
+            $customer_id = $this->customers_model->save($customer);
+
+            $customer = $this->customers_model->find($customer_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_CUSTOMER_SAVE, $customer);
+
+            json_response([
+                'success' => true,
+                'id' => $customer_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Remove a customer.
+     */
+    public function destroy(): void
+    {
+        try {
+            if (cannot('delete', PRIV_CUSTOMERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $user_id = session('user_id');
+
+            $customer_id = request('customer_id');
+
+            if (!$this->permissions->has_customer_access($user_id, $customer_id)) {
+                abort(403, 'Forbidden');
+            }
+
+            $customer = $this->customers_model->find($customer_id);
+
+            $this->customers_model->delete($customer_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_CUSTOMER_DELETE, $customer);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/General_settings.php

@@ -0,0 +1,112 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * General settings controller.
+ *
+ * Handles general settings related operations.
+ *
+ * @package Controllers
+ */
+class General_settings extends EA_Controller
+{
+    /**
+     * Calendar constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('settings_model');
+
+        $this->load->library('accounts');
+        $this->load->library('timezones');
+    }
+
+    /**
+     * Render the settings page.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('general_settings')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_SYSTEM_SETTINGS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        $available_theme_files = glob(__DIR__ . '/../../assets/css/themes/*.min.css');
+
+        $available_themes = array_map(function ($available_theme_file) {
+            return str_replace('.min.css', '', basename($available_theme_file));
+        }, $available_theme_files);
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'timezones' => $this->timezones->to_array(),
+            'general_settings' => $this->settings_model->get(),
+        ]);
+
+        html_vars([
+            'page_title' => lang('settings'),
+            'active_menu' => PRIV_SYSTEM_SETTINGS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+            'grouped_timezones' => $this->timezones->to_grouped_array(),
+            'available_themes' => $available_themes,
+        ]);
+
+        $this->load->view('pages/general_settings');
+    }
+
+    /**
+     * Save general settings.
+     */
+    public function save(): void
+    {
+        try {
+            if (cannot('edit', PRIV_SYSTEM_SETTINGS)) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $settings = request('general_settings', []);
+
+            foreach ($settings as $setting) {
+                $existing_setting = $this->settings_model
+                    ->query()
+                    ->where('name', $setting['name'])
+                    ->get()
+                    ->row_array();
+
+                if (!empty($existing_setting)) {
+                    $setting['id'] = $existing_setting['id'];
+                }
+
+                $this->settings_model->save($setting);
+            }
+
+            response();
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Google.php

@@ -0,0 +1,439 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Google controller.
+ *
+ * Handles the Google Calendar synchronization related operations.
+ *
+ * @package Controllers
+ */
+class Google extends EA_Controller
+{
+    /**
+     * Google constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('google_sync');
+
+        $this->load->model('appointments_model');
+        $this->load->model('providers_model');
+        $this->load->model('roles_model');
+    }
+
+    /**
+     * Complete synchronization of appointments between Google Calendar and Easy!Appointments.
+     *
+     * This method will completely sync the appointments of a provider with his Google Calendar account. The sync period
+     * needs to be relatively small, because a lot of API calls might be necessary and this will lead to consuming the
+     * Google limit for the Calendar API usage.
+     */
+    public static function sync(?string $provider_id = null): void
+    {
+        try {
+            /** @var EA_Controller $CI */
+            $CI = get_instance();
+
+            $CI->load->library('google_sync');
+
+            // Load the libraries as this method is called statically from the CLI command
+
+            $CI->load->model('appointments_model');
+            $CI->load->model('unavailabilities_model');
+            $CI->load->model('providers_model');
+            $CI->load->model('services_model');
+            $CI->load->model('customers_model');
+            $CI->load->model('settings_model');
+
+            $user_id = session('user_id');
+
+            if (!$user_id && !is_cli()) {
+                return;
+            }
+
+            if (!$provider_id) {
+                throw new InvalidArgumentException('No provider ID provided.');
+            }
+
+            $provider = $CI->providers_model->find($provider_id);
+
+            // Check whether the selected provider has the Google Sync enabled.
+            $google_sync = $CI->providers_model->get_setting($provider['id'], 'google_sync');
+
+            if (!$google_sync) {
+                return; // The selected provider does not have the Google Sync enabled.
+            }
+
+            $google_token = json_decode($provider['settings']['google_token'], true);
+
+            $CI->google_sync->refresh_token($google_token['refresh_token']);
+
+            // Fetch provider's appointments that belong to the sync time period.
+            $sync_past_days = $provider['settings']['sync_past_days'];
+
+            $sync_future_days = $provider['settings']['sync_future_days'];
+
+            $start = strtotime('-' . $sync_past_days . ' days', strtotime(date('Y-m-d')));
+
+            $end = strtotime('+' . $sync_future_days . ' days', strtotime(date('Y-m-d')));
+
+            $where = [
+                'start_datetime >=' => date('Y-m-d H:i:s', $start),
+                'end_datetime <=' => date('Y-m-d H:i:s', $end),
+                'id_users_provider' => $provider['id'],
+            ];
+
+            $appointments = $CI->appointments_model->get($where);
+
+            $unavailabilities = $CI->unavailabilities_model->get($where);
+
+            $local_events = [...$appointments, ...$unavailabilities];
+
+            $company_color = setting('company_color');
+
+            $settings = [
+                'company_name' => setting('company_name'),
+                'company_link' => setting('company_link'),
+                'company_email' => setting('company_email'),
+                'company_color' => !empty($company_color) && $company_color != DEFAULT_COMPANY_COLOR ? $company_color : null,
+            ];
+
+            $provider_timezone = new DateTimeZone($provider['timezone']);
+
+            // Sync each appointment with Google Calendar by following the project's sync protocol (see documentation).
+            foreach ($local_events as $local_event) {
+                if (!$local_event['is_unavailability']) {
+                    $service = $CI->services_model->find($local_event['id_services']);
+                    $customer = $CI->customers_model->find($local_event['id_users_customer']);
+                    $events_model = $CI->appointments_model;
+                } else {
+                    $service = null;
+                    $customer = null;
+                    $events_model = $CI->unavailabilities_model;
+                }
+
+                // If current appointment not synced yet, add to Google Calendar.
+                if (!$local_event['id_google_calendar']) {
+                    if (!$local_event['is_unavailability']) {
+                        $google_event = $CI->google_sync->add_appointment(
+                            $local_event,
+                            $provider,
+                            $service,
+                            $customer,
+                            $settings,
+                        );
+                    } else {
+                        $google_event = $CI->google_sync->add_unavailability($provider, $local_event);
+                    }
+
+                    $local_event['id_google_calendar'] = $google_event->getId();
+
+                    $events_model->save($local_event); // Save the Google Calendar ID.
+
+                    continue;
+                }
+
+                // Appointment is synced with Google Calendar.
+
+                try {
+                    $google_event = $CI->google_sync->get_event($provider, $local_event['id_google_calendar']);
+
+                    if ($google_event->getStatus() == 'cancelled') {
+                        throw new Exception('Event is cancelled, remove the record from Easy!Appointments.');
+                    }
+
+                    // If Google Calendar event is different from Easy!Appointments appointment then update Easy!Appointments record.
+                    $local_event_start = strtotime($local_event['start_datetime']);
+                    $local_event_end = strtotime($local_event['end_datetime']);
+                    $google_event_start = new DateTime(
+                        $google_event->getStart()->getDateTime() ?? $google_event->getEnd()->getDate(),
+                    );
+                    $google_event_start->setTimezone($provider_timezone);
+                    $google_event_end = new DateTime(
+                        $google_event->getEnd()->getDateTime() ?? $google_event->getEnd()->getDate(),
+                    );
+                    $google_event_end->setTimezone($provider_timezone);
+
+                    $google_event_notes = $local_event['is_unavailability']
+                        ? $google_event->getSummary() . ' ' . $google_event->getDescription()
+                        : $google_event->getDescription();
+
+                    $is_different =
+                        $local_event_start !== $google_event_start->getTimestamp() ||
+                        $local_event_end !== $google_event_end->getTimestamp() ||
+                        $local_event['notes'] !== $google_event_notes;
+
+                    if ($is_different) {
+                        $local_event['start_datetime'] = $google_event_start->format('Y-m-d H:i:s');
+                        $local_event['end_datetime'] = $google_event_end->format('Y-m-d H:i:s');
+                        $local_event['notes'] = $google_event_notes;
+                        $events_model->save($local_event);
+                    }
+                } catch (Throwable) {
+                    // Appointment not found on Google Calendar, delete from Easy!Appointments.
+                    $events_model->delete($local_event['id']);
+
+                    $local_event['id_google_calendar'] = null;
+                }
+            }
+
+            // Add Google Calendar events that do not exist in Easy!Appointments.
+            $google_calendar = $provider['settings']['google_calendar'];
+
+            try {
+                $google_events = $CI->google_sync->get_sync_events($google_calendar, $start, $end);
+            } catch (Throwable $e) {
+                if ($e->getCode() === 404) {
+                    log_message('error', 'Google - Remote Calendar not found for provider ID: ' . $provider_id);
+
+                    return; // The remote calendar was not found.
+                } else {
+                    throw $e;
+                }
+            }
+
+            foreach ($google_events->getItems() as $google_event) {
+                if ($google_event->getStatus() === 'cancelled') {
+                    continue;
+                }
+
+                if ($google_event->getStart() === null || $google_event->getEnd() === null) {
+                    continue;
+                }
+
+                if ($google_event->getStart()->getDateTime() === $google_event->getEnd()->getDateTime()) {
+                    continue;
+                }
+
+                $google_event_start = new DateTime($google_event->getStart()->getDateTime());
+                $google_event_start->setTimezone($provider_timezone);
+                $google_event_end = new DateTime($google_event->getEnd()->getDateTime());
+                $google_event_end->setTimezone($provider_timezone);
+
+                $appointment_results = $CI->appointments_model->get(['id_google_calendar' => $google_event->getId()]);
+
+                if (!empty($appointment_results)) {
+                    continue;
+                }
+
+                $unavailability_results = $CI->unavailabilities_model->get([
+                    'id_google_calendar' => $google_event->getId(),
+                ]);
+
+                if (!empty($unavailability_results)) {
+                    continue;
+                }
+
+                // Record doesn't exist in the Easy!Appointments, so add the event now.
+                $local_event = [
+                    'start_datetime' => $google_event_start->format('Y-m-d H:i:s'),
+                    'end_datetime' => $google_event_end->format('Y-m-d H:i:s'),
+                    'is_unavailability' => true,
+                    'location' => $google_event->getLocation(),
+                    'notes' => $google_event->getSummary() . ' ' . $google_event->getDescription(),
+                    'id_users_provider' => $provider_id,
+                    'id_google_calendar' => $google_event->getId(),
+                    'id_users_customer' => null,
+                    'id_services' => null,
+                ];
+
+                $CI->unavailabilities_model->save($local_event);
+            }
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            log_message(
+                'error',
+                'Google - Sync completed with an error (provider ID "' . $provider_id . '"): ' . $e->getMessage(),
+            );
+
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Authorize Google Calendar API usage for a specific provider.
+     *
+     * Since it is required to follow the web application flow, in order to retrieve a refresh token from the Google API
+     * service, this method is going to authorize the given provider.
+     *
+     * @param string $provider_id The provider id, for whom the sync authorization is made.
+     */
+    public function oauth(string $provider_id): void
+    {
+        if (!$this->session->userdata('user_id')) {
+            show_error('Forbidden', 403);
+        }
+
+        // Store the provider id for use on the callback function.
+        session(['oauth_provider_id' => $provider_id]);
+
+        // Redirect browser to google user content page.
+        header('Location: ' . $this->google_sync->get_auth_url());
+    }
+
+    /**
+     * Callback method for the Google Calendar API authorization process.
+     *
+     * Once the user grants consent with his Google Calendar data usage, the Google OAuth service will redirect him back
+     * in this page. Here we are going to store the refresh token, because this is what will be used to generate access
+     * tokens in the future.
+     *
+     * IMPORTANT: Because it is necessary to authorize the application using the web server flow (see official
+     * documentation of OAuth), every Easy!Appointments installation should use its own calendar api key. So in every
+     * api console account, the "http://path-to-Easy!Appointments/google/oauth_callback" should be included in an
+     * allowed redirect URL.
+     *
+     * @throws Exception
+     */
+    public function oauth_callback(): void
+    {
+        if (!session('user_id')) {
+            abort(403, 'Forbidden');
+        }
+
+        $code = request('code');
+
+        if (empty($code)) {
+            response('Code authorization failed.');
+
+            return;
+        }
+
+        $token = $this->google_sync->authenticate($code);
+
+        if (empty($token)) {
+            response('Token authorization failed.');
+
+            return;
+        }
+
+        // Store the token into the database for future reference.
+        $oauth_provider_id = session('oauth_provider_id');
+
+        if ($oauth_provider_id) {
+            $this->providers_model->set_setting($oauth_provider_id, 'google_sync', true);
+            $this->providers_model->set_setting($oauth_provider_id, 'google_token', json_encode($token));
+            $this->providers_model->set_setting($oauth_provider_id, 'google_calendar', 'primary');
+        } else {
+            response('Sync provider id not specified.');
+        }
+    }
+
+    /**
+     * This method will return a list of the available Google Calendars.
+     *
+     * The user will need to select a specific calendar from this list to sync his appointments with. Google access must
+     * be already granted for the specific provider.
+     */
+    public function get_google_calendars(): void
+    {
+        try {
+            $provider_id = (int) request('provider_id');
+
+            if (empty($provider_id)) {
+                throw new Exception('Provider id is required in order to fetch the google calendars.');
+            }
+
+            // Check if selected provider has sync enabled.
+            $google_sync = $this->providers_model->get_setting($provider_id, 'google_sync');
+
+            if (!$google_sync) {
+                json_response([
+                    'success' => false,
+                ]);
+
+                return;
+            }
+
+            $google_token = json_decode($this->providers_model->get_setting($provider_id, 'google_token'), true);
+
+            $this->google_sync->refresh_token($google_token['refresh_token']);
+
+            $calendars = $this->google_sync->get_google_calendars();
+
+            json_response($calendars);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Select a specific google calendar for a provider.
+     *
+     * All the appointments will be synced with this particular calendar.
+     */
+    public function select_google_calendar(): void
+    {
+        try {
+            $provider_id = request('provider_id');
+
+            $user_id = session('user_id');
+
+            if (cannot('edit', PRIV_USERS) && (int) $user_id !== (int) $provider_id) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $calendar_id = request('calendar_id');
+
+            $this->providers_model->set_setting($provider_id, 'google_calendar', $calendar_id);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Disable a providers sync setting.
+     *
+     * This method deletes the "google_sync" and "google_token" settings from the database.
+     *
+     * After that the provider's appointments will be no longer synced with Google Calendar.
+     */
+    public function disable_provider_sync(): void
+    {
+        try {
+            $provider_id = request('provider_id');
+
+            if (!$provider_id) {
+                throw new Exception('Provider id not specified.');
+            }
+
+            $user_id = session('user_id');
+
+            if (cannot('edit', PRIV_USERS) && (int) $user_id !== (int) $provider_id) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $this->providers_model->set_setting($provider_id, 'google_sync', false);
+
+            $this->providers_model->set_setting($provider_id, 'google_token');
+
+            $this->appointments_model->clear_google_sync_ids($provider_id);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Google_analytics_settings.php

@@ -0,0 +1,102 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Google Analytics settings controller.
+ *
+ * Handles Google Analytics settings related operations.
+ *
+ * @package Controllers
+ */
+class Google_analytics_settings extends EA_Controller
+{
+    /**
+     * Google_analytics_settings constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('settings_model');
+
+        $this->load->library('accounts');
+    }
+
+    /**
+     * Render the settings page.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('google_analytics_settings')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_SYSTEM_SETTINGS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'google_analytics_settings' => $this->settings_model->get('name like "google_analytics_%"'),
+        ]);
+
+        html_vars([
+            'page_title' => lang('google_analytics'),
+            'active_menu' => PRIV_SYSTEM_SETTINGS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+        ]);
+
+        $this->load->view('pages/google_analytics_settings');
+    }
+
+    /**
+     * Save general settings.
+     */
+    public function save(): void
+    {
+        try {
+            if (cannot('edit', PRIV_SYSTEM_SETTINGS)) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $settings = request('google_analytics_settings', []);
+
+            foreach ($settings as $setting) {
+                $existing_setting = $this->settings_model
+                    ->query()
+                    ->where('name', $setting['name'])
+                    ->get()
+                    ->row_array();
+
+                if (!empty($existing_setting)) {
+                    $setting['id'] = $existing_setting['id'];
+                }
+
+                $this->settings_model->save($setting);
+            }
+
+            response();
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Installation.php

@@ -0,0 +1,140 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.1.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Installation controller.
+ *
+ * Handles the installation related operations.
+ *
+ * @package Controllers
+ */
+class Installation extends EA_Controller
+{
+    /**
+     * Installation constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('admins_model');
+        $this->load->model('settings_model');
+        $this->load->model('services_model');
+        $this->load->model('providers_model');
+        $this->load->model('customers_model');
+
+        $this->load->library('instance');
+    }
+
+    /**
+     * Display the installation page.
+     */
+    public function index(): void
+    {
+        if (is_app_installed()) {
+            redirect();
+            return;
+        }
+
+        $this->load->view('pages/installation', [
+            'base_url' => config('base_url'),
+        ]);
+    }
+
+    /**
+     * Installs Easy!Appointments on the server.
+     */
+    public function perform(): void
+    {
+        try {
+            if (is_app_installed()) {
+                return;
+            }
+
+            $admin = request('admin');
+            $company = request('company');
+
+            $this->instance->migrate();
+
+            // Insert admin
+            $admin['timezone'] = date_default_timezone_get();
+            $admin['settings']['username'] = $admin['username'];
+            $admin['settings']['password'] = $admin['password'];
+            $admin['settings']['notifications'] = true;
+            $admin['settings']['calendar_view'] = CALENDAR_VIEW_DEFAULT;
+            unset($admin['username'], $admin['password']);
+            $admin['id'] = $this->admins_model->save($admin);
+
+            session([
+                'user_id' => $admin['id'],
+                'user_email' => $admin['email'],
+                'role_slug' => DB_SLUG_ADMIN,
+                'language' => $admin['language'],
+                'timezone' => $admin['timezone'],
+                'username' => $admin['settings']['username'],
+            ]);
+
+            // Save company settings
+            setting([
+                'company_name' => $company['company_name'],
+                'company_email' => $company['company_email'],
+                'company_link' => $company['company_link'],
+            ]);
+
+            // Service
+            $service_id = $this->services_model->save([
+                'name' => 'Service',
+                'duration' => '30',
+                'price' => '0',
+                'currency' => '',
+                'availabilities_type' => 'flexible',
+                'attendants_number' => '1',
+            ]);
+
+            // Provider
+            $this->providers_model->save([
+                'first_name' => 'Jane',
+                'last_name' => 'Doe',
+                'email' => 'jane@example.org',
+                'phone_number' => '+1 (000) 000-0000',
+                'services' => [$service_id],
+                'language' => $admin['language'],
+                'timezone' => $admin['timezone'],
+                'settings' => [
+                    'username' => 'janedoe',
+                    'password' => random_string(),
+                    'working_plan' => setting('company_working_plan'),
+                    'notifications' => true,
+                    'google_sync' => false,
+                    'sync_past_days' => 30,
+                    'sync_future_days' => 90,
+                    'calendar_view' => CALENDAR_VIEW_DEFAULT,
+                ],
+            ]);
+
+            // Customer
+            $this->customers_model->save([
+                'first_name' => 'James',
+                'last_name' => 'Doe',
+                'email' => 'james@example.org',
+                'phone_number' => '+1 (000) 000-0000',
+            ]);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Integrations.php

@@ -0,0 +1,74 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Integrations controller.
+ *
+ * Displays the integrations page.
+ *
+ * @package Controllers
+ */
+class Integrations extends EA_Controller
+{
+    /**
+     * Integrations constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('appointments_model');
+        $this->load->model('customers_model');
+        $this->load->model('services_model');
+        $this->load->model('providers_model');
+        $this->load->model('roles_model');
+        $this->load->model('settings_model');
+
+        $this->load->library('accounts');
+        $this->load->library('google_sync');
+        $this->load->library('notifications');
+        $this->load->library('synchronization');
+        $this->load->library('timezones');
+    }
+
+    /**
+     * Render the settings page.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('about')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_SYSTEM_SETTINGS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        html_vars([
+            'page_title' => lang('integrations'),
+            'active_menu' => PRIV_SYSTEM_SETTINGS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+            'privileges' => $this->roles_model->get_permissions_by_slug($role_slug),
+        ]);
+
+        $this->load->view('pages/integrations');
+    }
+}

application/controllers/Ldap_settings.php

@@ -0,0 +1,132 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * LDAP settings controller.
+ *
+ * Handles LDAP settings related operations.
+ *
+ * @package Controllers
+ */
+class Ldap_settings extends EA_Controller
+{
+    /**
+     * Ldap_settings constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('settings_model');
+
+        $this->load->library('accounts');
+        $this->load->library('ldap_client');
+    }
+
+    /**
+     * Render the settings page.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('ldap_settings')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_SYSTEM_SETTINGS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'ldap_settings' => $this->settings_model->get('name like "ldap_%"'),
+            'ldap_default_filter' => LDAP_DEFAULT_FILTER,
+            'ldap_default_field_mapping' => LDAP_DEFAULT_FIELD_MAPPING,
+        ]);
+
+        html_vars([
+            'page_title' => lang('ldap'),
+            'active_menu' => PRIV_SYSTEM_SETTINGS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+            'roles' => $this->roles_model->get(),
+        ]);
+
+        $this->load->view('pages/ldap_settings');
+    }
+
+    /**
+     * Save general settings.
+     */
+    public function save(): void
+    {
+        try {
+            if (cannot('edit', PRIV_SYSTEM_SETTINGS)) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $settings = request('ldap_settings', []);
+
+            foreach ($settings as $setting) {
+                $existing_setting = $this->settings_model
+                    ->query()
+                    ->where('name', $setting['name'])
+                    ->get()
+                    ->row_array();
+
+                if (!empty($existing_setting)) {
+                    $setting['id'] = $existing_setting['id'];
+                }
+
+                $this->settings_model->save($setting);
+            }
+
+            response();
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Search the LDAP directory.
+     *
+     * @return void
+     */
+    public function search(): void
+    {
+        try {
+            if (cannot('edit', PRIV_SYSTEM_SETTINGS)) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            if (!extension_loaded('ldap')) {
+                throw new RuntimeException('The LDAP extension is not loaded.');
+            }
+
+            $keyword = request('keyword');
+
+            $entries = $this->ldap_client->search($keyword);
+
+            json_response($entries);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Legal_settings.php

@@ -0,0 +1,102 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Client form controller.
+ *
+ * Handles legal contents settings related operations.
+ *
+ * @package Controllers
+ */
+class Legal_settings extends EA_Controller
+{
+    /**
+     * Legal_contents constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('settings_model');
+
+        $this->load->library('accounts');
+    }
+
+    /**
+     * Render the settings page.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('legal_settings')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_SYSTEM_SETTINGS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'legal_settings' => $this->settings_model->get(),
+        ]);
+
+        html_vars([
+            'page_title' => lang('settings'),
+            'active_menu' => PRIV_SYSTEM_SETTINGS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+        ]);
+
+        $this->load->view('pages/legal_settings');
+    }
+
+    /**
+     * Save legal settings.
+     */
+    public function save(): void
+    {
+        try {
+            if (cannot('edit', PRIV_SYSTEM_SETTINGS)) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $settings = request('legal_settings', []);
+
+            foreach ($settings as $setting) {
+                $existing_setting = $this->settings_model
+                    ->query()
+                    ->where('name', $setting['name'])
+                    ->get()
+                    ->row_array();
+
+                if (!empty($existing_setting)) {
+                    $setting['id'] = $existing_setting['id'];
+                }
+
+                $this->settings_model->save($setting);
+            }
+
+            response();
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Localization.php

@@ -0,0 +1,55 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Open Source Web Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) 2013 - 2020, Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.4.3
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Localization Controller
+ *
+ * Contains all the localization related methods.
+ *
+ * @package Controllers
+ */
+class Localization extends EA_Controller
+{
+    /**
+     * Change system language for current user.
+     *
+     * The language setting is stored in session data and retrieved every time the user visits any of the system pages.
+     *
+     * Notice: This method used to be in the Backend_api.php.
+     */
+    public function change_language(): void
+    {
+        try {
+            // Check if language exists in the available languages.
+            $language = request('language');
+
+            if (!in_array($language, config('available_languages'))) {
+                throw new RuntimeException(
+                    'Translations for the given language does not exist (' . request('language') . ').',
+                );
+            }
+
+            $language = request('language');
+
+            session(['language' => $language]);
+
+            config(['language' => $language]);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Login.php

@@ -0,0 +1,98 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Login controller.
+ *
+ * Handles the login page functionality.
+ *
+ * @package Controllers
+ */
+class Login extends EA_Controller
+{
+    /**
+     * Login constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('accounts');
+        $this->load->library('ldap_client');
+        $this->load->library('email_messages');
+
+        script_vars([
+            'dest_url' => session('dest_url', site_url('calendar')),
+        ]);
+    }
+
+    /**
+     * Render the login page.
+     */
+    public function index(): void
+    {
+        if (session('user_id')) {
+            redirect('calendar');
+            return;
+        }
+
+        html_vars([
+            'page_title' => lang('login'),
+            'base_url' => config('base_url'),
+            'dest_url' => session('dest_url', site_url('calendar')),
+            'company_name' => setting('company_name'),
+        ]);
+
+        $this->load->view('pages/login');
+    }
+
+    /**
+     * Validate the provided credentials and start a new session if the validation was successful.
+     */
+    public function validate(): void
+    {
+        try {
+            $username = request('username');
+
+            if (empty($username)) {
+                throw new InvalidArgumentException('No username value provided.');
+            }
+
+            $password = request('password');
+
+            if (empty($password)) {
+                throw new InvalidArgumentException('No password value provided.');
+            }
+
+            $user_data = $this->accounts->check_login($username, $password);
+
+            if (empty($user_data)) {
+                $user_data = $this->ldap_client->check_login($username, $password);
+            }
+
+            if (empty($user_data)) {
+                throw new InvalidArgumentException(lang('invalid_credentials_provided'));
+            }
+
+            $this->session->sess_regenerate();
+
+            session($user_data); // Save data in the session.
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Logout.php

@@ -0,0 +1,39 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Logout controller.
+ *
+ * Handles the logout page functionality.
+ *
+ * @package Controllers
+ */
+class Logout extends EA_Controller
+{
+    /**
+     * Render the logout page.
+     */
+    public function index(): void
+    {
+        $this->session->sess_destroy();
+
+        $company_name = setting('company_name');
+
+        html_vars([
+            'page_title' => lang('log_out'),
+            'company_name' => $company_name,
+        ]);
+
+        $this->load->view('pages/logout');
+    }
+}

application/controllers/Matomo_analytics_settings.php

@@ -0,0 +1,102 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Matomo Analytics settings controller.
+ *
+ * Handles Matomo Analytics settings related operations.
+ *
+ * @package Controllers
+ */
+class Matomo_analytics_settings extends EA_Controller
+{
+    /**
+     * Matomo_analytics_settings constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('settings_model');
+
+        $this->load->library('accounts');
+    }
+
+    /**
+     * Render the settings page.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('matomo_analytics_settings')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_SYSTEM_SETTINGS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'matomo_analytics_settings' => $this->settings_model->get('name like "matomo_analytics_%"'),
+        ]);
+
+        html_vars([
+            'page_title' => lang('matomo_analytics'),
+            'active_menu' => PRIV_SYSTEM_SETTINGS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+        ]);
+
+        $this->load->view('pages/matomo_analytics_settings');
+    }
+
+    /**
+     * Save general settings.
+     */
+    public function save(): void
+    {
+        try {
+            if (cannot('edit', PRIV_SYSTEM_SETTINGS)) {
+                throw new RuntimeException('You do not have the required permissions for this task.');
+            }
+
+            $settings = request('matomo_analytics_settings', []);
+
+            foreach ($settings as $setting) {
+                $existing_setting = $this->settings_model
+                    ->query()
+                    ->where('name', $setting['name'])
+                    ->get()
+                    ->row_array();
+
+                if (!empty($existing_setting)) {
+                    $setting['id'] = $existing_setting['id'];
+                }
+
+                $this->settings_model->save($setting);
+            }
+
+            response();
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Privacy.php

@@ -0,0 +1,70 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.3.2
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Privacy controller.
+ *
+ * Handles the privacy related operations.
+ *
+ * @package Controllers
+ */
+class Privacy extends EA_Controller
+{
+    /**
+     * Privacy constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->driver('cache', ['adapter' => 'file']);
+
+        $this->load->model('customers_model');
+    }
+
+    /**
+     * Remove all customer data (including appointments) from the system.
+     */
+    public function delete_personal_information(): void
+    {
+        try {
+            $display_delete_personal_information = setting('display_delete_personal_information');
+
+            if (!$display_delete_personal_information) {
+                abort(403, 'Forbidden');
+            }
+
+            $customer_token = request('customer_token');
+
+            if (empty($customer_token)) {
+                throw new InvalidArgumentException('Invalid customer token value provided.');
+            }
+
+            $customer_id = $this->cache->get('customer-token-' . $customer_token);
+
+            if (empty($customer_id)) {
+                throw new InvalidArgumentException(
+                    'Customer ID does not exist, please reload the page ' . 'and try again.',
+                );
+            }
+
+            $this->customers_model->delete($customer_id);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Providers.php

@@ -0,0 +1,279 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Providers controller.
+ *
+ * Handles the providers related operations.
+ *
+ * @package Controllers
+ */
+class Providers extends EA_Controller
+{
+    public array $allowed_provider_fields = [
+        'id',
+        'first_name',
+        'last_name',
+        'email',
+        'alt_number',
+        'phone_number',
+        'address',
+        'city',
+        'state',
+        'zip_code',
+        'notes',
+        'timezone',
+        'language',
+        'is_private',
+        'ldap_dn',
+        'id_roles',
+        'settings',
+        'services',
+    ];
+
+    public array $optional_provider_fields = [
+        'services' => [],
+    ];
+
+    public array $allowed_provider_setting_fields = [
+        'username',
+        'password',
+        'working_plan',
+        'working_plan_exceptions',
+        'notifications',
+        'calendar_view',
+    ];
+
+    public array $optional_provider_setting_fields = [
+        'working_plan' => null,
+        'working_plan_exceptions' => '{}',
+    ];
+
+    public array $allowed_service_fields = ['id', 'name'];
+
+    /**
+     * Providers constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('providers_model');
+        $this->load->model('services_model');
+        $this->load->model('roles_model');
+
+        $this->load->library('accounts');
+        $this->load->library('timezones');
+        $this->load->library('webhooks_client');
+
+        $this->optional_provider_setting_fields['working_plan'] = setting('company_working_plan');
+    }
+
+    /**
+     * Render the backend providers page.
+     *
+     * On this page admin users will be able to manage providers, which are eventually selected by customers during the
+     * booking process.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('providers')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_USERS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        $services = $this->services_model->get();
+
+        foreach ($services as &$service) {
+            $this->services_model->only($service, $this->allowed_service_fields);
+        }
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'company_working_plan' => setting('company_working_plan'),
+            'date_format' => setting('date_format'),
+            'time_format' => setting('time_format'),
+            'first_weekday' => setting('first_weekday'),
+            'min_password_length' => MIN_PASSWORD_LENGTH,
+            'timezones' => $this->timezones->to_array(),
+            'services' => $services,
+            'default_language' => setting('default_language'),
+            'default_timezone' => setting('default_timezone'),
+        ]);
+
+        html_vars([
+            'page_title' => lang('providers'),
+            'active_menu' => PRIV_USERS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+            'grouped_timezones' => $this->timezones->to_grouped_array(),
+            'privileges' => $this->roles_model->get_permissions_by_slug($role_slug),
+            'services' => $this->services_model->get(),
+        ]);
+
+        $this->load->view('pages/providers');
+    }
+
+    /**
+     * Filter providers by the provided keyword.
+     */
+    public function search(): void
+    {
+        try {
+            if (cannot('view', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $keyword = request('keyword', '');
+
+            $order_by = request('order_by', 'update_datetime DESC');
+
+            $limit = request('limit', 1000);
+
+            $offset = (int) request('offset', '0');
+
+            $providers = $this->providers_model->search($keyword, $limit, $offset, $order_by);
+
+            json_response($providers);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new provider.
+     */
+    public function store(): void
+    {
+        try {
+            if (cannot('add', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $provider = request('provider');
+
+            $this->providers_model->only($provider, $this->allowed_provider_fields);
+
+            $this->providers_model->only($provider['settings'], $this->allowed_provider_setting_fields);
+
+            $this->providers_model->optional($provider, $this->optional_provider_fields);
+
+            $this->providers_model->optional($provider['settings'], $this->optional_provider_setting_fields);
+
+            $provider_id = $this->providers_model->save($provider);
+
+            $provider = $this->providers_model->find($provider_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_PROVIDER_SAVE, $provider);
+
+            json_response([
+                'success' => true,
+                'id' => $provider_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Find a provider.
+     */
+    public function find(): void
+    {
+        try {
+            if (cannot('view', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $provider_id = request('provider_id');
+
+            $provider = $this->providers_model->find($provider_id);
+
+            json_response($provider);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a provider.
+     */
+    public function update(): void
+    {
+        try {
+            if (cannot('edit', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $provider = request('provider');
+
+            $this->providers_model->only($provider, $this->allowed_provider_fields);
+
+            $this->providers_model->only($provider['settings'], $this->allowed_provider_setting_fields);
+
+            $this->providers_model->optional($provider, $this->optional_provider_fields);
+
+            $this->providers_model->optional($provider['settings'], $this->optional_provider_setting_fields);
+
+            $provider_id = $this->providers_model->save($provider);
+
+            $provider = $this->providers_model->find($provider_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_PROVIDER_SAVE, $provider);
+
+            json_response([
+                'success' => true,
+                'id' => $provider_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Remove a provider.
+     */
+    public function destroy(): void
+    {
+        try {
+            if (cannot('delete', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $provider_id = request('provider_id');
+
+            $provider = $this->providers_model->find($provider_id);
+
+            $this->providers_model->delete($provider_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_PROVIDER_DELETE, $provider);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Recovery.php

@@ -0,0 +1,90 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Recovery controller.
+ *
+ * Handles the recovery page functionality.
+ *
+ * @package Controllers
+ */
+class Recovery extends EA_Controller
+{
+    /**
+     * User constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('accounts');
+        $this->load->library('email_messages');
+    }
+
+    /**
+     * Display the password recovery page.
+     */
+    public function index(): void
+    {
+        $company_name = setting('company_name');
+
+        html_vars([
+            'page_title' => lang('forgot_your_password'),
+            'dest_url' => session('dest_url', site_url('backend')),
+            'company_name' => $company_name,
+        ]);
+
+        $this->load->view('pages/recovery');
+    }
+
+    /**
+     * Recover the user password and notify the user via email.
+     */
+    public function perform(): void
+    {
+        try {
+            $username = request('username');
+
+            if (empty($username)) {
+                throw new InvalidArgumentException('No username value provided.');
+            }
+
+            $email = request('email');
+
+            if (empty($email)) {
+                throw new InvalidArgumentException('No email value provided.');
+            }
+
+            $new_password = $this->accounts->regenerate_password($username, $email);
+
+            $company_color = setting('company_color');
+
+            if ($new_password) {
+                $settings = [
+                    'company_name' => setting('company_name'),
+                    'company_link' => setting('company_link'),
+                    'company_email' => setting('company_email'),
+                    'company_color' => !empty($company_color) && $company_color != DEFAULT_COMPANY_COLOR ? $company_color : null,
+                ];
+
+                $this->email_messages->send_password($new_password, $email, $settings);
+            }
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Secretaries.php

@@ -0,0 +1,254 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Secretaries controller.
+ *
+ * Handles the secretaries related operations.
+ *
+ * @package Controllers
+ */
+class Secretaries extends EA_Controller
+{
+    public array $allowed_provider_fields = ['id', 'first_name', 'last_name'];
+    public array $allowed_secretary_fields = [
+        'id',
+        'first_name',
+        'last_name',
+        'email',
+        'alt_number',
+        'phone_number',
+        'address',
+        'city',
+        'state',
+        'zip_code',
+        'notes',
+        'timezone',
+        'language',
+        'is_private',
+        'ldap_dn',
+        'id_roles',
+        'settings',
+        'providers',
+    ];
+    public array $allowed_secretary_setting_fields = ['username', 'password', 'notifications', 'calendar_view'];
+    public array $optional_secretary_fields = [
+        'providers' => [],
+    ];
+
+    /**
+     * Secretaries constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('secretaries_model');
+        $this->load->model('providers_model');
+        $this->load->model('roles_model');
+
+        $this->load->library('accounts');
+        $this->load->library('timezones');
+        $this->load->library('webhooks_client');
+    }
+
+    /**
+     * Render the backend secretaries page.
+     *
+     * On this page secretary users will be able to manage secretaries, which are eventually selected by customers during the
+     * booking process.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('secretaries')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_USERS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        $providers = $this->providers_model->get();
+
+        foreach ($providers as &$provider) {
+            $this->providers_model->only($provider, $this->allowed_provider_fields);
+        }
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'timezones' => $this->timezones->to_array(),
+            'min_password_length' => MIN_PASSWORD_LENGTH,
+            'providers' => $providers,
+            'default_language' => setting('default_language'),
+            'default_timezone' => setting('default_timezone'),
+        ]);
+
+        html_vars([
+            'page_title' => lang('secretaries'),
+            'active_menu' => PRIV_USERS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+            'grouped_timezones' => $this->timezones->to_grouped_array(),
+            'privileges' => $this->roles_model->get_permissions_by_slug($role_slug),
+            'providers' => $this->providers_model->get(),
+        ]);
+
+        $this->load->view('pages/secretaries');
+    }
+
+    /**
+     * Filter secretaries by the provided keyword.
+     */
+    public function search(): void
+    {
+        try {
+            if (cannot('view', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $keyword = request('keyword', '');
+
+            $order_by = request('order_by', 'update_datetime DESC');
+
+            $limit = request('limit', 1000);
+
+            $offset = (int) request('offset', '0');
+
+            $secretaries = $this->secretaries_model->search($keyword, $limit, $offset, $order_by);
+
+            json_response($secretaries);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new secretary.
+     */
+    public function store(): void
+    {
+        try {
+            if (cannot('add', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $secretary = request('secretary');
+
+            $this->secretaries_model->only($secretary, $this->allowed_secretary_fields);
+
+            $this->secretaries_model->only($secretary['settings'], $this->allowed_secretary_setting_fields);
+
+            $this->secretaries_model->optional($secretary, $this->optional_secretary_fields);
+
+            $secretary_id = $this->secretaries_model->save($secretary);
+
+            $secretary = $this->secretaries_model->find($secretary_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_SECRETARY_SAVE, $secretary);
+
+            json_response([
+                'success' => true,
+                'id' => $secretary_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Find a secretary.
+     */
+    public function find(): void
+    {
+        try {
+            if (cannot('view', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $secretary_id = request('secretary_id');
+
+            $secretary = $this->secretaries_model->find($secretary_id);
+
+            json_response($secretary);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a secretary.
+     */
+    public function update(): void
+    {
+        try {
+            if (cannot('edit', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $secretary = request('secretary');
+
+            $this->secretaries_model->only($secretary, $this->allowed_secretary_fields);
+
+            $this->secretaries_model->only($secretary['settings'], $this->allowed_secretary_setting_fields);
+
+            $this->secretaries_model->optional($secretary, $this->optional_secretary_fields);
+
+            $secretary_id = $this->secretaries_model->save($secretary);
+
+            $secretary = $this->secretaries_model->find($secretary_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_SECRETARY_SAVE, $secretary);
+
+            json_response([
+                'success' => true,
+                'id' => $secretary_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Remove a secretary.
+     */
+    public function destroy(): void
+    {
+        try {
+            if (cannot('delete', PRIV_USERS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $secretary_id = request('secretary_id');
+
+            $secretary = $this->secretaries_model->find($secretary_id);
+
+            $this->secretaries_model->delete($secretary_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_SECRETARY_DELETE, $secretary);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Service_categories.php

@@ -0,0 +1,215 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Service-categories controller.
+ *
+ * Handles the service-categories related operations.
+ *
+ * @package Controllers
+ */
+class Service_categories extends EA_Controller
+{
+    public array $allowed_service_category_fields = ['id', 'name', 'description'];
+
+    public array $optional_service_category_fields = [];
+
+    /**
+     * Service-categories constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('service_categories_model');
+        $this->load->model('roles_model');
+
+        $this->load->library('accounts');
+        $this->load->library('timezones');
+        $this->load->library('webhooks_client');
+    }
+
+    /**
+     * Render the backend service-categories page.
+     *
+     * On this page admin users will be able to manage service-categories, which are eventually selected by customers during the
+     * booking process.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('service_categories')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_SERVICES)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+        ]);
+
+        html_vars([
+            'page_title' => lang('service_categories'),
+            'active_menu' => PRIV_SERVICES,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+            'timezones' => $this->timezones->to_array(),
+            'privileges' => $this->roles_model->get_permissions_by_slug($role_slug),
+        ]);
+
+        $this->load->view('pages/service_categories');
+    }
+
+    /**
+     * Filter service-categories by the provided keyword.
+     */
+    public function search(): void
+    {
+        try {
+            if (cannot('view', PRIV_SERVICES)) {
+                abort(403, 'Forbidden');
+            }
+
+            $keyword = request('keyword', '');
+
+            $order_by = request('order_by', 'update_datetime DESC');
+
+            $limit = request('limit', 1000);
+
+            $offset = (int) request('offset', '0');
+
+            $service_categories = $this->service_categories_model->search($keyword, $limit, $offset, $order_by);
+
+            json_response($service_categories);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new service-category.
+     */
+    public function store(): void
+    {
+        try {
+            if (cannot('add', PRIV_SERVICES)) {
+                abort(403, 'Forbidden');
+            }
+
+            $service_category = request('service_category');
+
+            $this->service_categories_model->only($service_category, $this->allowed_service_category_fields);
+
+            $this->service_categories_model->optional($service_category, $this->optional_service_category_fields);
+
+            $service_category_id = $this->service_categories_model->save($service_category);
+
+            $service_category = $this->service_categories_model->find($service_category_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_SERVICE_CATEGORY_SAVE, $service_category);
+
+            json_response([
+                'success' => true,
+                'id' => $service_category_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Find a service-category.
+     */
+    public function find(): void
+    {
+        try {
+            if (cannot('view', PRIV_SERVICES)) {
+                abort(403, 'Forbidden');
+            }
+
+            $service_category_id = request('service_category_id');
+
+            $service_category = $this->service_categories_model->find($service_category_id);
+
+            json_response($service_category);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a service-category.
+     */
+    public function update(): void
+    {
+        try {
+            if (cannot('edit', PRIV_SERVICES)) {
+                abort(403, 'Forbidden');
+            }
+
+            $service_category = request('service_category');
+
+            $this->service_categories_model->only($service_category, $this->allowed_service_category_fields);
+
+            $this->service_categories_model->optional($service_category, $this->optional_service_category_fields);
+
+            $service_category_id = $this->service_categories_model->save($service_category);
+
+            $service_category = $this->service_categories_model->find($service_category_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_SERVICE_CATEGORY_SAVE, $service_category);
+
+            json_response([
+                'success' => true,
+                'id' => $service_category_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Remove a service-category.
+     */
+    public function destroy(): void
+    {
+        try {
+            if (cannot('delete', PRIV_SERVICES)) {
+                abort(403, 'Forbidden');
+            }
+
+            $service_category_id = request('service_category_id');
+
+            $service_category = $this->service_categories_model->find($service_category_id);
+
+            $this->service_categories_model->delete($service_category_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_SERVICE_CATEGORY_DELETE, $service_category);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Services.php

@@ -0,0 +1,230 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Services controller.
+ *
+ * Handles the services related operations.
+ *
+ * @package Controllers
+ */
+class Services extends EA_Controller
+{
+    public array $allowed_service_fields = [
+        'id',
+        'name',
+        'duration',
+        'price',
+        'currency',
+        'description',
+        'color',
+        'location',
+        'availabilities_type',
+        'attendants_number',
+        'is_private',
+        'id_service_categories',
+    ];
+    public array $optional_service_fields = [
+        'id_service_categories' => null,
+    ];
+
+    /**
+     * Services constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('services_model');
+        $this->load->model('roles_model');
+
+        $this->load->library('accounts');
+        $this->load->library('timezones');
+        $this->load->library('webhooks_client');
+    }
+
+    /**
+     * Render the backend services page.
+     *
+     * On this page admin users will be able to manage services, which are eventually selected by customers during the
+     * booking process.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('services')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_SERVICES)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+            'event_minimum_duration' => EVENT_MINIMUM_DURATION,
+        ]);
+
+        html_vars([
+            'page_title' => lang('services'),
+            'active_menu' => PRIV_SERVICES,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+            'timezones' => $this->timezones->to_array(),
+            'privileges' => $this->roles_model->get_permissions_by_slug($role_slug),
+        ]);
+
+        $this->load->view('pages/services');
+    }
+
+    /**
+     * Filter services by the provided keyword.
+     */
+    public function search(): void
+    {
+        try {
+            if (cannot('view', PRIV_SERVICES)) {
+                abort(403, 'Forbidden');
+            }
+
+            $keyword = request('keyword', '');
+
+            $order_by = request('order_by', 'update_datetime DESC');
+
+            $limit = request('limit', 1000);
+
+            $offset = (int) request('offset', '0');
+
+            $services = $this->services_model->search($keyword, $limit, $offset, $order_by);
+
+            json_response($services);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new service.
+     */
+    public function store(): void
+    {
+        try {
+            if (cannot('add', PRIV_SERVICES)) {
+                abort(403, 'Forbidden');
+            }
+
+            $service = request('service');
+
+            $this->services_model->only($service, $this->allowed_service_fields);
+
+            $this->services_model->optional($service, $this->optional_service_fields);
+
+            $service_id = $this->services_model->save($service);
+
+            $service = $this->services_model->find($service_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_SERVICE_SAVE, $service);
+
+            json_response([
+                'success' => true,
+                'id' => $service_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Find a service.
+     */
+    public function find(): void
+    {
+        try {
+            if (cannot('delete', PRIV_SERVICES)) {
+                abort(403, 'Forbidden');
+            }
+
+            $service_id = request('service_id');
+
+            $service = $this->services_model->find($service_id);
+
+            json_response($service);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a service.
+     */
+    public function update(): void
+    {
+        try {
+            if (cannot('edit', PRIV_SERVICES)) {
+                abort(403, 'Forbidden');
+            }
+
+            $service = request('service');
+
+            $this->services_model->only($service, $this->allowed_service_fields);
+
+            $this->services_model->optional($service, $this->optional_service_fields);
+
+            $service_id = $this->services_model->save($service);
+
+            $service = $this->services_model->find($service_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_SERVICE_SAVE, $service);
+
+            json_response([
+                'success' => true,
+                'id' => $service_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Remove a service.
+     */
+    public function destroy(): void
+    {
+        try {
+            if (cannot('delete', PRIV_SERVICES)) {
+                abort(403, 'Forbidden');
+            }
+
+            $service_id = request('service_id');
+
+            $service = $this->services_model->find($service_id);
+
+            $this->services_model->delete($service_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_SERVICE_DELETE, $service);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Test.php

@@ -0,0 +1,39 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/*
+ * This file can only be used in a testing environment and only from the terminal.
+ */
+
+if (ENVIRONMENT !== 'testing' || !is_cli()) {
+    show_404();
+}
+
+/**
+ * Test controller.
+ *
+ * This controller does not have or need any logic, it is just used so that CI can be loaded properly during the test
+ * execution.
+ */
+class Test extends EA_Controller
+{
+    /**
+     * Placeholder callback.
+     *
+     * @return void
+     */
+    public function index(): void
+    {
+        //
+    }
+}

application/controllers/Unavailabilities.php

@@ -0,0 +1,193 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Unavailabilities controller.
+ *
+ * Handles the unavailabilities related operations.
+ *
+ * @package Controllers
+ */
+class Unavailabilities extends EA_Controller
+{
+    public array $allowed_unavailability_fields = [
+        'id',
+        'start_datetime',
+        'end_datetime',
+        'location',
+        'notes',
+        'is_unavailability',
+        'id_users_provider',
+    ];
+
+    public array $optional_unavailability_fields = [
+        //
+    ];
+
+    /**
+     * Unavailabilities constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('unavailabilities_model');
+        $this->load->model('roles_model');
+
+        $this->load->library('accounts');
+        $this->load->library('timezones');
+        $this->load->library('webhooks_client');
+    }
+
+    /**
+     * Filter unavailabilities by the provided keyword.
+     */
+    public function search(): void
+    {
+        try {
+            if (cannot('view', PRIV_APPOINTMENTS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $keyword = request('keyword', '');
+
+            $order_by = request('order_by', 'update_datetime DESC');
+
+            $limit = request('limit', 1000);
+
+            $offset = (int) request('offset', '0');
+
+            $unavailabilities = $this->unavailabilities_model->search($keyword, $limit, $offset, $order_by);
+
+            json_response($unavailabilities);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new unavailability.
+     */
+    public function store(): void
+    {
+        try {
+            if (cannot('add', PRIV_APPOINTMENTS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $unavailability = request('unavailability');
+
+            $this->unavailabilities_model->only($unavailability, $this->allowed_unavailability_fields);
+
+            $this->unavailabilities_model->optional($unavailability, $this->optional_unavailability_fields);
+
+            $unavailability_id = $this->unavailabilities_model->save($unavailability);
+
+            $unavailability = $this->unavailabilities_model->find($unavailability_id);
+
+            $provider = $this->providers_model->find($unavailability['id_users_provider']);
+
+            $this->synchronization->sync_unavailability_saved($unavailability, $provider);
+
+            $this->webhooks_client->trigger(WEBHOOK_UNAVAILABILITY_SAVE, $unavailability);
+
+            json_response([
+                'success' => true,
+                'id' => $unavailability_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Find an unavailability.
+     */
+    public function find(): void
+    {
+        try {
+            if (cannot('view', PRIV_APPOINTMENTS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $unavailability_id = request('unavailability_id');
+
+            $unavailability = $this->unavailabilities_model->find($unavailability_id);
+
+            json_response($unavailability);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a unavailability.
+     */
+    public function update(): void
+    {
+        try {
+            if (cannot('edit', PRIV_APPOINTMENTS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $unavailability = request('unavailability');
+
+            $this->unavailabilities_model->only($unavailability, $this->allowed_unavailability_fields);
+
+            $this->unavailabilities_model->optional($unavailability, $this->optional_unavailability_fields);
+
+            $unavailability_id = $this->unavailabilities_model->save($unavailability);
+
+            $unavailability = $this->unavailabilities_model->find($unavailability_id);
+
+            $provider = $this->providers_model->find($unavailability['id_users_provider']);
+
+            $this->synchronization->sync_unavailability_saved($unavailability, $provider);
+
+            $this->webhooks_client->trigger(WEBHOOK_UNAVAILABILITY_SAVE, $unavailability);
+
+            json_response([
+                'success' => true,
+                'id' => $unavailability_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Remove a unavailability.
+     */
+    public function destroy(): void
+    {
+        try {
+            if (cannot('delete', PRIV_APPOINTMENTS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $unavailability_id = request('unavailability_id');
+
+            $unavailability = $this->unavailabilities_model->find($unavailability_id);
+
+            $this->unavailabilities_model->delete($unavailability_id);
+
+            $this->webhooks_client->trigger(WEBHOOK_UNAVAILABILITY_DELETE, $unavailability);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/Update.php

@@ -0,0 +1,74 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.1.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Update controller.
+ *
+ * Handles the update related operations.
+ *
+ * @package Controllers
+ */
+class Update extends EA_Controller
+{
+    /**
+     * Update constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('admins_model');
+        $this->load->model('settings_model');
+        $this->load->model('services_model');
+        $this->load->model('providers_model');
+        $this->load->model('customers_model');
+
+        $this->load->library('instance');
+    }
+
+    /**
+     * This method will update the instance to the latest available version in the server.
+     *
+     * IMPORTANT: The code files must exist in the server, this method will not fetch any new files but will update
+     * the database schema.
+     *
+     * This method can be used either by loading the page in the browser or by an ajax request. But it will answer with
+     * JSON encoded data.
+     */
+    public function index(): void
+    {
+        try {
+            $user_id = session('user_id');
+
+            if (cannot('edit', PRIV_SYSTEM_SETTINGS)) {
+                if ($user_id) {
+                    abort(403, 'Forbidden');
+                }
+
+                redirect('login');
+
+                return;
+            }
+
+            $this->instance->migrate();
+
+            $view = ['success' => true];
+        } catch (Throwable $e) {
+            $view = ['success' => false, 'exception' => $e->getMessage()];
+        }
+
+        html_vars($view);
+
+        $this->load->view('pages/update');
+    }
+}

application/controllers/User.php

@@ -0,0 +1,71 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * User controller.
+ *
+ * Handles the user related operations.
+ *
+ * @package Controllers
+ */
+class User extends EA_Controller
+{
+    /**
+     * User constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('accounts');
+        $this->load->library('email_messages');
+    }
+
+    /**
+     * Redirect to the login page.
+     */
+    public function index(): void
+    {
+        redirect('login');
+    }
+
+    /**
+     * Display the login page.
+     *
+     * @deprecated Since 1.5 Use the Login controller instead.
+     */
+    public function login(): void
+    {
+        redirect('login');
+    }
+
+    /**
+     * Display the logout page.
+     *
+     * @deprecated Since 1.5 Use the Logout controller instead.
+     */
+    public function logout(): void
+    {
+        redirect('logout');
+    }
+
+    /**
+     * Display the password recovery page.
+     *
+     * @deprecated Since 1.5 Use the Logout controller instead.
+     */
+    public function forgot_password(): void
+    {
+        redirect('recovery');
+    }
+}

application/controllers/Webhooks.php

@@ -0,0 +1,233 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.0.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Webhooks controller.
+ *
+ * Handles the webhooks related operations.
+ *
+ * @package Controllers
+ */
+class Webhooks extends EA_Controller
+{
+    public array $allowed_webhook_fields = [
+        'id',
+        'name',
+        'url',
+        'actions',
+        'secret_header',
+        'secret_token',
+        'is_ssl_verified',
+        'notes',
+    ];
+
+    public array $optional_webhook_fields = [
+        //
+    ];
+
+    /**
+     * Webhooks constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('webhooks_model');
+        $this->load->model('roles_model');
+
+        $this->load->library('accounts');
+        $this->load->library('timezones');
+    }
+
+    /**
+     * Render the backend webhooks page.
+     *
+     * On this page admin users will be able to manage webhooks, which are eventually selected by customers during the
+     * booking process.
+     */
+    public function index(): void
+    {
+        session(['dest_url' => site_url('webhooks')]);
+
+        $user_id = session('user_id');
+
+        if (cannot('view', PRIV_WEBHOOKS)) {
+            if ($user_id) {
+                abort(403, 'Forbidden');
+            }
+
+            redirect('login');
+
+            return;
+        }
+
+        $role_slug = session('role_slug');
+
+        script_vars([
+            'user_id' => $user_id,
+            'role_slug' => $role_slug,
+        ]);
+
+        html_vars([
+            'page_title' => lang('webhooks'),
+            'active_menu' => PRIV_SYSTEM_SETTINGS,
+            'user_display_name' => $this->accounts->get_user_display_name($user_id),
+            'timezones' => $this->timezones->to_array(),
+            'privileges' => $this->roles_model->get_permissions_by_slug($role_slug),
+            'available_actions' => [
+                WEBHOOK_APPOINTMENT_SAVE,
+                WEBHOOK_APPOINTMENT_DELETE,
+                WEBHOOK_UNAVAILABILITY_SAVE,
+                WEBHOOK_UNAVAILABILITY_DELETE,
+                WEBHOOK_BLOCKED_PERIOD_SAVE,
+                WEBHOOK_BLOCKED_PERIOD_DELETE,
+                WEBHOOK_CUSTOMER_SAVE,
+                WEBHOOK_CUSTOMER_DELETE,
+                WEBHOOK_SERVICE_SAVE,
+                WEBHOOK_SERVICE_DELETE,
+                WEBHOOK_SERVICE_CATEGORY_SAVE,
+                WEBHOOK_SERVICE_CATEGORY_DELETE,
+                WEBHOOK_PROVIDER_SAVE,
+                WEBHOOK_PROVIDER_DELETE,
+                WEBHOOK_SECRETARY_SAVE,
+                WEBHOOK_SECRETARY_DELETE,
+                WEBHOOK_ADMIN_SAVE,
+                WEBHOOK_ADMIN_DELETE,
+            ],
+        ]);
+
+        $this->load->view('pages/webhooks');
+    }
+
+    /**
+     * Filter webhooks by the provided keyword.
+     */
+    public function search(): void
+    {
+        try {
+            if (cannot('view', PRIV_WEBHOOKS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $keyword = request('keyword', '');
+
+            $order_by = request('order_by', 'update_datetime DESC');
+
+            $limit = request('limit', 1000);
+
+            $offset = (int) request('offset', '0');
+
+            $webhooks = $this->webhooks_model->search($keyword, $limit, $offset, $order_by);
+
+            json_response($webhooks);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new webhook.
+     */
+    public function store(): void
+    {
+        try {
+            if (cannot('add', PRIV_WEBHOOKS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $webhook = request('webhook');
+
+            $this->webhooks_model->only($webhook, $this->allowed_webhook_fields);
+
+            $this->webhooks_model->optional($webhook, $this->optional_webhook_fields);
+
+            $webhook_id = $this->webhooks_model->save($webhook);
+
+            json_response([
+                'success' => true,
+                'id' => $webhook_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a webhook.
+     */
+    public function update(): void
+    {
+        try {
+            if (cannot('edit', PRIV_WEBHOOKS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $webhook = request('webhook');
+
+            $this->webhooks_model->only($webhook, $this->allowed_webhook_fields);
+
+            $this->webhooks_model->optional($webhook, $this->optional_webhook_fields);
+
+            $webhook_id = $this->webhooks_model->save($webhook);
+
+            json_response([
+                'success' => true,
+                'id' => $webhook_id,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Remove a webhook.
+     */
+    public function destroy(): void
+    {
+        try {
+            if (cannot('delete', PRIV_WEBHOOKS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $webhook_id = request('webhook_id');
+
+            $this->webhooks_model->delete($webhook_id);
+
+            json_response([
+                'success' => true,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Find a webhook.
+     */
+    public function find(): void
+    {
+        try {
+            if (cannot('view', PRIV_WEBHOOKS)) {
+                abort(403, 'Forbidden');
+            }
+
+            $webhook_id = request('webhook_id');
+
+            $webhook = $this->webhooks_model->find($webhook_id);
+
+            json_response($webhook);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/api/index.html

@@ -0,0 +1,10 @@
+<html lang="en">
+<head>
+    <title>403 Forbidden</title>
+</head>
+<body>
+
+<p>Directory access is forbidden.</p>
+
+</body>
+</html>

application/controllers/api/v1/Admins_api_v1.php

@@ -0,0 +1,202 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Admins API v1 controller.
+ *
+ * @package Controllers
+ */
+class Admins_api_v1 extends EA_Controller
+{
+    /**
+     * Admins_api_v1 constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('admins_model');
+
+        $this->load->library('api');
+
+        $this->api->auth();
+
+        $this->api->model('admins_model');
+    }
+
+    /**
+     * Get an admin collection.
+     */
+    public function index(): void
+    {
+        try {
+            $keyword = $this->api->request_keyword();
+
+            $limit = $this->api->request_limit();
+
+            $offset = $this->api->request_offset();
+
+            $order_by = $this->api->request_order_by();
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $admins = empty($keyword)
+                ? $this->admins_model->get(null, $limit, $offset, $order_by)
+                : $this->admins_model->search($keyword, $limit, $offset, $order_by);
+
+            foreach ($admins as &$admin) {
+                $this->admins_model->api_encode($admin);
+
+                if (!empty($fields)) {
+                    $this->admins_model->only($admin, $fields);
+                }
+
+                if (!empty($with)) {
+                    $this->admins_model->load($admin, $with);
+                }
+            }
+
+            json_response($admins);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Get a single admin.
+     *
+     * @param int|null $id Admin ID.
+     */
+    public function show(?int $id = null): void
+    {
+        try {
+            $occurrences = $this->admins_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $admin = $this->admins_model->find($id);
+
+            $this->admins_model->api_encode($admin);
+
+            if (!empty($fields)) {
+                $this->admins_model->only($admin, $fields);
+            }
+
+            if (!empty($with)) {
+                $this->admins_model->load($admin, $with);
+            }
+
+            json_response($admin);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new admin.
+     */
+    public function store(): void
+    {
+        try {
+            $admin = request();
+
+            $this->admins_model->api_decode($admin);
+
+            if (array_key_exists('id', $admin)) {
+                unset($admin['id']);
+            }
+
+            if (!array_key_exists('settings', $admin)) {
+                throw new InvalidArgumentException('No settings property provided.');
+            }
+
+            $admin_id = $this->admins_model->save($admin);
+
+            $created_admin = $this->admins_model->find($admin_id);
+
+            $this->admins_model->api_encode($created_admin);
+
+            json_response($created_admin, 201);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update an admin.
+     *
+     * @param int $id Admin ID.
+     */
+    public function update(int $id): void
+    {
+        try {
+            $occurrences = $this->admins_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $original_admin = $occurrences[0];
+
+            $admin = request();
+
+            $this->admins_model->api_decode($admin, $original_admin);
+
+            $admin_id = $this->admins_model->save($admin);
+
+            $updated_admin = $this->admins_model->find($admin_id);
+
+            $this->admins_model->api_encode($updated_admin);
+
+            json_response($updated_admin);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Delete an admin.
+     *
+     * @param int $id Admin ID.
+     */
+    public function destroy(int $id): void
+    {
+        try {
+            $occurrences = $this->admins_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $this->admins_model->delete($id);
+
+            response('', 204);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/api/v1/Appointments_api_v1.php

@@ -0,0 +1,383 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Appointments API v1 controller.
+ *
+ * @package Controllers
+ */
+class Appointments_api_v1 extends EA_Controller
+{
+    /**
+     * Appointments_api_v1 constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->model('appointments_model');
+        $this->load->model('customers_model');
+        $this->load->model('providers_model');
+        $this->load->model('services_model');
+        $this->load->model('settings_model');
+
+        $this->load->library('api');
+        $this->load->library('synchronization');
+        $this->load->library('notifications');
+
+        $this->api->auth();
+
+        $this->api->model('appointments_model');
+    }
+
+    /**
+     * Get an appointment collection.
+     */
+    public function index(): void
+    {
+        try {
+            $keyword = $this->api->request_keyword();
+
+            $limit = $this->api->request_limit();
+
+            $offset = $this->api->request_offset();
+
+            $order_by = $this->api->request_order_by();
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $where = null;
+
+            // Date query param.
+
+            $date = request('date');
+
+            if (!empty($date)) {
+                $where['DATE(start_datetime)'] = new DateTime($date)->format('Y-m-d');
+            }
+
+            // From query param.
+
+            $from = request('from');
+
+            if (!empty($from)) {
+                $where['DATE(start_datetime) >='] = new DateTime($from)->format('Y-m-d');
+            }
+
+            // Till query param.
+
+            $till = request('till');
+
+            if (!empty($till)) {
+                $where['DATE(end_datetime) <='] = new DateTime($till)->format('Y-m-d');
+            }
+
+            // Service ID query param.
+
+            $service_id = request('serviceId');
+
+            if (!empty($service_id)) {
+                $where['id_services'] = $service_id;
+            }
+
+            // Provider ID query param.
+
+            $provider_id = request('providerId');
+
+            if (!empty($provider_id)) {
+                $where['id_users_provider'] = $provider_id;
+            }
+
+            // Customer ID query param.
+
+            $customer_id = request('customerId');
+
+            if (!empty($customer_id)) {
+                $where['id_users_customer'] = $customer_id;
+            }
+
+            $appointments = empty($keyword)
+                ? $this->appointments_model->get($where, $limit, $offset, $order_by)
+                : $this->appointments_model->search($keyword, $limit, $offset, $order_by);
+
+            foreach ($appointments as &$appointment) {
+                $this->appointments_model->api_encode($appointment);
+
+                $this->aggregates($appointment);
+
+                if (!empty($fields)) {
+                    $this->appointments_model->only($appointment, $fields);
+                }
+
+                if (!empty($with)) {
+                    $this->appointments_model->load($appointment, $with);
+                }
+            }
+
+            json_response($appointments);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Load the relations of the current appointment if the "aggregates" query parameter is present.
+     *
+     * This is a compatibility addition to the appointment resource which was the only one to support it.
+     *
+     * Use the "attach" query parameter instead as this one will be removed.
+     *
+     * @param array $appointment Appointment data.
+     *
+     * @deprecated Since 1.5
+     */
+    private function aggregates(array &$appointment): void
+    {
+        $aggregates = request('aggregates') !== null;
+
+        if ($aggregates) {
+            $appointment['service'] = $this->services_model->find(
+                $appointment['id_services'] ?? ($appointment['serviceId'] ?? null),
+            );
+            $appointment['provider'] = $this->providers_model->find(
+                $appointment['id_users_provider'] ?? ($appointment['providerId'] ?? null),
+            );
+            $appointment['customer'] = $this->customers_model->find(
+                $appointment['id_users_customer'] ?? ($appointment['customerId'] ?? null),
+            );
+            $this->services_model->api_encode($appointment['service']);
+            $this->providers_model->api_encode($appointment['provider']);
+            $this->customers_model->api_encode($appointment['customer']);
+        }
+    }
+
+    /**
+     * Get a single appointment.
+     *
+     * @param int|null $id Appointment ID.
+     */
+    public function show(?int $id = null): void
+    {
+        try {
+            $occurrences = $this->appointments_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $appointment = $this->appointments_model->find($id);
+
+            $this->appointments_model->api_encode($appointment);
+
+            if (!empty($fields)) {
+                $this->appointments_model->only($appointment, $fields);
+            }
+
+            if (!empty($with)) {
+                $this->appointments_model->load($appointment, $with);
+            }
+
+            json_response($appointment);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new appointment.
+     */
+    public function store(): void
+    {
+        try {
+            $appointment = request();
+
+            $this->appointments_model->api_decode($appointment);
+
+            if (array_key_exists('id', $appointment)) {
+                unset($appointment['id']);
+            }
+
+            if (!array_key_exists('end_datetime', $appointment)) {
+                $appointment['end_datetime'] = $this->calculate_end_datetime($appointment);
+            }
+
+            $appointment_id = $this->appointments_model->save($appointment);
+
+            $created_appointment = $this->appointments_model->find($appointment_id);
+
+            $this->notify_and_sync_appointment($created_appointment);
+
+            $this->appointments_model->api_encode($created_appointment);
+
+            json_response($created_appointment, 201);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Calculate the end date time of an appointment based on the selected service.
+     *
+     * @param array $appointment Appointment data.
+     *
+     * @return string Returns the end date time value.
+     *
+     * @throws Exception
+     */
+    private function calculate_end_datetime(array $appointment): string
+    {
+        $duration = $this->services_model->value($appointment['id_services'], 'duration');
+
+        $end = new DateTime($appointment['start_datetime']);
+
+        $end->add(new DateInterval('PT' . $duration . 'M'));
+
+        return $end->format('Y-m-d H:i:s');
+    }
+
+    /**
+     * Send the required notifications and trigger syncing after saving an appointment.
+     *
+     * @param array $appointment Appointment data.
+     * @param string $action Performed action ("store" or "update").
+     */
+    private function notify_and_sync_appointment(array $appointment, string $action = 'store'): void
+    {
+        $manage_mode = $action === 'update';
+
+        $service = $this->services_model->find($appointment['id_services']);
+
+        $provider = $this->providers_model->find($appointment['id_users_provider']);
+
+        $customer = $this->customers_model->find($appointment['id_users_customer']);
+
+        $company_color = setting('company_color');
+
+        $settings = [
+            'company_name' => setting('company_name'),
+            'company_email' => setting('company_email'),
+            'company_link' => setting('company_link'),
+            'company_color' => !empty($company_color) && $company_color != DEFAULT_COMPANY_COLOR ? $company_color : null,
+            'date_format' => setting('date_format'),
+            'time_format' => setting('time_format'),
+        ];
+
+        $this->synchronization->sync_appointment_saved($appointment, $service, $provider, $customer, $settings);
+
+        $this->notifications->notify_appointment_saved(
+            $appointment,
+            $service,
+            $provider,
+            $customer,
+            $settings,
+            $manage_mode,
+        );
+    }
+
+    /**
+     * Update an appointment.
+     *
+     * @param int $id Appointment ID.
+     */
+    public function update(int $id): void
+    {
+        try {
+            $occurrences = $this->appointments_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $original_appointment = $occurrences[0];
+
+            $appointment = request();
+
+            $this->appointments_model->api_decode($appointment, $original_appointment);
+
+            $appointment_id = $this->appointments_model->save($appointment);
+
+            $updated_appointment = $this->appointments_model->find($appointment_id);
+
+            $this->notify_and_sync_appointment($updated_appointment, 'update');
+
+            $this->appointments_model->api_encode($updated_appointment);
+
+            json_response($updated_appointment);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Delete an appointment.
+     *
+     * @param int $id Appointment ID.
+     */
+    public function destroy(int $id): void
+    {
+        try {
+            $occurrences = $this->appointments_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $deleted_appointment = $occurrences[0];
+
+            $service = $this->services_model->find($deleted_appointment['id_services']);
+
+            $provider = $this->providers_model->find($deleted_appointment['id_users_provider']);
+
+            $customer = $this->customers_model->find($deleted_appointment['id_users_customer']);
+
+            $company_color = setting('company_color');
+
+            $settings = [
+                'company_name' => setting('company_name'),
+                'company_email' => setting('company_email'),
+                'company_link' => setting('company_link'),
+                'company_color' => !empty($company_color) && $company_color != DEFAULT_COMPANY_COLOR ? $company_color : null,
+                'date_format' => setting('date_format'),
+                'time_format' => setting('time_format'),
+            ];
+
+            $this->appointments_model->delete($id);
+
+            $this->synchronization->sync_appointment_deleted($deleted_appointment, $provider);
+
+            $this->notifications->notify_appointment_deleted(
+                $deleted_appointment,
+                $service,
+                $provider,
+                $customer,
+                $settings,
+            );
+
+            response('', 204);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/api/v1/Availabilities_api_v1.php

@@ -0,0 +1,81 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Availabilities API v1 controller.
+ *
+ * @package Controllers
+ */
+class Availabilities_api_v1 extends EA_Controller
+{
+    /**
+     * Availabilities_api_v1 constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('api');
+
+        $this->api->auth();
+
+        $this->load->model('appointments_model');
+        $this->load->model('providers_model');
+        $this->load->model('services_model');
+        $this->load->model('settings_model');
+
+        $this->load->library('availability');
+    }
+
+    /**
+     * Generate the available hours based on the selected date, service and provider.
+     *
+     * This resource requires the following query parameters:
+     *
+     *   - serviceId
+     *   - providerI
+     *   - date
+     *
+     * Based on those values it will generate the available hours, just like how the booking page works.
+     *
+     * You can then safely create a new appointment starting on one of the selected hours.
+     *
+     * Notice: The returned hours are in the provider's timezone.
+     *
+     * If no date parameter is provided then the current date will be used.
+     */
+    public function get(): void
+    {
+        try {
+            $provider_id = request('providerId');
+
+            $service_id = request('serviceId');
+
+            $date = request('date');
+
+            if (!$date) {
+                $date = date('Y-m-d');
+            }
+
+            $provider = $this->providers_model->find($provider_id);
+
+            $service = $this->services_model->find($service_id);
+
+            $available_hours = $this->availability->get_available_hours($date, $service, $provider);
+
+            json_response($available_hours);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/api/v1/Customers_api_v1.php

@@ -0,0 +1,190 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Customers API v1 controller.
+ *
+ * @package Controllers
+ */
+class Customers_api_v1 extends EA_Controller
+{
+    /**
+     * Customers_api_v1 constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('api');
+
+        $this->api->auth();
+
+        $this->api->model('customers_model');
+    }
+
+    /**
+     * Get a customer collection.
+     */
+    public function index(): void
+    {
+        try {
+            $keyword = $this->api->request_keyword();
+
+            $limit = $this->api->request_limit();
+
+            $offset = $this->api->request_offset();
+
+            $order_by = $this->api->request_order_by();
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $customers = empty($keyword)
+                ? $this->customers_model->get(null, $limit, $offset, $order_by)
+                : $this->customers_model->search($keyword, $limit, $offset, $order_by);
+
+            foreach ($customers as &$customer) {
+                $this->customers_model->api_encode($customer);
+
+                if (!empty($fields)) {
+                    $this->customers_model->only($customer, $fields);
+                }
+
+                if (!empty($with)) {
+                    $this->customers_model->load($customer, $with);
+                }
+            }
+
+            json_response($customers);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Get a single customer.
+     *
+     * @param int|null $id Customer ID.
+     */
+    public function show(?int $id = null): void
+    {
+        try {
+            $occurrences = $this->customers_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $fields = $this->api->request_fields();
+
+            $customer = $this->customers_model->find($id);
+
+            $this->customers_model->api_encode($customer);
+
+            if (!empty($fields)) {
+                $this->customers_model->only($customer, $fields);
+            }
+
+            json_response($customer);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new customer.
+     */
+    public function store(): void
+    {
+        try {
+            $customer = request();
+
+            $this->customers_model->api_decode($customer);
+
+            if (array_key_exists('id', $customer)) {
+                unset($customer['id']);
+            }
+
+            $customer_id = $this->customers_model->save($customer);
+
+            $created_customer = $this->customers_model->find($customer_id);
+
+            $this->customers_model->api_encode($created_customer);
+
+            json_response($created_customer, 201);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a customer.
+     *
+     * @param int $id Customer ID.
+     */
+    public function update(int $id): void
+    {
+        try {
+            $occurrences = $this->customers_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $original_customer = $occurrences[0];
+
+            $customer = request();
+
+            $this->customers_model->api_decode($customer, $original_customer);
+
+            $customer_id = $this->customers_model->save($customer);
+
+            $updated_customer = $this->customers_model->find($customer_id);
+
+            $this->customers_model->api_encode($updated_customer);
+
+            json_response($updated_customer);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Delete a customer.
+     *
+     * @param int $id Customer ID.
+     */
+    public function destroy(int $id): void
+    {
+        try {
+            $occurrences = $this->customers_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $this->customers_model->delete($id);
+
+            response('', 204);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/api/v1/Providers_api_v1.php

@@ -0,0 +1,212 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Providers API v1 controller.
+ *
+ * @package Controllers
+ */
+class Providers_api_v1 extends EA_Controller
+{
+    /**
+     * Providers_api_v1 constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('api');
+
+        $this->api->auth();
+
+        $this->api->model('providers_model');
+    }
+
+    /**
+     * Get a provider collection.
+     */
+    public function index(): void
+    {
+        try {
+            $keyword = $this->api->request_keyword();
+
+            $limit = $this->api->request_limit();
+
+            $offset = $this->api->request_offset();
+
+            $order_by = $this->api->request_order_by();
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $providers = empty($keyword)
+                ? $this->providers_model->get(null, $limit, $offset, $order_by)
+                : $this->providers_model->search($keyword, $limit, $offset, $order_by);
+
+            foreach ($providers as &$provider) {
+                $this->providers_model->api_encode($provider);
+
+                if (!empty($fields)) {
+                    $this->providers_model->only($provider, $fields);
+                }
+
+                if (!empty($with)) {
+                    $this->providers_model->load($provider, $with);
+                }
+            }
+
+            json_response($providers);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Get a single provider.
+     *
+     * @param int|null $id Provider ID.
+     */
+    public function show(?int $id = null): void
+    {
+        try {
+            $occurrences = $this->providers_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $provider = $this->providers_model->find($id);
+
+            $this->providers_model->api_encode($provider);
+
+            if (!empty($fields)) {
+                $this->providers_model->only($provider, $fields);
+            }
+
+            if (!empty($with)) {
+                $this->providers_model->load($provider, $with);
+            }
+
+            json_response($provider);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new provider.
+     */
+    public function store(): void
+    {
+        try {
+            $provider = request();
+
+            $this->providers_model->api_decode($provider);
+
+            if (array_key_exists('id', $provider)) {
+                unset($provider['id']);
+            }
+
+            if (!array_key_exists('services', $provider)) {
+                throw new InvalidArgumentException('No services property provided.');
+            }
+
+            if (!array_key_exists('settings', $provider)) {
+                throw new InvalidArgumentException('No settings property provided.');
+            }
+
+            if (!array_key_exists('working_plan', $provider['settings'])) {
+                $provider['settings']['working_plan'] = setting('company_working_plan');
+            }
+
+            if (!array_key_exists('working_plan_exceptions', $provider['settings'])) {
+                $provider['settings']['working_plan_exceptions'] = '{}';
+            }
+
+            $provider_id = $this->providers_model->save($provider);
+
+            $created_provider = $this->providers_model->find($provider_id);
+
+            $this->providers_model->api_encode($created_provider);
+
+            json_response($created_provider, 201);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a provider.
+     *
+     * @param int $id Provider ID.
+     */
+    public function update(int $id): void
+    {
+        try {
+            $occurrences = $this->providers_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $original_provider = $occurrences[0];
+
+            $provider = request();
+
+            $this->providers_model->api_decode($provider, $original_provider);
+
+            $provider_id = $this->providers_model->save($provider);
+
+            $updated_provider = $this->providers_model->find($provider_id);
+
+            $this->providers_model->api_encode($updated_provider);
+
+            json_response($updated_provider);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Delete a provider.
+     *
+     * @param int $id Provider ID.
+     */
+    public function destroy(int $id): void
+    {
+        try {
+            $occurrences = $this->providers_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $this->providers_model->delete($id);
+
+            response('', 204);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/api/v1/Secretaries_api_v1.php

@@ -0,0 +1,198 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Secretaries API v1 controller.
+ *
+ * @package Controllers
+ */
+class Secretaries_api_v1 extends EA_Controller
+{
+    /**
+     * Secretaries_api_v1 constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('api');
+
+        $this->api->auth();
+
+        $this->api->model('secretaries_model');
+    }
+
+    /**
+     * Get a secretary collection.
+     */
+    public function index(): void
+    {
+        try {
+            $keyword = $this->api->request_keyword();
+
+            $limit = $this->api->request_limit();
+
+            $offset = $this->api->request_offset();
+
+            $order_by = $this->api->request_order_by();
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $secretaries = empty($keyword)
+                ? $this->secretaries_model->get(null, $limit, $offset, $order_by)
+                : $this->secretaries_model->search($keyword, $limit, $offset, $order_by);
+
+            foreach ($secretaries as &$secretary) {
+                $this->secretaries_model->api_encode($secretary);
+
+                if (!empty($fields)) {
+                    $this->secretaries_model->only($secretary, $fields);
+                }
+
+                if (!empty($with)) {
+                    $this->secretaries_model->load($secretary, $with);
+                }
+            }
+
+            json_response($secretaries);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Get a single secretary.
+     *
+     * @param int|null $id Secretary ID.
+     */
+    public function show(?int $id = null): void
+    {
+        try {
+            $occurrences = $this->secretaries_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $fields = $this->api->request_fields();
+
+            $secretary = $this->secretaries_model->find($id);
+
+            $this->secretaries_model->api_encode($secretary);
+
+            if (!empty($fields)) {
+                $this->secretaries_model->only($secretary, $fields);
+            }
+
+            json_response($secretary);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new secretary.
+     */
+    public function store(): void
+    {
+        try {
+            $secretary = request();
+
+            $this->secretaries_model->api_decode($secretary);
+
+            if (array_key_exists('id', $secretary)) {
+                unset($secretary['id']);
+            }
+
+            if (!array_key_exists('providers', $secretary)) {
+                throw new InvalidArgumentException('No providers property provided.');
+            }
+
+            if (!array_key_exists('settings', $secretary)) {
+                throw new InvalidArgumentException('No settings property provided.');
+            }
+
+            $secretary_id = $this->secretaries_model->save($secretary);
+
+            $created_secretary = $this->secretaries_model->find($secretary_id);
+
+            $this->secretaries_model->api_encode($created_secretary);
+
+            json_response($created_secretary, 201);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a secretary.
+     *
+     * @param int $id Secretary ID.
+     */
+    public function update(int $id): void
+    {
+        try {
+            $occurrences = $this->secretaries_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $original_secretary = $occurrences[0];
+
+            $secretary = request();
+
+            $this->secretaries_model->api_decode($secretary, $original_secretary);
+
+            $secretary_id = $this->secretaries_model->save($secretary);
+
+            $updated_secretary = $this->secretaries_model->find($secretary_id);
+
+            $this->secretaries_model->api_encode($updated_secretary);
+
+            json_response($updated_secretary);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Delete a secretary.
+     *
+     * @param int $id Secretary ID.
+     */
+    public function destroy(int $id): void
+    {
+        try {
+            $occurrences = $this->secretaries_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $this->secretaries_model->delete($id);
+
+            response('', 204);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/api/v1/Service_categories_api_v1.php

@@ -0,0 +1,196 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Service-categories API v1 controller.
+ *
+ * @package Controllers
+ */
+class Service_categories_api_v1 extends EA_Controller
+{
+    /**
+     * Service_categories_api_v1 constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('api');
+
+        $this->api->auth();
+
+        $this->api->model('service_categories_model');
+    }
+
+    /**
+     * Get a service-category collection.
+     */
+    public function index(): void
+    {
+        try {
+            $keyword = $this->api->request_keyword();
+
+            $limit = $this->api->request_limit();
+
+            $offset = $this->api->request_offset();
+
+            $order_by = $this->api->request_order_by();
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $service_categories = empty($keyword)
+                ? $this->service_categories_model->get(null, $limit, $offset, $order_by)
+                : $this->service_categories_model->search($keyword, $limit, $offset, $order_by);
+
+            foreach ($service_categories as &$service_category) {
+                $this->service_categories_model->api_encode($service_category);
+
+                if (!empty($fields)) {
+                    $this->service_categories_model->only($service_category, $fields);
+                }
+
+                if (!empty($with)) {
+                    $this->service_categories_model->load($service_category, $with);
+                }
+            }
+
+            json_response($service_categories);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Get a single service-category.
+     *
+     * @param int|null $id Service-category ID.
+     */
+    public function show(?int $id = null): void
+    {
+        try {
+            $occurrences = $this->service_categories_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $service_category = $this->service_categories_model->find($id);
+
+            $this->service_categories_model->api_encode($service_category);
+
+            if (!empty($fields)) {
+                $this->service_categories_model->only($service_category, $fields);
+            }
+
+            if (!empty($with)) {
+                $this->service_categories_model->load($service_category, $with);
+            }
+
+            json_response($service_category);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new service-category.
+     */
+    public function store(): void
+    {
+        try {
+            $service_category = request();
+
+            $this->service_categories_model->api_decode($service_category);
+
+            if (array_key_exists('id', $service_category)) {
+                unset($service_category['id']);
+            }
+
+            $service_category_id = $this->service_categories_model->save($service_category);
+
+            $created_service_category = $this->service_categories_model->find($service_category_id);
+
+            $this->service_categories_model->api_encode($created_service_category);
+
+            json_response($created_service_category, 201);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a service-category.
+     *
+     * @param int $id Service-category ID.
+     */
+    public function update(int $id): void
+    {
+        try {
+            $occurrences = $this->service_categories_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $original_category = $occurrences[0];
+
+            $service_category = request();
+
+            $this->service_categories_model->api_decode($service_category, $original_category);
+
+            $service_category_id = $this->service_categories_model->save($service_category);
+
+            $updated_service_category = $this->service_categories_model->find($service_category_id);
+
+            $this->service_categories_model->api_encode($updated_service_category);
+
+            json_response($updated_service_category);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Delete a service-category.
+     *
+     * @param int $id Service-category ID.
+     */
+    public function destroy(int $id): void
+    {
+        try {
+            $occurrences = $this->service_categories_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $this->service_categories_model->delete($id);
+
+            response('', 204);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/api/v1/Services_api_v1.php

@@ -0,0 +1,196 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Services API v1 controller.
+ *
+ * @package Controllers
+ */
+class Services_api_v1 extends EA_Controller
+{
+    /**
+     * Services_api_v1 constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('api');
+
+        $this->api->auth();
+
+        $this->api->model('services_model');
+    }
+
+    /**
+     * Get a service collection.
+     */
+    public function index(): void
+    {
+        try {
+            $keyword = $this->api->request_keyword();
+
+            $limit = $this->api->request_limit();
+
+            $offset = $this->api->request_offset();
+
+            $order_by = $this->api->request_order_by();
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $services = empty($keyword)
+                ? $this->services_model->get(null, $limit, $offset, $order_by)
+                : $this->services_model->search($keyword, $limit, $offset, $order_by);
+
+            foreach ($services as &$service) {
+                $this->services_model->api_encode($service);
+
+                if (!empty($fields)) {
+                    $this->services_model->only($service, $fields);
+                }
+
+                if (!empty($with)) {
+                    $this->services_model->load($service, $with);
+                }
+            }
+
+            json_response($services);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Get a single service.
+     *
+     * @param int|null $id Service ID.
+     */
+    public function show(?int $id = null): void
+    {
+        try {
+            $occurrences = $this->services_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $service = $this->services_model->find($id);
+
+            $this->services_model->api_encode($service);
+
+            if (!empty($fields)) {
+                $this->services_model->only($service, $fields);
+            }
+
+            if (!empty($with)) {
+                $this->services_model->load($service, $with);
+            }
+
+            json_response($service);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new service.
+     */
+    public function store(): void
+    {
+        try {
+            $service = request();
+
+            $this->services_model->api_decode($service);
+
+            if (array_key_exists('id', $service)) {
+                unset($service['id']);
+            }
+
+            $service_id = $this->services_model->save($service);
+
+            $created_service = $this->services_model->find($service_id);
+
+            $this->services_model->api_encode($created_service);
+
+            json_response($created_service, 201);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a service.
+     *
+     * @param int $id Service ID.
+     */
+    public function update(int $id): void
+    {
+        try {
+            $occurrences = $this->services_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $original_service = $occurrences[0];
+
+            $service = request();
+
+            $this->services_model->api_decode($service, $original_service);
+
+            $service_id = $this->services_model->save($service);
+
+            $updated_service = $this->services_model->find($service_id);
+
+            $this->services_model->api_encode($updated_service);
+
+            json_response($updated_service);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Delete a service.
+     *
+     * @param int $id Service ID.
+     */
+    public function destroy(int $id): void
+    {
+        try {
+            $occurrences = $this->services_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $this->services_model->delete($id);
+
+            response('', 204);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/api/v1/Settings_api_v1.php

@@ -0,0 +1,108 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Settings API v1 controller.
+ *
+ * @package Controllers
+ */
+class Settings_api_v1 extends EA_Controller
+{
+    /**
+     * Settings_api_v1 constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('api');
+
+        $this->api->auth();
+
+        $this->api->model('settings_model');
+    }
+
+    /**
+     * Get a setting collection.
+     */
+    public function index(): void
+    {
+        try {
+            $keyword = $this->api->request_keyword();
+
+            $limit = $this->api->request_limit();
+
+            $offset = $this->api->request_offset();
+
+            $order_by = $this->api->request_order_by();
+
+            $fields = $this->api->request_fields();
+
+            $settings = empty($keyword)
+                ? $this->settings_model->get(null, $limit, $offset, $order_by)
+                : $this->settings_model->search($keyword, $limit, $offset, $order_by);
+
+            foreach ($settings as &$setting) {
+                $this->settings_model->api_encode($setting);
+
+                if (!empty($fields)) {
+                    $this->settings_model->only($setting, $fields);
+                }
+            }
+
+            json_response($settings);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Get a setting value by name.
+     *
+     * @param string $name Setting name.
+     */
+    public function show(string $name): void
+    {
+        try {
+            $value = setting($name);
+
+            json_response([
+                'name' => $name,
+                'value' => $value,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Set a setting value by name.
+     *
+     * @param string $name Setting name.
+     */
+    public function update(string $name): void
+    {
+        try {
+            $value = request('value');
+
+            setting([$name => $value]);
+
+            json_response([
+                'name' => $name,
+                'value' => $value,
+            ]);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/api/v1/Unavailabilities_api_v1.php

@@ -0,0 +1,196 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Unavailabilities API v1 controller.
+ *
+ * @package Controllers
+ */
+class Unavailabilities_api_v1 extends EA_Controller
+{
+    /**
+     * Unavailabilities_api_v1 constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('api');
+
+        $this->api->auth();
+
+        $this->api->model('unavailabilities_model');
+    }
+
+    /**
+     * Get an unavailability collection.
+     */
+    public function index(): void
+    {
+        try {
+            $keyword = $this->api->request_keyword();
+
+            $limit = $this->api->request_limit();
+
+            $offset = $this->api->request_offset();
+
+            $order_by = $this->api->request_order_by();
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $unavailabilities = empty($keyword)
+                ? $this->unavailabilities_model->get(null, $limit, $offset, $order_by)
+                : $this->unavailabilities_model->search($keyword, $limit, $offset, $order_by);
+
+            foreach ($unavailabilities as &$unavailability) {
+                $this->unavailabilities_model->api_encode($unavailability);
+
+                if (!empty($fields)) {
+                    $this->unavailabilities_model->only($unavailability, $fields);
+                }
+
+                if (!empty($with)) {
+                    $this->unavailabilities_model->load($unavailability, $with);
+                }
+            }
+
+            json_response($unavailabilities);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Get a single unavailability.
+     *
+     * @param int|null $id Unavailability ID.
+     */
+    public function show(?int $id = null): void
+    {
+        try {
+            $occurrences = $this->unavailabilities_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $unavailability = $this->unavailabilities_model->find($id);
+
+            $this->unavailabilities_model->api_encode($unavailability);
+
+            if (!empty($fields)) {
+                $this->unavailabilities_model->only($unavailability, $fields);
+            }
+
+            if (!empty($with)) {
+                $this->unavailabilities_model->load($unavailability, $with);
+            }
+
+            json_response($unavailability);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new unavailability.
+     */
+    public function store(): void
+    {
+        try {
+            $unavailability = request();
+
+            $this->unavailabilities_model->api_decode($unavailability);
+
+            if (array_key_exists('id', $unavailability)) {
+                unset($unavailability['id']);
+            }
+
+            $unavailability_id = $this->unavailabilities_model->save($unavailability);
+
+            $created_unavailability = $this->unavailabilities_model->find($unavailability_id);
+
+            $this->unavailabilities_model->api_encode($created_unavailability);
+
+            json_response($created_unavailability, 201);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update an unavailability.
+     *
+     * @param int $id Unavailability ID.
+     */
+    public function update(int $id): void
+    {
+        try {
+            $occurrences = $this->unavailabilities_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $original_unavailability = $occurrences[0];
+
+            $unavailability = request();
+
+            $this->unavailabilities_model->api_decode($unavailability, $original_unavailability);
+
+            $unavailability_id = $this->unavailabilities_model->save($unavailability);
+
+            $updated_unavailability = $this->unavailabilities_model->find($unavailability_id);
+
+            $this->unavailabilities_model->api_encode($updated_unavailability);
+
+            json_response($updated_unavailability);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Delete an unavailability.
+     *
+     * @param int $id Unavailability ID.
+     */
+    public function destroy(int $id): void
+    {
+        try {
+            $occurrences = $this->unavailabilities_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $this->unavailabilities_model->delete($id);
+
+            response('', 204);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/api/v1/Webhooks_api_v1.php

@@ -0,0 +1,196 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Online Appointment Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.5.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Webhooks API v1 controller.
+ *
+ * @package Controllers
+ */
+class Webhooks_api_v1 extends EA_Controller
+{
+    /**
+     * Webhooks_api_v1 constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+
+        $this->load->library('api');
+
+        $this->api->auth();
+
+        $this->api->model('webhooks_model');
+    }
+
+    /**
+     * Get a webhook collection.
+     */
+    public function index(): void
+    {
+        try {
+            $keyword = $this->api->request_keyword();
+
+            $limit = $this->api->request_limit();
+
+            $offset = $this->api->request_offset();
+
+            $order_by = $this->api->request_order_by();
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $webhooks = empty($keyword)
+                ? $this->webhooks_model->get(null, $limit, $offset, $order_by)
+                : $this->webhooks_model->search($keyword, $limit, $offset, $order_by);
+
+            foreach ($webhooks as &$webhook) {
+                $this->webhooks_model->api_encode($webhook);
+
+                if (!empty($fields)) {
+                    $this->webhooks_model->only($webhook, $fields);
+                }
+
+                if (!empty($with)) {
+                    $this->webhooks_model->load($webhook, $with);
+                }
+            }
+
+            json_response($webhooks);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Get a single webhook.
+     *
+     * @param int|null $id Webhook ID.
+     */
+    public function show(?int $id = null): void
+    {
+        try {
+            $occurrences = $this->webhooks_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $fields = $this->api->request_fields();
+
+            $with = $this->api->request_with();
+
+            $webhook = $this->webhooks_model->find($id);
+
+            $this->webhooks_model->api_encode($webhook);
+
+            if (!empty($fields)) {
+                $this->webhooks_model->only($webhook, $fields);
+            }
+
+            if (!empty($with)) {
+                $this->webhooks_model->load($webhook, $with);
+            }
+
+            json_response($webhook);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Store a new webhook.
+     */
+    public function store(): void
+    {
+        try {
+            $webhook = request();
+
+            $this->webhooks_model->api_decode($webhook);
+
+            if (array_key_exists('id', $webhook)) {
+                unset($webhook['id']);
+            }
+
+            $webhook_id = $this->webhooks_model->save($webhook);
+
+            $created_webhook = $this->webhooks_model->find($webhook_id);
+
+            $this->webhooks_model->api_encode($created_webhook);
+
+            json_response($created_webhook, 201);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Update a webhook.
+     *
+     * @param int $id Webhook ID.
+     */
+    public function update(int $id): void
+    {
+        try {
+            $occurrences = $this->webhooks_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $original_webhook = $occurrences[0];
+
+            $webhook = request();
+
+            $this->webhooks_model->api_decode($webhook, $original_webhook);
+
+            $webhook_id = $this->webhooks_model->save($webhook);
+
+            $updated_webhook = $this->webhooks_model->find($webhook_id);
+
+            $this->webhooks_model->api_encode($updated_webhook);
+
+            json_response($updated_webhook);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+
+    /**
+     * Delete a webhook.
+     *
+     * @param int $id Webhook ID.
+     */
+    public function destroy(int $id): void
+    {
+        try {
+            $occurrences = $this->webhooks_model->get(['id' => $id]);
+
+            if (empty($occurrences)) {
+                response('', 404);
+
+                return;
+            }
+
+            $this->webhooks_model->delete($id);
+
+            response('', 204);
+        } catch (Throwable $e) {
+            json_exception($e);
+        }
+    }
+}

application/controllers/api/v1/index.html

@@ -0,0 +1,10 @@
+<html lang="en">
+<head>
+    <title>403 Forbidden</title>
+</head>
+<body>
+
+<p>Directory access is forbidden.</p>
+
+</body>
+</html>

application/controllers/index.html

@@ -0,0 +1,10 @@
+<html lang="en">
+<head>
+    <title>403 Forbidden</title>
+</head>
+<body>
+
+<p>Directory access is forbidden.</p>
+
+</body>
+</html>