<?php
defined('ABSPATH') || exit;

GFForms::include_feed_addon_framework();

class ALPHAGF_Google_Calendar extends GFFeedAddOn {
    protected $_version = ALPHAGF_VERSION;
    protected $_min_gravityforms_version = '2.5';
    protected $_slug = 'alphagf_google_calendar';
    protected $_path = 'alpha-addons-for-gravity-forms/gf-alpha-addons.php';
    protected $_full_path = __FILE__;
    protected $_title = 'Gravity Forms Google Calendar';
    protected $_short_title = 'Google Calendar';
    protected $_multiple_feeds = false;
    protected $_async_feed_processing = true;
    private static $_instance = null;

    const ALPHAGF_OAUTH2_AUTH_URL   = 'https://accounts.google.com/o/oauth2/v2/auth';
    const ALPHAGF_AUTH_CALENDAR     = 'https://www.googleapis.com/auth/calendar openid profile email';

    /**
     * Get an instance of this class.
     *
     * @return ALPHAGF_Google_Calendar
     */
    public static function get_instance() {
        if (self::$_instance == null) {
            self::$_instance = new ALPHAGF_Google_Calendar();
        }

        return self::$_instance;
    }

    public function get_menu_icon() {
        return 'gform-icon alphagf_icon icon-google-calendar';
    }

    public function pre_init() {
        parent::pre_init();

        if ($this->is_gravityforms_supported()) {
            require_once('google-calendar-api.php');
        }
    }

    /**
     * Initialize hooks required for admin.
     *
     * @since 1.0
     *
     * @return void
     */
    public function init() {
        parent::init();

        $this->add_delayed_payment_support(
            array(
                'option_label' => esc_html__('Add data to Google Calendar only when payment is received.', 'alpha-addons-for-gravity-forms'),
            )
        );

        add_action('wp_ajax_alphagf_gc_revoke_token', [$this, 'revoke_token']);
    }

    public function styles() {
        $styles = array(
            array(
                'handle'  => 'alphagf_settings_style',
                'src'     => ALPHAGF_ASSETS . '/css/alphagf_addons_admin.css',
                'version' => $this->_version,
                'enqueue' => array(
                    array(
                        'admin_page' => array('plugin_settings'),
                        'tab'        => 'alphagf_google_calendar'
                    )
                )
            )
        );

        return array_merge(parent::styles(), $styles);
    }

    public function scripts() {
        $scripts = array(
            array(
                'handle'  => 'alphagf_google_calendar_admin_script',
                'src'     => trailingslashit($this->get_base_url()) . 'js/alphagf-google-calendar.js',
                'version' => $this->_version,
                'deps'    => array('jquery'),
                'in_footer' => true,
                'callback' => array($this, 'localize_admin_scripts'),
                'enqueue' => array(
                    array(
                        'admin_page' => array('plugin_settings'),
                        'tab'        => 'alphagf_google_calendar'
                    ),
                )
            ),
        );

        return array_merge(parent::scripts(), $scripts);
    }

    public function localize_admin_scripts() {
        wp_localize_script('alphagf_google_calendar_admin_script', 'alphagf_gc_vars', array(
            'ajax_url'     => admin_url('admin-ajax.php'),
            'nonce'        => wp_create_nonce('alphagf_gc_nonce'),
            'settings_url' => admin_url('admin.php?page=gf_settings&subview=alphagf_google_calendar'),
        ));
    }

    public function feed_settings_fields() {
        return array(
            array(
                'title'  => esc_html__('Google Calendar Settings', 'alpha-addons-for-gravity-forms'),
                'fields' => array(
                    array(
                        'label'     => esc_html__('Enable', 'alpha-addons-for-gravity-forms'),
                        'name'      => 'is_enable',
                        'type'      => 'toggle',
                        'default_value' => false,
                    ),
                    array(
                        'name'       => 'calendar_list',
                        'label'      => esc_html__('Calendar List', 'alpha-addons-for-gravity-forms'),
                        'type'       => 'select',
                        'required'   => true,
                        'choices'    => $this->get_calender_lists(),
                        'dependency' => array(
                            'live'     => true,
                            'fields' => array(
                                array(
                                    'field' => 'is_enable',
                                ),
                            ),
                        )
                    ),
                    array(
                        'label'     => esc_html__('Event Type', 'alpha-addons-for-gravity-forms'),
                        'name'      => 'event_type',
                        'type'      => 'select',
                        'required'  => true,
                        'choices'   => array(
                            array(
                                'label' => esc_html__('All Day Event', 'alpha-addons-for-gravity-forms'),
                                'value' => 'event',
                            )
                        ),
                        'dependency' => array(
                            'live'     => true,
                            'fields' => array(
                                array(
                                    'field' => 'is_enable',
                                ),
                            ),
                        )
                    ),
                    array(
                        'name'      => 'event',
                        'type'      => 'field_map',
                        'field_map' => array(
                            array(
                                'name'       => 'title',
                                'label'      => esc_html__('Event Title', 'alpha-addons-for-gravity-forms'),
                                'required'   => false,
                                'tooltip'    => esc_html__('Please choose the event title field', 'alpha-addons-for-gravity-forms'),
                            ),
                            array(
                                'name'       => 'start_date',
                                'label'      => esc_html__('Start Date', 'alpha-addons-for-gravity-forms'),
                                'required'   => true,
                                'field_type' => array('date'),
                                'tooltip'    => esc_html__('Please choose the start date', 'alpha-addons-for-gravity-forms'),
                            ),
                            array(
                                'name'       => 'end_date',
                                'label'      => esc_html__('End Date', 'alpha-addons-for-gravity-forms'),
                                'required'   => true,
                                'field_type' => array('date'),
                                'tooltip'    => esc_html__('Please choose the start date', 'alpha-addons-for-gravity-forms'),
                            ),
                            array(
                                'name'       => 'location',
                                'label'      => esc_html__('Location', 'alpha-addons-for-gravity-forms'),
                                'required'   => false,
                                'tooltip'    => esc_html__('Please choose the event location', 'alpha-addons-for-gravity-forms'),
                            )
                        ),
                        'dependency' => array(
                            'live'     => true,
                            'fields' => array(
                                array(
                                    'field' => 'is_enable',
                                )
                            ),
                        )
                    ),

                )
            ),
            array(
                'title'  => esc_html__('Conditional logic', 'alpha-addons-for-gravity-forms'),
                'fields' => array(
                    array(
                        'type'           => 'feed_condition',
                        'name'           => 'feed-condition',
                        'label'          => esc_html__('Conditions', 'alpha-addons-for-gravity-forms'),
                        'checkbox_label' => esc_html__('Enable conditional processing', 'alpha-addons-for-gravity-forms')
                    ),
                ),
            )
        );
    }

    public function get_calender_lists() {
        $calender_lists = get_transient(ALPHAGF_Google_Calendar_API::ALPHAGF_GC_CALENDER_LIST);

        if (! is_array($calender_lists) || empty($calender_lists)) {
            $calender_lists = ALPHAGF_Google_Calendar_API::get_calendar_lists();
        }

        $choices = [
            [
                'label' => esc_html__('Select a calendar', 'alpha-addons-for-gravity-forms'),
                'value' => '',
            ],
        ];

        if (! empty($calender_lists)) {
            foreach ($calender_lists as $value) {
                if (empty($value['id'])) {
                    continue;
                }

                $choices[] = [
                    'label' => rgar($value, 'summary', $value['id']),
                    'value' => $value['id'],
                ];
            }
        }

        return $choices;
    }

    public function process_feed($feed, $entry, $form) {

        if (! rgars($feed, 'meta/is_enable')) {
            return $entry;
        }

        if (! $this->initialize_gc_token()) {
            $this->add_feed_error(esc_html__('Google Calendar is not connected.', 'alpha-addons-for-gravity-forms'), $feed, $entry, $form);
            return $entry;
        }

        $calendar_id = rgars($feed, 'meta/calendar_list');
        $start_date  = $this->normalize_date($this->get_field_value($form, $entry, rgars($feed, 'meta/event_start_date')));
        $end_date    = $this->normalize_date($this->get_field_value($form, $entry, rgars($feed, 'meta/event_end_date')));

        if (empty($calendar_id) || ! $start_date) {
            $this->add_feed_error(esc_html__('Unable to create the event: a calendar and a valid start date are required.', 'alpha-addons-for-gravity-forms'), $feed, $entry, $form);
            return $entry;
        }

        // All-day events use an exclusive end date, so add a day to include the chosen end date.
        // This also keeps single-day events (start == end) valid, which Google otherwise rejects.
        if (! $end_date || $end_date < $start_date) {
            $end_date = $start_date;
        }

        $end_date = gmdate('Y-m-d', strtotime($end_date . ' +1 day'));

        $data = [
            'summary'       =>  $this->get_field_value($form, $entry, rgars($feed, 'meta/event_title')),
            'location'      =>  $this->get_field_value($form, $entry, rgars($feed, 'meta/event_location')),
            'start'         =>  [
                'date' => $start_date,
            ],
            'end'           => [
                'date' => $end_date,
            ],
            'reminders' => [
                'useDefault' => false,
            ]
        ];

        $result = ALPHAGF_Google_Calendar_API::make_request($calendar_id, $data, 'POST');

        if (is_wp_error($result)) {
            $this->add_feed_error(
                sprintf(
                    /* translators: %s: Error message returned by Google. */
                    esc_html__('Unable to send into google calendar: %s', 'alpha-addons-for-gravity-forms'),
                    $result->get_error_message()
                ),
                $feed,
                $entry,
                $form
            );
        } else {
            $this->add_note($entry['id'], esc_html__('Entry sent successfully to google calendar', 'alpha-addons-for-gravity-forms'), 'success');
            $this->log_debug(__METHOD__ . '(): Event created successfully.'); // phpcs:ignore
        }

        return $entry;
    }

    /**
     * Convert a date field value to Y-m-d, which is what Google expects for all-day events.
     *
     * @return string Empty string when the value isn't a date.
     */
    private function normalize_date($value) {
        $value = trim((string) $value);

        if ('' === $value) {
            return '';
        }

        $timestamp = strtotime($value);

        return $timestamp ? gmdate('Y-m-d', $timestamp) : '';
    }

    public function plugin_settings_fields() {
        return array(
            array(
                'title'  => esc_html__('Google Calendar Settings', 'alpha-addons-for-gravity-forms'),
                // translators: %1 is an opening <a> tag, and %2 is a closing </a> tag.
                'description' => sprintf(esc_html__('Create a Google Console app to integrate your Google Calendar with Gravity Forms. %1$sClick here%2$s to create your app.', 'alpha-addons-for-gravity-forms'), '<a href="https://console.cloud.google.com/" target="_blank">', '</a>'),
                'fields' => array(
                    array(
                        'name'    => 'client_id',
                        'label'   => esc_html__('Client ID', 'alpha-addons-for-gravity-forms'),
                        'type'    => 'text',
                        'class'   => 'medium',
                        // 'feedback_callback' => [$this, 'is_key_valid'],
                    ),
                    array(
                        'name'    => 'client_secret',
                        'label'   => esc_html__('Client Secret', 'alpha-addons-for-gravity-forms'),
                        'type'    => 'text',
                        'class'   => 'medium',
                    ),
                    array(
                        'name'    => 'redirect_uri',
                        'label'   => esc_html__('Redirect URI', 'alpha-addons-for-gravity-forms'),
                        'type'    => 'text',
                        'class'   => 'medium',
                        'default_value' => admin_url('admin.php?page=gf_settings&subview=alphagf_google_calendar'),
                    ),
                    array(
                        'name'    => 'client_token',
                        'label'   => esc_html__('Client Token Code', 'alpha-addons-for-gravity-forms'),
                        'type'    => 'text',
                        'class'   => 'medium',
                        'feedback_callback' => [$this, 'token_validation_callback'],
                    ),
                    array(
                        'name'    => 'authorize_btn',
                        'type'    => 'authorize_account',
                        'class'   => 'medium',
                    ),
                ),
            ),
        );
    }

    public function token_validation_callback() {
        $code = rgpost('_gform_setting_client_token');

        if (get_option('alphagf_gc_auth_verified', 0)) {
            return true;
        }

        if (empty($code)) {
            return '';
        }

        $result = ALPHAGF_Google_Calendar_API::authenticate($code);

        if (! $result) {
            return false;
        }

        return true;
    }

    public function settings_authorize_account($field) {
        $settings       = $this->get_plugin_settings();
        $is_auth_verified = get_option('alphagf_gc_auth_verified', 0);

        if (! rgar($field, 'value')) {
            $field['value'] = esc_html__('Generate Token', 'alpha-addons-for-gravity-forms');
        }

        $client_id      = rgar($settings, 'client_id');

        $redirect_uri   = rgar($settings, 'redirect_uri');

        if (empty($redirect_uri)) {
            $redirect_uri = admin_url('admin.php?page=gf_settings&subview=alphagf_google_calendar');
        }

        $auth_url = self::ALPHAGF_OAUTH2_AUTH_URL . '?scope=' . rawurlencode(self::ALPHAGF_AUTH_CALENDAR) . '&redirect_uri=' . rawurlencode($redirect_uri) . '&response_type=code&prompt=consent&client_id=' . rawurlencode((string) $client_id) . '&access_type=offline';

        if ($is_auth_verified) {
            $html = $this->authorized_account();
            $html .= '<a href="#" id="alphagf_gc_revoke_token" class="alphagf_setting_btn">' . esc_html__('Revoke Token', 'alpha-addons-for-gravity-forms') . '</a>';
        } else {
            $html = '<a href="' . esc_url($auth_url) . '" target="_blank" class="alphagf_setting_btn">' . esc_html__('Generate Token', 'alpha-addons-for-gravity-forms') . '</a>';
        }

        return $html;
    }

    public function authorized_account() {
        $verified       = get_option('alphagf_gc_auth_verified', 0);
        $auth_account   = get_option('alphagf_gc_auth_account', []);

        if ($verified && !empty($auth_account)) {
            $html = '<div class="alert gforms_note_success">';
            $html .= '<div class="alphagf_auth_verified_wrap">';

            $html .= wp_kses_post(
                sprintf(
                    /* translators: 1: User Email Address, 2: Date of authorization */
                    __('Authorized connection to %1$s on %2$s', 'alpha-addons-for-gravity-forms'),
                    '<code>' . esc_html($auth_account['email']) . '</code>', // %1$s
                    esc_html(wp_date('F d, Y \a\t h:i:s A', (int) rgar($auth_account, 'time'))) // %2$s
                )
            );

            $html .= '</div>';
            $html .= '</div>';
            return $html;
        }

        return '';
    }

    public function revoke_token() {
        check_ajax_referer('alphagf_gc_nonce', 'nonce');

        if (! GFCommon::current_user_can_any('gravityforms_edit_settings')) {
            wp_send_json_error(array('message' => esc_html__('Sorry, you are not allowed to do that.', 'alpha-addons-for-gravity-forms')), 403);
        }

        $settings = get_option('alphagf_gc_token_data', []);
        // Revoking the refresh token also invalidates every access token issued from it.
        $token    = rgar($settings, 'refresh_token') ? $settings['refresh_token'] : rgar($settings, 'access_token');
        $result   = ALPHAGF_Google_Calendar_API::revoke_token($token);

        if (! $result) {
            wp_send_json_error();
        }

        wp_send_json_success($result);
    }

    public function can_create_feed() {
        return $this->initialize_gc_token();
    }

    public function initialize_gc_token() {
        $token = get_option('alphagf_gc_token_data', []);

        if (isset($token['access_token']) && $token['access_token'] != '') {
            return true;
        }

        return false;
    }
}