<?php
if ( ! defined( 'ABSPATH' ) ) exit;

class AccessIQ_Scheduler {

    private static $instance = null;
    private $s;

    public static function instance() {
        if ( null === self::$instance ) self::$instance = new self();
        return self::$instance;
    }

    private function __construct() {
        $this->s = AccessIQ_Settings::instance();
        add_action( 'accessiq_scheduled_scan', [ $this, 'run_scheduled_scan' ] );
        add_action( 'accessiq_settings_saved', [ $this, 'reschedule' ] );
        add_filter( 'cron_schedules',           [ $this, 'add_schedules' ] );
        $this->maybe_schedule();
    }

    public function add_schedules( $schedules ) {
        $schedules['accessiq_weekly']  = [ 'interval' => WEEK_IN_SECONDS,      'display' => 'Weekly' ];
        $schedules['accessiq_monthly'] = [ 'interval' => MONTH_IN_SECONDS,     'display' => 'Monthly' ];
        return $schedules;
    }

    public function maybe_schedule() {
        if ( ! $this->s->get( 'schedule_enabled' ) ) return;
        if ( ! wp_next_scheduled( 'accessiq_scheduled_scan' ) ) {
            $freq = 'accessiq_' . $this->s->get( 'schedule_freq', 'weekly' );
            wp_schedule_event( time(), $freq, 'accessiq_scheduled_scan' );
        }
    }

    public function reschedule() {
        wp_clear_scheduled_hook( 'accessiq_scheduled_scan' );
        $this->maybe_schedule();
    }

    /**
     * Run scheduled scan on all published pages.
     */
    public function run_scheduled_scan() {
        $pages = get_posts( [ 'post_type' => [ 'page', 'post' ], 'posts_per_page' => 20, 'post_status' => 'publish' ] );

        foreach ( $pages as $page ) {
            // Queue scan — actual DOM scan will fire on next admin visit
            // (server-side full DOM scan requires headless browser; mark pages as pending)
            update_post_meta( $page->ID, '_accessiq_scan_pending', true );
        }

        // Send notification email
        $email = $this->s->get( 'notify_email', get_option( 'admin_email' ) );
        if ( $email ) {
            wp_mail(
                $email,
                __( 'AccessIQ — Scheduled Scan Queued', 'accessiq' ),
                /* translators: 1: number of pages, 2: site URL */
                sprintf( __( 'A scheduled accessibility scan has been queued for %1$d pages on %2$s.', 'accessiq' ), count( $pages ), home_url() )
            );
        }
    }
}