<?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_cleanup_old_data',  [ $this, 'cleanup_old_data' ] );
        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() {
        // Cleanup must always stay scheduled (independent of scan schedule).
        if ( ! wp_next_scheduled( 'accessiq_cleanup_old_data' ) ) {
            wp_schedule_event( time(), 'daily', 'accessiq_cleanup_old_data' );
        }

        if ( ! $this->s->get( 'schedule_enabled' ) ) {
            return;
        }
        if ( ! wp_next_scheduled( 'accessiq_scheduled_scan' ) ) {
            $choice = $this->s->get( 'schedule_freq', 'weekly' );
            // 'daily' is a core recurrence; weekly/monthly are registered in add_schedules().
            $freq = ( 'daily' === $choice ) ? 'daily' : ( 'monthly' === $choice ? 'accessiq_monthly' : 'accessiq_weekly' );
            wp_schedule_event( time() + HOUR_IN_SECONDS, $freq, 'accessiq_scheduled_scan' );
        }
    }

    public function reschedule() {
        wp_clear_scheduled_hook( 'accessiq_scheduled_scan' );
        // Keep cleanup cron; only rebuild scan schedule from settings.
        $this->maybe_schedule();
    }

    /**
     * Run scheduled scan: trigger server-side scans for up to 10 published pages.
     */
    public function run_scheduled_scan() {
        $pages = get_posts( array(
            'post_type'      => array( 'page', 'post' ),
            'posts_per_page' => 10,
            'post_status'    => 'publish',
        ) );

        $count = 0;

        foreach ( $pages as $page ) {
            $url = get_permalink( $page->ID );
            if ( ! $url ) {
                continue;
            }
            // Direct in-process scan (no public AJAX endpoint).
            $result = AccessIQ_Scanner::run_scan_for_schedule( $url );
            if ( ! is_wp_error( $result ) ) {
                ++$count;
            }
        }

        // Send notification email.
        $email = $this->s->get( 'notify_email', get_option( 'admin_email' ) );
        if ( $email ) {
            wp_mail(
                $email,
                __( 'AccessIQ — Scheduled Scan Triggered', 'accessiq' ),
                /* translators: 1: number of pages, 2: site URL */
                sprintf( __( 'A scheduled accessibility scan completed for %1$d pages on %2$s.', 'accessiq' ), $count, home_url() )
            );
        }
    }

    /**
     * Delete analytics rows older than the configured retention period.
     * Runs daily via cron.
     */
    public function cleanup_old_data() {
        global $wpdb;

        $days = absint( get_option( 'accessiq_analytics_data_retention', 90 ) );
        if ( $days < 7 ) {
            $days = 7; // safety minimum
        }

        $cutoff = gmdate( 'Y-m-d H:i:s', strtotime( '-' . $days . ' days', current_time( 'timestamp' ) ) );

        // phpcs:disable WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
        $wpdb->query( $wpdb->prepare(
            'DELETE FROM `' . esc_sql( $wpdb->prefix . 'accessiq_clicks' ) . '` WHERE created_at < %s',
            $cutoff
        ) );
        $wpdb->query( $wpdb->prepare(
            'DELETE FROM `' . esc_sql( $wpdb->prefix . 'accessiq_sessions' ) . '` WHERE created_at < %s',
            $cutoff
        ) );
        $wpdb->query( $wpdb->prepare(
            'DELETE FROM `' . esc_sql( $wpdb->prefix . 'accessiq_page_views' ) . '` WHERE created_at < %s',
            $cutoff
        ) );
        // phpcs:enable

        $this->cleanup_old_scans();

        /**
         * Fires after analytics + scan retention cleanup (Pro prunes its own tables here).
         *
         * @param string $cutoff Analytics cutoff (site-local datetime).
         */
        do_action( 'accessiq_after_cleanup', $cutoff );
    }

    /**
     * Delete scan history (CPT + issues) older than the scan retention window.
     * Default 365 days; return 0 from the filter to keep scans forever.
     */
    public function cleanup_old_scans() {
        global $wpdb;

        $days = (int) apply_filters( 'accessiq_scan_retention_days', 365 );
        if ( $days > 0 ) {
            $cutoff = gmdate( 'Y-m-d H:i:s', strtotime( '-' . $days . ' days', current_time( 'timestamp' ) ) );
            do {
                $ids = get_posts( array(
                    'post_type'      => ACCESSIQ_SCAN_CPT,
                    'post_status'    => 'any',
                    'posts_per_page' => 100,
                    'fields'         => 'ids',
                    'no_found_rows'  => true,
                    'date_query'     => array( array( 'column' => 'post_date', 'before' => $cutoff ) ),
                ) );
                foreach ( $ids as $id ) {
                    wp_delete_post( $id, true );
                }
            } while ( ! empty( $ids ) );
        }

        // Orphaned issue rows (scan deleted manually or by retention).
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching,WordPress.DB.PreparedSQL.InterpolatedNotPrepared
        $wpdb->query( "DELETE i FROM {$wpdb->prefix}accessiq_issues i LEFT JOIN {$wpdb->posts} p ON p.ID = i.scan_id WHERE p.ID IS NULL" );
    }
}