<?php
if ( ! defined( 'ABSPATH' ) ) { exit; }

/**
 * ERDO_Queue — Arka Plan İşleme Kuyruğu
 *
 * Toplu dönüşüm ve silme işlemlerini WP-Cron üzerinden yürütür.
 * Tarayıcı sekmesi kapatılsa dahi işlem devam eder.
 *
 * Kuyruk anatomisi (wp_options):
 *   erdo_queue_ids      — bekleyen ID dizisi
 *   erdo_queue_action   — 'convert' | 'delete'
 *   erdo_queue_total    — toplam ID sayısı (başlangıçta)
 *   erdo_queue_done     — işlenen ID sayısı
 *   erdo_queue_errors   — hatalı ID'ler dizisi
 *   erdo_queue_status   — 'idle' | 'running' | 'done' | 'cancelled'
 *   erdo_queue_started  — Unix timestamp
 */
class ERDO_Queue {

    const HOOK         = 'erdo_bg_process';
    const INTERVAL     = 'erdo_two_min';
    const BATCH_SIZE   = 25;

    /* ------------------------------------------------------------------
       CRON INTERVAL KAYDI
    ------------------------------------------------------------------ */

    public static function register_interval() {
        add_filter( 'cron_schedules', function ( $schedules ) {
            $schedules[ self::INTERVAL ] = array(
                'interval' => 120,
                'display'  => 'Every 2 minutes (Erdo)',
            );
            return $schedules;
        } );
    }

    /* ------------------------------------------------------------------
       BAŞLAT
    ------------------------------------------------------------------ */

    public static function start( array $ids, string $action = 'convert' ) {
        if ( empty( $ids ) ) {
            return false;
        }

        self::cancel(); // Önceki kuyruğu temizle

        update_option( 'erdo_queue_ids',     $ids,       false );
        update_option( 'erdo_queue_action',  $action,    false );
        update_option( 'erdo_queue_total',   count( $ids ), false );
        update_option( 'erdo_queue_done',    0,          false );
        update_option( 'erdo_queue_errors',  array(),    false );
        update_option( 'erdo_queue_status',  'running',  false );
        update_option( 'erdo_queue_started', time(),     false );

        if ( ! wp_next_scheduled( self::HOOK ) ) {
            wp_schedule_event( time(), self::INTERVAL, self::HOOK );
        }

        // İlk batch'i hemen işle
        self::process_batch();

        return true;
    }

    /* ------------------------------------------------------------------
       İPTAL
    ------------------------------------------------------------------ */

    public static function cancel() {
        wp_clear_scheduled_hook( self::HOOK );
        update_option( 'erdo_queue_status', 'cancelled' );
        delete_option( 'erdo_queue_ids' );
    }

    /* ------------------------------------------------------------------
       BATCH İŞLE (Cron hook'u tarafından tetiklenir)
    ------------------------------------------------------------------ */

    public static function process_batch() {
        if ( get_option( 'erdo_queue_status' ) !== 'running' ) {
            wp_clear_scheduled_hook( self::HOOK );
            return;
        }

        $ids    = get_option( 'erdo_queue_ids', array() );
        $action = get_option( 'erdo_queue_action', 'convert' );
        $errors = get_option( 'erdo_queue_errors', array() );
        $done   = (int) get_option( 'erdo_queue_done', 0 );

        if ( empty( $ids ) ) {
            self::finish();
            return;
        }

        $batch = array_splice( $ids, 0, self::BATCH_SIZE );

        foreach ( $batch as $id ) {
            $id     = (int) $id;
            $result = false;

            if ( 'convert' === $action ) {
                $result = ERDO_Auditor::convert_to_webp( $id, true );
            } elseif ( 'delete' === $action ) {
                $result = ERDO_Auditor::delete_image( $id );
            }

            if ( ! $result ) {
                $errors[] = $id;
            }

            $done++;
        }

        update_option( 'erdo_queue_ids',    $ids,   false );
        update_option( 'erdo_queue_done',   $done,  false );
        update_option( 'erdo_queue_errors', $errors, false );

        if ( empty( $ids ) ) {
            self::finish();
        }
    }

    /* ------------------------------------------------------------------
       BİTİŞ
    ------------------------------------------------------------------ */

    private static function finish() {
        wp_clear_scheduled_hook( self::HOOK );
        update_option( 'erdo_queue_status', 'done' );
        delete_option( 'erdo_queue_ids' );

        // İstatistikleri güncelle
        ERDO_Auditor::clear_all_cache();
    }

    /* ------------------------------------------------------------------
       DURUM
    ------------------------------------------------------------------ */

    public static function get_status() {
        $status = get_option( 'erdo_queue_status', 'idle' );
        $total  = (int) get_option( 'erdo_queue_total', 0 );
        $done   = (int) get_option( 'erdo_queue_done', 0 );
        $errors = (array) get_option( 'erdo_queue_errors', array() );

        $pct = ( $total > 0 ) ? round( ( $done / $total ) * 100 ) : 0;

        return array(
            'status'   => $status,
            'total'    => $total,
            'done'     => $done,
            'errors'   => count( $errors ),
            'percent'  => $pct,
            'running'  => ( 'running' === $status ),
            'action'   => get_option( 'erdo_queue_action', 'convert' ),
            'started'  => (int) get_option( 'erdo_queue_started', 0 ),
        );
    }

    public static function is_running() {
        return get_option( 'erdo_queue_status' ) === 'running';
    }
}