add_action('admin_post_export_trendyol_report_csv', 'export_trendyol_report_csv');

function export_trendyol_report_csv() {
    global $wpdb;

    $products_table = $wpdb->prefix . 'trendyol_products';
    $history_table  = $wpdb->prefix . 'trendyol_products_history';

    $rows = $wpdb->get_results("
        SELECT h.barcode, h.title, h.on_sale AS old_status, c.on_sale AS current_status
        FROM {$history_table} h
        JOIN {$products_table} c ON c.barcode = h.barcode
    ", ARRAY_A);

    // CSV başlıkları
    header('Content-Type: text/csv; charset=utf-8');
    header('Content-Disposition: attachment; filename=trendyol-raporu.csv');

    $output = fopen('php://output', 'w');
    fputcsv($output, ['Barkod', 'Başlık', 'Önceki Durum', 'Şimdiki Durum']);

    // Satırları yaz
    foreach ($rows as $row) {
        fputcsv($output, [
            $row['barcode'],
            $row['title'],
            $row['old_status'] ? 'Aktif' : 'Pasif',
            $row['current_status'] ? 'Aktif' : 'Pasif',
        ]);
    }

    fclose($output);
    exit;
}