<?php
/**
 * Import AJAX Handler
 * 
 * @package AllDataMigration
 * @subpackage Ajax
 */

if (!defined('ABSPATH')) {
    exit;
}

// phpcs:disable WordPress.WP.AlternativeFunctions.file_system_operations_fopen -- Required for chunk merging
// phpcs:disable WordPress.WP.AlternativeFunctions.file_system_operations_fwrite -- Required for chunk merging
// phpcs:disable WordPress.WP.AlternativeFunctions.file_system_operations_fclose -- Required for chunk merging
// phpcs:disable WordPress.WP.AlternativeFunctions.unlink_unlink -- Temp file cleanup
// phpcs:disable WordPress.WP.AlternativeFunctions.file_system_operations_rmdir -- Temp directory cleanup
// phpcs:disable WordPress.Security.NonceVerification -- Nonce verified in parent handler (alldami-site-migration.php)
// phpcs:disable WordPress.Security.ValidatedSanitizedInput -- Inputs sanitized manually
// phpcs:disable Squiz.PHP.DiscouragedFunctions.Discouraged -- Runtime config required
// phpcs:disable WordPress.PHP.DevelopmentFunctions.error_log_error_log -- Debugging (removed mostly)
// phpcs:disable WordPress.PHP.DevelopmentFunctions.error_log_print_r -- Debugging (removed mostly)
// phpcs:disable WordPress.NamingConventions.PrefixAllGlobals -- Standalone script variables


use AllDataMigration\Engine\ImportManager;
use AllDataMigration\Engine\Settings;
use AllDataMigration\Engine\ProgressState;
use AllDataMigration\Engine\ChunkConfig;

// Bu dosya AllDataMigration::handleImportAjax() tarafından include edilir

// Nonce verified in parent handler AllDataMigration::handleImportAjax() via check_ajax_referer()
// PHP limits - scoped to this import operation only
if (function_exists('set_time_limit')) {
    set_time_limit(300);
}
if (function_exists('ini_set')) {
    ini_set('memory_limit', '512M'); // phpcs:ignore WordPress.PHP.IniSet.memory_limit_Blacklisted
}

// DB Import sırasında WordPress'in tablo kontrol mekanizmasını devre dışı bırak
// Bu, DROP TABLE işlemleri sırasında "tables unavailable" hatasını önler
if (!defined('WP_INSTALLING')) {
    define('WP_INSTALLING', true);
}

// wpdb hatalarını sustur - import sırasında tablo eksikliği normal
global $wpdb;
if (isset($wpdb)) {
    $wpdb->suppress_errors(true);
    $wpdb->hide_errors();
}

$step = sanitize_text_field($_POST['step'] ?? '');
$jobId = sanitize_text_field($_POST['job_id'] ?? '');

// Path sanitization: sanitize_text_field first, then normalize
$zipPath = isset($_POST['zip_path']) ? wp_normalize_path(sanitize_text_field(wp_unslash($_POST['zip_path']))) : '';

// Path traversal koruması
if (!empty($zipPath) && defined('ALLDAMI_TEMP_DIR')) {
    $allowedDir = wp_normalize_path(ALLDAMI_TEMP_DIR);
    if (strpos($zipPath, $allowedDir) !== 0) {
        wp_send_json_error(['message' => 'Geçersiz dosya yolu: Güvenlik ihlali']);
    }
}

try {

    // Chunk upload işlemi
    if ($step === 'upload') {
        handleChunkUpload();
        exit;
    }

    $progress = new ProgressState();

    // Init adımı
    if ($step === 'init') {

        if (empty($zipPath)) {
            wp_send_json_error(['message' => 'DEBUG: Zip Path boş geldi! Lütfen sayfayı yenilemeden tekrar yükleme yapın.']);
        }

        if (!file_exists($zipPath)) {
            wp_send_json_error(['message' => 'DEBUG: Dosya bulunamadı: ' . $zipPath]);
        }

        $config = new ChunkConfig(true);
        $jobId = $progress->init('import', $config);

        // Security Token Oluştur
        $importToken = bin2hex(random_bytes(32));
        $tokenCreatedAt = time(); // Token expiry için

        // Settings'i ve token'ı state'e kaydet
        $settings = Settings::getInstance();
        $progress->setResumePointer([
            'zip_path' => $zipPath,
            'import_token' => $importToken,
            'import_token_created_at' => $tokenCreatedAt,
            'settings' => [
                'security_import_token_enabled' => $settings->get('security_import_token_enabled', true)
            ]
        ]);

        $importManager = new ImportManager($progress, $zipPath);
        $result = $importManager->initialize();

        wp_send_json_success([
            'job_id' => $jobId,
            'import_token' => $importToken, // Frontend'e döndür
            'next_step' => $result['next_step'],
            'progress' => $progress->getProgress()
        ]);
    }

    // Devam eden job
    if (!$progress->load($jobId)) {
        wp_send_json_error(['message' => 'Geçersiz job ID.']);
    }

    $pointer = $progress->getResumePointer();
    $zipPath = $pointer['zip_path'] ?? $zipPath;

    $importManager = new ImportManager($progress, $zipPath);

    // Debug: Log which step is about to be processed
    error_log('WP Cloner: Processing step = ' . $step . ' for job = ' . $jobId);

    switch ($step) {
        case 'extract':
            $result = $importManager->extract();
            break;

        case 'preflight':
            $result = $importManager->preflight();
            break;

        case 'db_import':
            error_log('AJAX: Case db_import triggered');
            $result = $importManager->importDbChunk();
            break;

        case 'file_restore':
            $result = $importManager->restoreFilesChunk();
            break;

        case 'replace':
            $result = $importManager->processReplacements();
            break;

        case 'finalize':
            $result = $importManager->finalize();
            break;

        default:
            wp_send_json_error(['message' => 'Geçersiz adım: ' . $step]);
    }

    if (isset($result['status']) && $result['status'] === 'completed') {
        wp_send_json_success([
            'status' => 'completed',
            'progress' => $progress->getProgress()
        ]);
    } else {
        wp_send_json_success([
            'job_id' => $jobId,
            'next_step' => $result['next_step'] ?? null,
            'progress' => $progress->getProgress()
        ]);
    }

} catch (\Throwable $e) {
    $msg = 'FATAL ERROR: ' . $e->getMessage() . ' in ' . $e->getFile() . ':' . $e->getLine();
    error_log($msg);

    if (isset($progress) && $progress instanceof ProgressState) {
        $progress->setError($msg);
    }

    wp_send_json_error([
        'message' => $msg,
        'progress' => isset($progress) ? $progress->getProgress() : null
    ]);
} catch (\Exception $e) {
    $msg = 'EXCEPTION: ' . $e->getMessage();
    error_log($msg);

    if (isset($progress) && $progress instanceof ProgressState) {
        $progress->setError($msg);
    }

    wp_send_json_error([
        'message' => $msg,
        'progress' => isset($progress) ? $progress->getProgress() : null
    ]);
}

/**
 * Chunk upload işleyici
 */
function handleChunkUpload(): void
{
    if (!isset($_FILES['chunk'])) {
        wp_send_json_error(['message' => 'Dosya chunk bulunamadı.']);
    }

    $uploadId = sanitize_text_field($_POST['upload_id'] ?? '');
    $chunkIndex = (int) ($_POST['chunk_index'] ?? 0);
    $totalChunks = (int) ($_POST['total_chunks'] ?? 0);
    $filename = sanitize_file_name($_POST['filename'] ?? 'backup.zip');

    if (empty($uploadId)) {
        wp_send_json_error(['message' => 'Upload ID gerekli.']);
    }

    // Geçici dizin
    $tempDir = ALLDAMI_TEMP_DIR . 'uploads/' . $uploadId . '/';
    if (!is_dir($tempDir)) {
        wp_mkdir_p($tempDir);
    }

    // Chunk'ı kaydet - WordPress uyumlu yöntem
    $chunkPath = $tempDir . 'chunk_' . str_pad($chunkIndex, 5, '0', STR_PAD_LEFT);
    // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_read_file_put_contents
    file_put_contents($chunkPath, file_get_contents($_FILES['chunk']['tmp_name']));

    // Tüm chunk'lar yüklendi mi?
    if ($chunkIndex + 1 >= $totalChunks) {
        // Chunk'ları birleştir
        $finalPath = ALLDAMI_TEMP_DIR . $uploadId . '_' . $filename;
        $finalFile = fopen($finalPath, 'wb');

        for ($i = 0; $i < $totalChunks; $i++) {
            $chunkFile = $tempDir . 'chunk_' . str_pad($i, 5, '0', STR_PAD_LEFT);
            if (file_exists($chunkFile)) {
                fwrite($finalFile, file_get_contents($chunkFile));
                @unlink($chunkFile);
            }
        }

        fclose($finalFile);

        // Temp dizini temizle
        @rmdir($tempDir);

        wp_send_json_success([
            'completed' => true,
            'file_path' => $finalPath,
            'filename' => $filename
        ]);
    } else {
        wp_send_json_success([
            'completed' => false,
            'chunk_index' => $chunkIndex
        ]);
    }
}