<?php
/**
 * Advanced File Recovery Script (Batch Mode & Direct Download)
 * Fixes 502 Bad Gateway & Download Timeouts.
 */
// Configuration
$batchSize = 10; // Reduced batch size for safety
$stateFile = 'recovery_state.json';
$zipFile = 'full_backup.zip';
$scriptName = basename(__FILE__);
// Disable timeouts as much as possible
@ini_set('max_execution_time', 0);
@set_time_limit(0);
ignore_user_abort(true);
$step = isset($_GET['step']) ? $_GET['step'] : 'ui';
// --- API HANDLING ---
if ($step === 'scan') {
    // Phase 1: Scan all files and save list
    try {
        if (file_exists($zipFile))
            unlink($zipFile); // Clear old zip
        if (file_exists($stateFile))
            unlink($stateFile); // Clear old state
        $files = new RecursiveIteratorIterator(
            new RecursiveDirectoryIterator(__DIR__, RecursiveDirectoryIterator::SKIP_DOTS),
            RecursiveIteratorIterator::LEAVES_ONLY
        );
        $fileList = [];
        foreach ($files as $name => $file) {
            // Skip script files
            $fname = $file->getFilename();
            if ($fname == $scriptName || $fname == $stateFile || $fname == $zipFile) {
                continue;
            }
            if ($file->isFile()) {
                $fileList[] = $file->getRealPath();
            }
        }
        // Save state
        file_put_contents($stateFile, json_encode([
            'files' => $fileList,
            'total' => count(