<?php
require_once '../includes/db.php';
require_once '../includes/functions.php';

ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);
ini_set('log_errors', 1);
ini_set('error_log', 'backup_debug.log');

set_time_limit(300); // 5 minutes
ini_set('memory_limit', '512M');

requireAdmin();

if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['generate_backup'])) {
    $date = date("Y-m-d_H-i");
    $backupDir = "backups/";
    if (!is_dir($backupDir)) {
        if (!mkdir($backupDir, 0755, true)) {
            die("Could not create backup directory. Check permissions.");
        }
    }
    
    if (!is_writable($backupDir)) {
        die("Backup directory is not writable. Check permissions.");
    }

    // 1. Backup Audio Files
    $audioTar = $backupDir . "backup_audio_$date.tar.gz";
    $audioPath = realpath("../assets/uploads/audio");
    shell_exec("tar -czf " . escapeshellarg($audioTar) . " -C " . escapeshellarg($audioPath) . " .");

    // 2. Backup Database (PHP-based SQL Dump)
    $dbSql = $backupDir . "backup_db_$date.sql";
    $tables = ['episodes', 'plays', 'settings', 'admins', 'subscriptions'];
    $sqlDump = "-- Database Backup\n-- Date: " . date("Y-m-d H:i:s") . "\n";
    $sqlDump .= "SET FOREIGN_KEY_CHECKS = 0;\n\n";

    foreach ($tables as $table) {
        $stmt = $pdo->query("SELECT * FROM $table");
        $rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
        
        $sqlDump .= "TRUNCATE TABLE `$table`;\n";
        foreach ($rows as $row) {
            $keys = array_keys($row);
            $values = array_map(function($v) use ($pdo) { 
                return ($v === null) ? "NULL" : $pdo->quote($v); 
            }, array_values($row));
            $sqlDump .= "INSERT INTO `$table` (`" . implode("`, `", $keys) . "`) VALUES (" . implode(", ", $values) . ");\n";
        }
        $sqlDump .= "\n";
    }
    
    file_put_contents($dbSql, $sqlDump . "\nSET FOREIGN_KEY_CHECKS = 1;");
    
    // Tar the SQL
    $dbTar = $backupDir . "backup_db_$date.tar.gz";
    shell_exec("tar -czf " . escapeshellarg($dbTar) . " -C " . escapeshellarg($backupDir) . " " . escapeshellarg(basename($dbSql)));
    unlink($dbSql);

    // 3. Backup Site Files (Excluding uploads and backups)
    $siteTar = $backupDir . "backup_site_$date.tar.gz";
    $rootPath = realpath("../");
    $exclude = " --exclude='./assets/uploads' --exclude='./admin/backups' --exclude='./.git'";
    shell_exec("tar -czf " . escapeshellarg($siteTar) . " -C " . escapeshellarg($rootPath) . $exclude . " .");

    logActivity($_SESSION['admin_id'], 'BACKUP_GENERATE', "Generated full system backup: Audio, DB, and Site files.");
    header("Location: system.php?backup=success");
    exit;
}
?>