<?php
require_once __DIR__ . '/../includes/config.php';

class Backup {
    private $backup_path;
    private $db_config;
    
    public function __construct() {
        $this->backup_path = __DIR__ . '/../backups';
        if (!file_exists($this->backup_path)) {
            mkdir($this->backup_path, 0755, true);
        }
        
        $this->db_config = [
            'host' => DB_SERVER,
            'user' => DB_USERNAME,
            'pass' => DB_PASSWORD,
            'name' => DB_NAME
        ];
    }
    
    public function createBackup() {
        $timestamp = date('Y-m-d_H-i-s');
        $backup_file = $this->backup_path . '/backup_' . $timestamp;
        
        // Backup database
        $this->backupDatabase($backup_file . '.sql');
        
        // Backup files
        $this->backupFiles($backup_file . '.zip');
        
        // Clean old backups (keep last 5)
        $this->cleanOldBackups();
        
        return true;
    }
    
    private function backupDatabase($file) {
        $command = sprintf(
            'mysqldump --host=%s --user=%s --password=%s %s > %s',
            escapeshellarg($this->db_config['host']),
            escapeshellarg($this->db_config['user']),
            escapeshellarg($this->db_config['pass']),
            escapeshellarg($this->db_config['name']),
            escapeshellarg($file)
        );
        
        exec($command, $output, $return_var);
        if ($return_var !== 0) {
            throw new Exception('Database backup failed');
        }
    }
    
    private function backupFiles($file) {
        $root_path = __DIR__ . '/..';
        $exclude_dirs = ['backups', 'cache', 'logs', 'vendor'];
        
        $zip = new ZipArchive();
        if ($zip->open($file, ZipArchive::CREATE | ZipArchive::OVERWRITE) !== true) {
            throw new Exception('Cannot create zip file');
        }
        
        $files = new RecursiveIteratorIterator(
            new RecursiveDirectoryIterator($root_path),
            RecursiveIteratorIterator::LEAVES_ONLY
        );
        
        foreach ($files as $name => $file) {
            if ($file->isDir()) {
                continue;
            }
            
            $filePath = $file->getRealPath();
            $relativePath = substr($filePath, strlen($root_path) + 1);
            
            // Skip excluded directories
            $skip = false;
            foreach ($exclude_dirs as $exclude) {
                if (strpos($relativePath, $exclude . '/') === 0) {
                    $skip = true;
                    break;
                }
            }
            
            if (!$skip) {
                $zip->addFile($filePath, $relativePath);
            }
        }
        
        $zip->close();
    }
    
    private function cleanOldBackups($keep = 5) {
        $files = glob($this->backup_path . '/*');
        usort($files, function($a, $b) {
            return filemtime($b) - filemtime($a);
        });
        
        if (count($files) > $keep) {
            for ($i = $keep; $i < count($files); $i++) {
                unlink($files[$i]);
            }
        }
    }
    
    public function restore($backup_date) {
        $sql_file = $this->backup_path . '/backup_' . $backup_date . '.sql';
        $zip_file = $this->backup_path . '/backup_' . $backup_date . '.zip';
        
        if (!file_exists($sql_file) || !file_exists($zip_file)) {
            throw new Exception('Backup files not found');
        }
        
        // Restore database
        $command = sprintf(
            'mysql --host=%s --user=%s --password=%s %s < %s',
            escapeshellarg($this->db_config['host']),
            escapeshellarg($this->db_config['user']),
            escapeshellarg($this->db_config['pass']),
            escapeshellarg($this->db_config['name']),
            escapeshellarg($sql_file)
        );
        
        exec($command, $output, $return_var);
        if ($return_var !== 0) {
            throw new Exception('Database restore failed');
        }
        
        // Restore files
        $zip = new ZipArchive();
        if ($zip->open($zip_file) !== true) {
            throw new Exception('Cannot open backup archive');
        }
        
        $zip->extractTo(__DIR__ . '/..');
        $zip->close();
        
        return true;
    }
}