import 'dart:convert';
import 'dart:io';

class FirmwareVersionInfo {
  final String version;
  final String fileName;
  final String downloadUrl;

  FirmwareVersionInfo({
    required this.version,
    required this.fileName,
    required this.downloadUrl,
  });

  @override
  String toString() {
    return 'FirmwareVersionInfo{version: $version, fileName: $fileName, downloadUrl: $downloadUrl}';
  }
}

class FirmwareVersionService {
  /// 从远程URL获取最新的固件版本信息
  /// [baseUrl] 基础URL，如 "https://share.file.he-info.cn"
  /// [firmwarePath] 固件路径，如 "/ota/aithv2/"
  static Future<FirmwareVersionInfo?> getLatestFirmwareVersion({
    required String baseUrl,
    required String firmwarePath,
  }) async {
    try {
      // 构建完整的API URL
      final apiUrl = '$baseUrl/~/api/get_file_list?uri=$firmwarePath';
      
      // 发送HTTP请求 - 使用基础的http客户端，不依赖项目特定实现
      final response = await _makeHttpRequest(apiUrl);
      
      if (response == null) {
        return null;
      }
      
      // 解析响应数据
      return _parseFirmwareData(response, baseUrl, firmwarePath);
    } catch (e) {
      print('获取固件版本信息失败: $e');
      return null;
    }
  }

  /// 发送HTTP请求
  static Future<dynamic> _makeHttpRequest(String url) async {
    try {
      // 使用基础的http客户端
      final httpClient = HttpClient();
      
      final request = await httpClient.getUrl(Uri.parse(url));
      final response = await request.close();
      
      if (response.statusCode != 200) {
        return null;
      }
      
      final responseBody = await response.transform(utf8.decoder).join();
      return jsonDecode(responseBody);
    } catch (e) {
      print('HTTP请求失败: $e');
      return null;
    }
  }

  /// 解析固件数据
  static FirmwareVersionInfo? _parseFirmwareData(
    dynamic data, 
    String baseUrl, 
    String firmwarePath
  ) {
    if (data == null || data['list'] == null) {
      return null;
    }
    
    final versionList = data['list'] as List;
    int? maxVersionNum;
    String? latestFileName;

    for (var item in versionList) {
      if (item is Map && item.containsKey('n')) {
        final fileName = item['n'] as String;
        try {
          // 解析版本号 - 假设文件名格式为 "something-version.extension"
          final versionMatch = _extractVersionFromFileName(fileName);
          
          if (versionMatch != null) {
            final versionNum = int.parse(versionMatch);
            
            if (maxVersionNum == null || versionNum > maxVersionNum) {
              maxVersionNum = versionNum;
              latestFileName = fileName;
            }
          }
        } catch (e) {
          // 解析失败跳过
          continue;
        }
      }
    }

    if (latestFileName != null && maxVersionNum != null) {
      // 构建下载URL
      final downloadUrl = '$baseUrl/${firmwarePath.replaceFirst('/', '')}$latestFileName';
      
      return FirmwareVersionInfo(
        version: maxVersionNum.toString(),
        fileName: latestFileName,
        downloadUrl: downloadUrl,
      );
    }
    
    return null;
  }

  /// 从文件名中提取版本号
  static String? _extractVersionFromFileName(String fileName) {
    // 多种可能的文件名格式处理
    final patterns = [
      // 格式: something-123.bin
      RegExp(r'-(\d+)\.'),
      // 格式: v123.bin
      RegExp(r'v(\d+)\.'),
      // 格式: firmware_123.bin
      RegExp(r'_(\d+)\.'),
    ];
    
    for (final pattern in patterns) {
      final match = pattern.firstMatch(fileName);
      if (match != null && match.groupCount >= 1) {
        return match.group(1);
      }
    }
    
    return null;
  }
}