import 'package:webdav_client/webdav_client.dart';
import 'package:shared_preferences/shared_preferences.dart';

class WebDAVService {
  static const String _keyBaseUrl = 'webdav_base_url';
  static const String _keyUsername = 'webdav_username';
  static const String _keyPassword = 'webdav_password';

  static WebDAVService? _instance;
  static WebDAVService get instance => _instance ??= WebDAVService._();

  WebDAVService._();

  WebDAVClient? _client;
  String? _baseUrl;

  bool get isConnected => _client != null;

  // 保存凭据
  Future<void> saveCredentials(
      String baseUrl, String username, String password) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setString(_keyBaseUrl, baseUrl);
    await prefs.setString(_keyUsername, username);
    await prefs.setString(_keyPassword, password);
    _baseUrl = baseUrl;
    _client = WebDAVClient(
      baseUri: Uri.parse(baseUrl),
      credentials: '$username:$password',
    );
  }

  // 加载已保存的凭据
  Future<bool> loadCredentials() async {
    final prefs = await SharedPreferences.getInstance();
    final baseUrl = prefs.getString(_keyBaseUrl);
    final username = prefs.getString(_keyUsername);
    final password = prefs.getString(_keyPassword);
    if (baseUrl != null && username != null && password != null) {
      _baseUrl = baseUrl;
      _client = WebDAVClient(
        baseUri: Uri.parse(baseUrl),
        credentials: '$username:$password',
      );
      return true;
    }
    return false;
  }

  // 清除凭据
  Future<void> clearCredentials() async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.remove(_keyBaseUrl);
    await prefs.remove(_keyUsername);
    await prefs.remove(_keyPassword);
    _client = null;
    _baseUrl = null;
  }

  // 获取音乐文件列表（仅 .mp3 .flac .m4a .ape .wav）
  Future<List<WebDAVFileItem>> getMusicFiles({String path = '/'}) async {
    if (_client == null) throw Exception('WebDAV 未连接');

    final items = await _client!.listAll(recursive: true);
    final musicExtensions = ['.mp3', '.flac', '.m4a', '.ape', '.wav', '.opus'];

    return items
        .where((item) =>
            item.isFile &&
            musicExtensions.any((ext) => item.path.toLowerCase().endsWith(ext)))
        .map((item) => WebDAVFileItem(
              path: item.path,
              name: item.path.split('/').last,
              size: item.size,
              modified: item.modified,
            ))
        .toList();
  }

  // 获取文件的完整下载 URL（用于播放）
  String getFileUrl(String path) {
    if (_baseUrl == null) throw Exception('WebDAV 未配置');
    // 确保 baseUrl 末尾有 '/'
    final base = _baseUrl!.endsWith('/') ? _baseUrl! : '$_baseUrl/';
    // 去掉路径开头的 '/'
    final cleanPath = path.startsWith('/') ? path.substring(1) : path;
    return '$base$cleanPath';
  }
}

class WebDAVFileItem {
  final String path;
  final String name;
  final int? size;
  final DateTime? modified;

  WebDAVFileItem({
    required this.path,
    required this.name,
    this.size,
    this.modified,
  });
}