import 'package:flutter/foundation.dart';
import 'package:dio/dio.dart';
import 'package:shared_preferences/shared_preferences.dart';

/// 用户认证服务 —— 登录 / 登出 / Token 持久化
class AuthService extends ChangeNotifier {
  // --------------- 状态 ---------------
  String _token = '';
  String _username = '';
  String _displayName = '';
  String _avatarUrl = '';
  bool _isLoading = false;

  String get token => _token;
  String get username => _username;
  String get displayName => _displayName.isNotEmpty ? _displayName : _username;
  String get avatarUrl => _avatarUrl;
  bool get isLoggedIn => _token.isNotEmpty;
  bool get isLoading => _isLoading;

  // --------------- Dio (内部使用，不依赖 ApiService 避免循环) ---------------
  final Dio _dio = Dio(BaseOptions(
    baseUrl: 'http://10.0.2.2:8080/api',
    connectTimeout: const Duration(seconds: 15),
    receiveTimeout: const Duration(seconds: 15),
  ));

  // --------------- 初始化（app 启动时恢复 session） ---------------
  Future<void> init() async {
    final prefs = await SharedPreferences.getInstance();
    _token = prefs.getString('token') ?? '';
    _username = prefs.getString('username') ?? '';
    _displayName = prefs.getString('displayName') ?? '';
    _avatarUrl = prefs.getString('avatarUrl') ?? '';
    notifyListeners();
  }

  // --------------- 登录 ---------------
  Future<bool> login(String username, String password) async {
    _isLoading = true;
    notifyListeners();

    try {
      final res = await _dio.post('/base/auth/login', data: {
        'username': username,
        'password': password,
      });

      // 兼容两种响应格式
      final data = res.data;
      if (data is Map && (data['code'] == 200 || data['code'] == 0)) {
        final payload = data['data'] ?? data;
        _token = payload is String ? payload : (payload['token'] ?? payload['accessToken'] ?? '').toString();
        _username = payload is Map ? (payload['username'] ?? username).toString() : username;
        _displayName = payload is Map ? (payload['displayName'] ?? payload['nickName'] ?? '').toString() : '';
        _avatarUrl = payload is Map ? (payload['avatar'] ?? '').toString() : '';

        await _persist();
        _isLoading = false;
        notifyListeners();
        return true;
      }
    } catch (e) {
      debugPrint('Login error: $e');
    }

    _isLoading = false;
    notifyListeners();
    return false;
  }

  // --------------- 登出 ---------------
  Future<void> logout() async {
    _token = '';
    _username = '';
    _displayName = '';
    _avatarUrl = '';

    final prefs = await SharedPreferences.getInstance();
    await prefs.remove('token');
    await prefs.remove('username');
    await prefs.remove('displayName');
    await prefs.remove('avatarUrl');

    notifyListeners();
  }

  // --------------- 刷新用户信息 ---------------
  Future<void> refreshProfile() async {
    if (_token.isEmpty) return;
    try {
      final res = await _dio.get(
        '/base/user/info',
        options: Options(headers: {'Authorization': 'Bearer $_token'}),
      );
      final data = res.data;
      if (data is Map && (data['code'] == 200 || data['code'] == 0)) {
        final payload = data['data'] ?? data;
        if (payload is Map) {
          _displayName = (payload['displayName'] ?? payload['nickName'] ?? _displayName).toString();
          _avatarUrl = (payload['avatar'] ?? _avatarUrl).toString();
          await _persist();
          notifyListeners();
        }
      }
    } catch (e) {
      debugPrint('refreshProfile error: $e');
    }
  }

  // --------------- 持久化 ---------------
  Future<void> _persist() async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setString('token', _token);
    await prefs.setString('username', _username);
    await prefs.setString('displayName', _displayName);
    await prefs.setString('avatarUrl', _avatarUrl);
  }
}