优化

client/flutter/lib/providers/auth_provider.dart

@@ -0,0 +1,164 @@
+import 'package:flutter/material.dart';
+import 'package:sales_chat/models/user.dart';
+import 'package:sales_chat/services/api_service.dart';
+
+class AuthProvider with ChangeNotifier {
+  final ApiService _apiService;
+
+  User? _user;
+  bool _isLoading = false;
+  String? _error;
+
+  AuthProvider(this._apiService);
+
+  User? get user => _user;
+  bool get isLoading => _isLoading;
+  String? get error => _error;
+  bool get isLoggedIn => _user != null;
+  Future<bool> get isAuthenticated => _apiService.isAuthenticated;
+
+  /// 使用邮箱/用户名和密码登录。
+  /// 至少提供其中一个 [email] 或 [username]。
+  Future<bool> login({
+    String? email,
+    String? username,
+    required String password,
+  }) async {
+    _isLoading = true;
+    _error = null;
+    notifyListeners();
+
+    try {
+      final response = await _apiService.login(
+        email: email,
+        username: username,
+        password: password,
+      );
+      _user = response.user;
+      _isLoading = false;
+      notifyListeners();
+      return true;
+    } catch (e) {
+      _error = _parseError(e);
+      _isLoading = false;
+      notifyListeners();
+      return false;
+    }
+  }
+
+  /// 以访客身份登录（临时用户）。
+  Future<bool> loginAsGuest({required String nickname}) async {
+    _isLoading = true;
+    _error = null;
+    notifyListeners();
+
+    try {
+      final response = await _apiService.createTemporaryUser(nickname: nickname);
+      _user = response.user;
+      _isLoading = false;
+      notifyListeners();
+      return true;
+    } catch (e) {
+      _error = _parseError(e);
+      _isLoading = false;
+      notifyListeners();
+      return false;
+    }
+  }
+
+  /// 注册新用户。
+  Future<bool> register({
+    String? username,
+    String? email,
+    String? nickname,
+    required String password,
+  }) async {
+    _isLoading = true;
+    _error = null;
+    notifyListeners();
+
+    try {
+      final response = await _apiService.register(
+        username: username,
+        email: email,
+        nickname: nickname,
+        password: password,
+      );
+      _user = response.user;
+      _isLoading = false;
+      notifyListeners();
+      return true;
+    } catch (e) {
+      _error = _parseRegisterError(e);
+      _isLoading = false;
+      notifyListeners();
+      return false;
+    }
+  }
+
+  Future<void> logout() async {
+    _isLoading = true;
+    notifyListeners();
+
+    try {
+      await _apiService.logout();
+    } finally {
+      _user = null;
+      _isLoading = false;
+      notifyListeners();
+    }
+  }
+
+  Future<void> loadUser() async {
+    if (!await _apiService.isAuthenticated) return;
+
+    _isLoading = true;
+    notifyListeners();
+
+    try {
+      _user = await _apiService.getCurrentUser();
+    } catch (e) {
+      _user = null;
+    } finally {
+      _isLoading = false;
+      notifyListeners();
+    }
+  }
+
+  void clearError() {
+    _error = null;
+    notifyListeners();
+  }
+
+  String _parseError(dynamic e) {
+    final errStr = e.toString();
+    if (errStr.contains('401')) {
+      return 'Email/username or password incorrect';
+    } else if (errStr.contains('422') || errStr.contains('password')) {
+      return 'Email/username or password incorrect';
+    } else if (errStr.contains('timeout')) {
+      return 'Network timeout, please retry';
+    } else if (errStr.contains('SocketException')) {
+      return 'Network connection failed';
+    } else if (errStr.contains('banned')) {
+      return 'Account has been banned';
+    }
+    return 'Login failed, please retry';
+  }
+
+  String _parseRegisterError(dynamic e) {
+    final errorStr = e.toString();
+    if (errorStr.contains('exist')) {
+      return 'Username or email already exists';
+    } else if (errorStr.contains('empty')) {
+      return 'Username or email is required';
+    } else if (errorStr.contains('timeout')) {
+      return 'Network timeout, please retry';
+    } else if (errorStr.contains('SocketException')) {
+      return 'Network connection failed';
+    } else if (errorStr.contains('not allowed')) {
+      return 'Server does not allow new user registration';
+    }
+    return 'Registration failed, please retry';
+  }
+}