fix: resolve flutter analyze errors - remove leaked code, fix method calls, cleanup imports

lib/features/auth/presentation/login_screen.dart

@@ -1,18 +1,67 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
 
-import '../../../shared/widgets/feature_placeholder.dart';
+import '../../../app/router/route_names.dart';
+import '../providers/auth_provider.dart';
 
-class LoginScreen extends StatelessWidget {
+class LoginScreen extends ConsumerWidget {
   const LoginScreen({super.key});
 
   @override
-  Widget build(BuildContext context) {
+  Widget build(BuildContext context, WidgetRef ref) {
+    final authState = ref.watch(authProvider);
+
+    ref.listen<AuthState>(authProvider, (_, next) {
+      if (next is AuthAuthenticated) {
+        context.go(RouteNames.home);
+      }
+    });
+
+    final isLoading = authState is AuthLoading;
+    final errorMsg = authState is AuthError ? authState.message : null;
+
     return Scaffold(
-      appBar: AppBar(title: const Text('Dang nhap')),
-      body: const FeaturePlaceholder(
-        title: 'Google Login',
-        description:
-            'Khung dang nhap Google OAuth cho mobile auth endpoint. Se bo sung token refresh va secure storage trong phase tiep theo.',
+      body: SafeArea(
+        child: Center(
+          child: Padding(
+            padding: const EdgeInsets.symmetric(horizontal: 32),
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                const Icon(Icons.menu_book_rounded, size: 64),
+                const SizedBox(height: 20),
+                Text('Reader App', style: Theme.of(context).textTheme.headlineMedium),
+                const SizedBox(height: 8),
+                Text(
+                  'Đọc truyện mọi lúc, mọi nơi',
+                  style: Theme.of(context).textTheme.bodyLarge,
+                ),
+                const SizedBox(height: 48),
+                if (errorMsg != null) ...[
+                  Text(errorMsg, style: const TextStyle(color: Colors.red)),
+                  const SizedBox(height: 16),
+                ],
+                FilledButton.icon(
+                  onPressed: isLoading
+                      ? null
+                      : () => ref.read(authProvider.notifier).signInWithGoogle(),
+                  icon: isLoading
+                      ? const SizedBox(
+                          width: 18,
+                          height: 18,
+                          child: CircularProgressIndicator(strokeWidth: 2),
+                        )
+                      : const Icon(Icons.login),
+                  label: const Text('Đăng nhập bằng Google'),
+                  style: FilledButton.styleFrom(
+                    minimumSize: const Size.fromHeight(52),
+                  ),
+                ),
+              ],
+            ),
+          ),
+        ),
       ),
     );
   }

lib/features/auth/providers/auth_provider.dart

@@ -0,0 +1,124 @@
+import 'package:dio/dio.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:google_sign_in/google_sign_in.dart';
+
+import '../../../core/config/app_config.dart';
+import '../../../core/models/user_model.dart';
+import '../../../core/network/providers.dart';
+import '../../../core/storage/secure_store.dart';
+
+// ─── State ────────────────────────────────────────────────────────────────────
+
+abstract class AuthState {}
+
+class AuthInitial extends AuthState {}
+
+class AuthLoading extends AuthState {}
+
+class AuthAuthenticated extends AuthState {
+  AuthAuthenticated(this.user);
+  final UserModel user;
+}
+
+class AuthUnauthenticated extends AuthState {}
+
+class AuthError extends AuthState {
+  AuthError(this.message);
+  final String message;
+}
+
+// ─── Notifier ─────────────────────────────────────────────────────────────────
+
+class AuthNotifier extends StateNotifier<AuthState> {
+  AuthNotifier(this._ref) : super(AuthInitial()) {
+    _restore();
+  }
+
+  final Ref _ref;
+
+  SecureStore get _store => _ref.read(secureStoreProvider);
+
+  final GoogleSignIn _googleSignIn = GoogleSignIn(
+    clientId: AppConfig.googleClientId.isNotEmpty ? AppConfig.googleClientId : null,
+    scopes: ['email', 'profile'],
+  );
+
+  Future<void> _restore() async {
+    final token = await _store.getAccessToken();
+    if (token != null && token.isNotEmpty) {
+      await _fetchProfile();
+    } else {
+      state = AuthUnauthenticated();
+    }
+  }
+
+  Future<void> _fetchProfile() async {
+    try {
+      final dio = _ref.read(apiClientProvider).dio;
+      final res = await dio.get('/api/user/profile');
+      state = AuthAuthenticated(UserModel.fromJson(res.data as Map<String, dynamic>));
+    } catch (_) {
+      await _store.clear();
+      state = AuthUnauthenticated();
+    }
+  }
+
+  Future<void> signInWithGoogle() async {
+    try {
+      state = AuthLoading();
+      final account = await _googleSignIn.signIn();
+      if (account == null) {
+        state = AuthUnauthenticated();
+        return;
+      }
+
+      final auth = await account.authentication;
+      final idToken = auth.idToken;
+      if (idToken == null) {
+        state = AuthError('Could not get ID token from Google');
+        return;
+      }
+
+      final dio = _ref.read(apiClientProvider).dio;
+      final res = await dio.post(
+        '/api/auth/mobile-login',
+        data: {'googleIdToken': idToken},
+      );
+
+      final data = res.data as Map<String, dynamic>;
+      await _store.setAccessToken(data['accessToken'] as String);
+      if (data['refreshToken'] != null) {
+        await _store.setRefreshToken(data['refreshToken'] as String);
+      }
+
+      state = AuthAuthenticated(
+        UserModel.fromJson(data['user'] as Map<String, dynamic>),
+      );
+    } on DioException catch (e) {
+      final msg = (e.response?.data as Map?)?['error'] ?? e.message ?? 'Login failed';
+      state = AuthError(msg.toString());
+    } catch (e) {
+      state = AuthError(e.toString());
+    }
+  }
+
+  Future<void> signOut() async {
+    await _googleSignIn.signOut();
+    await _store.clear();
+    state = AuthUnauthenticated();
+  }
+}
+
+final authProvider = StateNotifierProvider<AuthNotifier, AuthState>((ref) {
+  return AuthNotifier(ref);
+});
+
+// Conveniences
+final currentUserProvider = Provider<UserModel?>((ref) {
+  final s = ref.watch(authProvider);
+  return s is AuthAuthenticated ? s.user : null;
+});
+
+final isAuthenticatedProvider = Provider<bool>((ref) {
+  return ref.watch(authProvider) is AuthAuthenticated;
+});