Merge pull request #226 from sparcs-kaist/codex/기본-access-token-만료-시-자동-로그인-문제-수정

Fix auto logout on expired tokens

Author: happycastle114

lib/dio_provider.dart

@@ -14,6 +14,8 @@ class DioProvider {
 
   final StorageService _storageService = StorageService();
 
+  bool _isRefreshingToken = false;
+
   static BuildContext? _navigatorContext;
   static BuildContext? get navigatorContext => _navigatorContext;
 
@@ -39,8 +41,24 @@ class DioProvider {
         }
         return handler.next(options);
       },
+      // 기존 구현에서는 401 상태가 오면 바로 로그아웃을 호출하여
+      // 토큰이 만료된 경우에도 자동 로그인 상태가 해제되는 문제가 있었다.
       onError: (DioException e, handler) async {
         if (e.response?.statusCode == 401) {
+          if (!_isRefreshingToken) {
+            _isRefreshingToken = true;
+            final refreshed = await _refreshToken();
+            _isRefreshingToken = false;
+            if (refreshed) {
+              try {
+                final response = await _dio.fetch(e.requestOptions);
+                return handler.resolve(response);
+              } catch (err) {
+                // If retry fails, fall through to logout
+              }
+            }
+          }
+
           if (_navigatorContext != null) {
             try {
               Provider.of<AuthModel>(_navigatorContext!, listen: false)
@@ -60,4 +78,33 @@ class DioProvider {
       },
     ));
   }
+
+  Future<bool> _refreshToken() async {
+    final refreshToken = await _storageService.getRefreshToken();
+    if (refreshToken == null) {
+      return false;
+    }
+
+    final refreshDio = Dio(BaseOptions(baseUrl: _dio.options.baseUrl));
+    try {
+      final response = await refreshDio.post(
+        SESSION_REFRESH_URL,
+        data: {'token': refreshToken},
+      );
+
+      if (response.statusCode == 200 && response.data != null) {
+        final newAccessToken = response.data['accessToken'];
+        final newRefreshToken = response.data['refreshToken'];
+
+        if (newAccessToken != null && newRefreshToken != null) {
+          await _storageService.saveTokens(
+              accessToken: newAccessToken, refreshToken: newRefreshToken);
+          return true;
+        }
+      }
+    } catch (e) {
+      print('Error refreshing token in DioProvider: $e');
+    }
+    return false;
+  }
 }

lib/main.dart

@@ -201,8 +201,8 @@ class _OTLAppState extends State<OTLApp> {
     } catch (e) {
       print("Unexpected error refreshing token: $e");
     }
-    // TODO: 토큰 갱신 실패 시 로그아웃 처리
-    return true;
+    // Token refresh failed
+    return false;
   }
 
   void _initDeepLinks() {