re-authentication attempts are made if API returns 401

AnalogIO · Feb 13, 2022 · e01b29d · e01b29d
1 parent 911aa9f
commit e01b29d
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Showing 5 changed files with 100 additions and 31 deletions.
diff --git a/lib/cubits/authentication/authentication_cubit.dart b/lib/cubits/authentication/authentication_cubit.dart
@@ -23,7 +23,10 @@ class AuthenticationCubit extends Cubit<AuthenticationState> {
   }
 
   Future<void> authenticated(
-      String email, String passcode, String token) async {
+    String email,
+    String passcode,
+    String token,
+  ) async {
     await _storage.saveAuthenticatedUser(
       email,
       passcode,

diff --git a/lib/data/storage/secure_storage.dart b/lib/data/storage/secure_storage.dart
@@ -15,7 +15,10 @@ class SecureStorage {
   Future<bool> get hasToken async => await readToken() != null;
 
   Future<void> saveAuthenticatedUser(
-      String email, String passcode, String token) async {
+    String email,
+    String passcode,
+    String token,
+  ) async {
     await _storage.write(key: _emailKey, value: email);
     await _storage.write(key: _passcodeKey, value: passcode);
     await _storage.write(key: _tokenKey, value: token);
@@ -38,6 +41,11 @@ class SecureStorage {
     _logger.d('Email, passcode and token removed from Secure Storage');
   }
 
+  Future<void> updateToken(String token) async {
+    await _storage.write(key: _tokenKey, value: token);
+    _logger.d('Token updated in Secure Storage');
+  }
+
   Future<String?> readEmail() async {
     return _storage.read(key: _emailKey);
   }

diff --git a/lib/main.dart b/lib/main.dart
@@ -3,7 +3,6 @@ import 'package:coffeecard/base/style/theme.dart';
 import 'package:coffeecard/cubits/authentication/authentication_cubit.dart';
 import 'package:coffeecard/cubits/environment/environment_cubit.dart';
 import 'package:coffeecard/data/repositories/v1/app_config_repository.dart';
-import 'package:coffeecard/data/storage/secure_storage.dart';
 import 'package:coffeecard/service_locator.dart';
 import 'package:coffeecard/widgets/pages/splash_page.dart';
 import 'package:coffeecard/widgets/routers/splash_router.dart';
@@ -18,11 +17,6 @@ void main() {
 class App extends StatelessWidget {
   final _navigatorKey = GlobalKey<NavigatorState>();
 
-  AuthenticationCubit _createAuthenticationCubit(BuildContext _) {
-    final storage = sl.get<SecureStorage>();
-    return AuthenticationCubit(storage)..appStarted();
-  }
-
   EnvironmentCubit _createEnvironmentCubit(BuildContext _) {
     final repo = sl.get<AppConfigRepository>();
     return EnvironmentCubit(repo)..getConfig();
@@ -32,7 +26,7 @@ class App extends StatelessWidget {
   Widget build(BuildContext context) {
     return MultiBlocProvider(
       providers: [
-        BlocProvider(create: _createAuthenticationCubit),
+        BlocProvider.value(value: sl<AuthenticationCubit>()..appStarted()),
         BlocProvider(create: _createEnvironmentCubit),
       ],
       child: SplashRouter(

diff --git a/lib/service_locator.dart b/lib/service_locator.dart
@@ -1,4 +1,5 @@
 import 'package:chopper/chopper.dart';
+import 'package:coffeecard/cubits/authentication/authentication_cubit.dart';
 import 'package:coffeecard/data/api/coffee_card_api_constants.dart';
 import 'package:coffeecard/data/api/interceptors/authentication_interceptor.dart';
 import 'package:coffeecard/data/repositories/shiftplanning/opening_hours_repository.dart';
@@ -38,15 +39,19 @@ void configureServices() {
       CoffeecardApi.create(),
       CoffeecardApiV2.create(),
     ],
-    authenticator: ReactivationAuthenticator(sl.get<SecureStorage>()),
+    authenticator: ReactivationAuthenticator(
+      sl.get<SecureStorage>(),
+    ),
   );
 
   final _shiftplanningChopper = ChopperClient(
     baseUrl: CoffeeCardApiConstants.shiftyUrl,
     // TODO load the url from config files
     converter: $JsonSerializableConverter(),
     services: [ShiftplanningApi.create()],
-    authenticator: ReactivationAuthenticator(sl.get<SecureStorage>()),
+    authenticator: ReactivationAuthenticator(
+      sl.get<SecureStorage>(),
+    ),
   );
 
   sl.registerSingleton<CoffeecardApi>(
@@ -94,4 +99,9 @@ void configureServices() {
   sl.registerFactory<OpeningHoursRepository>(
     () => OpeningHoursRepository(sl<ShiftplanningApi>(), sl<Logger>()),
   );
+
+  // Cubits
+  sl.registerSingleton<AuthenticationCubit>(
+    AuthenticationCubit(sl.get<SecureStorage>()),
+  );
 }
diff --git a/lib/utils/reactivation_authenticator.dart b/lib/utils/reactivation_authenticator.dart
@@ -1,36 +1,90 @@
 import 'dart:async';
 
 import 'package:chopper/chopper.dart';
+import 'package:coffeecard/cubits/authentication/authentication_cubit.dart';
 import 'package:coffeecard/data/repositories/v1/account_repository.dart';
 import 'package:coffeecard/data/storage/secure_storage.dart';
+import 'package:coffeecard/service_locator.dart';
 
 class ReactivationAuthenticator extends Authenticator {
   final SecureStorage secureStorage;
-  //final AccountRepository _accountRepository;
+  DateTime? tokenRefreshedAt;
+  final Duration debounce = const Duration(seconds: 10);
+  int _retryCount = 0;
+  final int _retryLimit = 1;
 
   ReactivationAuthenticator(this.secureStorage);
 
+  bool _canRefreshToken() {
+    if (tokenRefreshedAt == null) {
+      return true;
+    } else {
+      return tokenRefreshedAt!.difference(DateTime.now()) < debounce;
+    }
+  }
+
+  Future<void> _evict() async {
+    final authenticationCubit = sl.get<AuthenticationCubit>();
+    await authenticationCubit.unauthenticated();
+  }
+
   @override
-  FutureOr<Request?> authenticate(Request request, Response response) async {
+  FutureOr<Request?> authenticate(
+    Request request,
+    Response response, [
+    Request? originalRequest,
+  ]) async {
     if (response.statusCode == 401) {
-      final email = await secureStorage.readEmail();
-      final passcode = await secureStorage.readPasscode();
-
-      if (email != null && passcode != null) {
-        /*final either = await _accountRepository.login(email, passcode);
-
-        if (either.isRight) {
-          final Map<String, String> updatedHeaders =
-              Map<String, String>.of(request.headers);
-
-          final newToken = 'Bearer ${either.right.token}';
-          updatedHeaders.update(
-            'Authorization',
-            (String _) => newToken,
-            ifAbsent: () => newToken,
-          );
-          return request.copyWith(headers: updatedHeaders);
-        } */
+      // sign the user out
+      if (_retryCount > _retryLimit) {
+        _evict();
+        return null;
+      }
+
+      // avoid refreshing the token multiple times if requests happen at the same time
+      if (!_canRefreshToken()) {
+        return null;
+      }
+
+      return await refreshToken(request, response);
+    }
+    return null;
+  }
+
+  Future<Request?> refreshToken(
+    Request request,
+    Response response,
+  ) async {
+    _retryCount++;
+
+    final accountRepository = sl.get<AccountRepository>();
+    final email = await secureStorage.readEmail();
+    final passcode = await secureStorage.readPasscode();
+
+    if (email != null && passcode != null) {
+      // this call may return 401 which triggers a recursive call
+      final either = await accountRepository.login(
+        email,
+        passcode,
+      );
+
+      if (either.isRight) {
+        tokenRefreshedAt = DateTime.now();
+        _retryCount = 0;
+
+        final Map<String, String> updatedHeaders =
+            Map<String, String>.of(request.headers);
+
+        final token = either.right.token;
+        final bearerToken = 'Bearer ${either.right.token}';
+        await secureStorage.updateToken(token);
+
+        updatedHeaders.update(
+          'Authorization',
+          (String _) => bearerToken,
+          ifAbsent: () => bearerToken,
+        );
+        return request.copyWith(headers: updatedHeaders);
       }
     }
     return null;