implemented auth repository and service in dart (JWT)

backend-dart/lib/application/repository/in_memory_auth_repository_impl.dart

@@ -0,0 +1,81 @@
+import 'package:backend_dart/domain/errors/app_error.dart';
+import 'package:backend_dart/domain/errors/error.dart';
+import 'package:backend_dart/domain/repository/auth_repository.dart';
+import 'package:dart_jsonwebtoken/dart_jsonwebtoken.dart';
+import 'package:fpdart/fpdart.dart';
+
+class InMemoryAuthRepositoryImpl implements AuthRepository {
+  final String secretKey;
+  final Map<String, String> sessionCache = {};
+  final Duration tokenExpiry;
+
+  InMemoryAuthRepositoryImpl({
+    required this.secretKey,
+    this.tokenExpiry = const Duration(hours: 24),
+  });
+
+  @override
+  TaskEither<IError, String> generateToken(String userId) {
+    return TaskEither.tryCatch(
+      () async {
+        final jwt = JWT({
+          'userId': userId,
+          'exp': DateTime.now().add(tokenExpiry).millisecondsSinceEpoch,
+        });
+        final token = jwt.sign(SecretKey(secretKey));
+
+        // Add to cache
+        sessionCache[token] = userId;
+
+        return token;
+      },
+      (error, _) =>
+          AppError.authenticationError(message: 'Failed to generate token'),
+    );
+  }
+
+  @override
+  TaskEither<IError, String> validateToken(String token) {
+    return TaskEither.tryCatch(
+      () async {
+        final jwt = JWT.verify(token, SecretKey(secretKey));
+
+        // Extract userId
+        final userId = jwt.payload['userId'] as String?;
+
+        if (userId == null) {
+          throw AppError.authenticationError(
+              message: 'Invalid token payload: userId not found');
+        }
+
+        // Check if the token exists in the cache
+        if (!sessionCache.containsKey(token)) {
+          throw AppError.authenticationError(
+              message: 'Token not found in cache');
+        }
+
+        return userId;
+      },
+      (error, _) => error is AppError
+          ? error
+          : AppError.authenticationError(message: 'Failed to validate token'),
+    );
+  }
+
+  @override
+  TaskEither<IError, void> revokeToken(String token) {
+    return TaskEither.tryCatch(
+      () async {
+        if (sessionCache.containsKey(token)) {
+          sessionCache.remove(token);
+          return;
+        } else {
+          throw AppError.authenticationError(message: 'Token not found');
+        }
+      },
+      (error, _) => error is AppError
+          ? error
+          : AppError.authenticationError(message: 'Failed to revoke token'),
+    );
+  }
+}

backend-dart/lib/application/repository/project_repository_impl.dart

@@ -1,6 +1,6 @@
 import 'package:backend_dart/domain/data/database.dart';
 import 'package:backend_dart/domain/entities/project.dart';
-import 'package:backend_dart/domain/interface/error.dart';
+import 'package:backend_dart/domain/errors/error.dart';
 import 'package:backend_dart/domain/repository/project_repository.dart';
 import 'package:fpdart/fpdart.dart';
 

backend-dart/lib/application/repository/project_task_repository_impl.dart

@@ -1,6 +1,6 @@
 import 'package:backend_dart/domain/data/database.dart';
 import 'package:backend_dart/domain/entities/project_task.dart';
-import 'package:backend_dart/domain/interface/error.dart';
+import 'package:backend_dart/domain/errors/error.dart';
 import 'package:backend_dart/domain/repository/project_task_repository.dart';
 import 'package:fpdart/fpdart.dart';
 

backend-dart/lib/application/repository/provider.dart

@@ -1,7 +1,9 @@
+import 'package:backend_dart/application/repository/in_memory_auth_repository_impl.dart';
 import 'package:backend_dart/application/repository/project_repository_impl.dart';
 import 'package:backend_dart/application/repository/project_task_repository_impl.dart';
 import 'package:backend_dart/application/repository/time_entry_repository_impl.dart';
 import 'package:backend_dart/application/repository/user_repository_impl.dart';
+import 'package:backend_dart/domain/repository/auth_repository.dart';
 import 'package:backend_dart/domain/repository/project_repository.dart';
 import 'package:backend_dart/domain/repository/project_task_repository.dart';
 import 'package:backend_dart/domain/repository/time_entry_repository.dart';
@@ -28,3 +30,7 @@ final timeEntryProvider = Provider<TimeEntryRepository>((ref) {
   final database = ref.read(databaseProvider);
   return TimeEntryRepositoryImpl(database);
 });
+
+final authProvider = Provider<AuthRepository>((ref) {
+  return InMemoryAuthRepositoryImpl(secretKey: "Secret");
+});

backend-dart/lib/application/repository/time_entry_repository_impl.dart

@@ -1,6 +1,6 @@
 import 'package:backend_dart/domain/data/database.dart';
 import 'package:backend_dart/domain/entities/time_entry.dart';
-import 'package:backend_dart/domain/interface/error.dart';
+import 'package:backend_dart/domain/errors/error.dart';
 import 'package:backend_dart/domain/repository/time_entry_repository.dart';
 import 'package:fpdart/fpdart.dart';
 

backend-dart/lib/application/repository/user_repository_impl.dart

@@ -1,6 +1,6 @@
 import 'package:backend_dart/domain/entities/user.dart';
 import 'package:backend_dart/domain/data/database.dart';
-import 'package:backend_dart/domain/interface/error.dart';
+import 'package:backend_dart/domain/errors/error.dart';
 import 'package:backend_dart/domain/repository/user_repository.dart';
 import 'package:fpdart/fpdart.dart';