implemented user service (no auth!)

backend-dart/lib/application/dto/user_dto.dart

@@ -1,29 +0,0 @@
-import 'package:json_annotation/json_annotation.dart';
-
-part 'user_dto.g.dart';
-
-@JsonSerializable()
-class UserDto {
-  final String id;
-  final String name;
-  final String email;
-
-  // Optional: Füge zusätzliche Felder wie Timestamps hinzu
-  final DateTime? createdAt;
-  final DateTime? updatedAt;
-
-  UserDto({
-    required this.id,
-    required this.name,
-    required this.email,
-    this.createdAt,
-    this.updatedAt,
-  });
-
-  /// Factory-Methode zur Deserialisierung von JSON
-  factory UserDto.fromJson(Map<String, dynamic> json) =>
-      _$UserDtoFromJson(json);
-
-  /// Methode zur Serialisierung nach JSON
-  Map<String, dynamic> toJson() => _$UserDtoToJson(this);
-}

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

@@ -0,0 +1,9 @@
+import 'package:backend_dart/application/repository/user_repository_impl.dart';
+import 'package:backend_dart/domain/repository/user_repository.dart';
+import 'package:backend_dart/infrastructure/persistence/database_provider.dart';
+import 'package:riverpod/riverpod.dart';
+
+final userRepoProvider = Provider<UserRepository>((ref) {
+  final database = ref.read(databaseProvider);
+  return UserRepositoryImpl(database);
+});

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

@@ -0,0 +1,45 @@
+import 'package:backend_dart/domain/entities/user.dart';
+import 'package:backend_dart/domain/interface/database.dart';
+import 'package:backend_dart/domain/interface/error.dart';
+import 'package:backend_dart/domain/repository/user_repository.dart';
+import 'package:fpdart/fpdart.dart';
+
+class UserRepositoryImpl implements UserRepository {
+  final IDatabase database;
+  UserRepositoryImpl(this.database);
+
+  @override
+  TaskEither<IError, User> create(User user) {
+    return database.users
+        .generateId()
+        .map(
+          (id) => user.copyWith(id: id),
+        )
+        .flatMap(database.users.create);
+  }
+
+  @override
+  TaskEither<IError, User> findByEmail(String email) {
+    return database.users.findByEmail(email);
+  }
+
+  @override
+  TaskEither<IError, User> findById(String id) {
+    return database.users.findById(id);
+  }
+
+  @override
+  TaskEither<IError, User> update(User user) {
+    return database.users.update(user);
+  }
+
+  @override
+  TaskEither<IError, void> delete(String id) {
+    return database.users.delete(id);
+  }
+
+  @override
+  TaskEither<IError, List<User>> findAll() {
+    return database.users.findAll();
+  }
+}

backend-dart/lib/application/service/dto/user_dto.dart

@@ -0,0 +1,20 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+part 'user_dto.freezed.dart';
+part 'user_dto.g.dart';
+
+@freezed
+class UserDto with _$UserDto {
+  const factory UserDto({
+    String? id,
+    String? name,
+    String? email,
+    String? password,
+    DateTime? createdAt,
+    DateTime? updatedAt,
+  }) = _UserDto;
+
+  /// JSON-Serialisierung
+  factory UserDto.fromJson(Map<String, dynamic> json) =>
+      _$UserDtoFromJson(json);
+}

backend-dart/lib/application/service/dto/user_dto.freezed.dart

@@ -0,0 +1,268 @@
+// coverage:ignore-file
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// ignore_for_file: type=lint
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'user_dto.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+T _$identity<T>(T value) => value;
+
+final _privateConstructorUsedError = UnsupportedError(
+    'It seems like you constructed your class using `MyClass._()`. This constructor is only meant to be used by freezed and you are not supposed to need it nor use it.\nPlease check the documentation here for more information: https://github.com/rrousselGit/freezed#adding-getters-and-methods-to-our-models');
+
+UserDto _$UserDtoFromJson(Map<String, dynamic> json) {
+  return _UserDto.fromJson(json);
+}
+
+/// @nodoc
+mixin _$UserDto {
+  String? get id => throw _privateConstructorUsedError;
+  String? get name => throw _privateConstructorUsedError;
+  String? get email => throw _privateConstructorUsedError;
+  String? get password => throw _privateConstructorUsedError;
+  DateTime? get createdAt => throw _privateConstructorUsedError;
+  DateTime? get updatedAt => throw _privateConstructorUsedError;
+
+  /// Serializes this UserDto to a JSON map.
+  Map<String, dynamic> toJson() => throw _privateConstructorUsedError;
+
+  /// Create a copy of UserDto
+  /// with the given fields replaced by the non-null parameter values.
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  $UserDtoCopyWith<UserDto> get copyWith => throw _privateConstructorUsedError;
+}
+
+/// @nodoc
+abstract class $UserDtoCopyWith<$Res> {
+  factory $UserDtoCopyWith(UserDto value, $Res Function(UserDto) then) =
+      _$UserDtoCopyWithImpl<$Res, UserDto>;
+  @useResult
+  $Res call(
+      {String? id,
+      String? name,
+      String? email,
+      String? password,
+      DateTime? createdAt,
+      DateTime? updatedAt});
+}
+
+/// @nodoc
+class _$UserDtoCopyWithImpl<$Res, $Val extends UserDto>
+    implements $UserDtoCopyWith<$Res> {
+  _$UserDtoCopyWithImpl(this._value, this._then);
+
+  // ignore: unused_field
+  final $Val _value;
+  // ignore: unused_field
+  final $Res Function($Val) _then;
+
+  /// Create a copy of UserDto
+  /// with the given fields replaced by the non-null parameter values.
+  @pragma('vm:prefer-inline')
+  @override
+  $Res call({
+    Object? id = freezed,
+    Object? name = freezed,
+    Object? email = freezed,
+    Object? password = freezed,
+    Object? createdAt = freezed,
+    Object? updatedAt = freezed,
+  }) {
+    return _then(_value.copyWith(
+      id: freezed == id
+          ? _value.id
+          : id // ignore: cast_nullable_to_non_nullable
+              as String?,
+      name: freezed == name
+          ? _value.name
+          : name // ignore: cast_nullable_to_non_nullable
+              as String?,
+      email: freezed == email
+          ? _value.email
+          : email // ignore: cast_nullable_to_non_nullable
+              as String?,
+      password: freezed == password
+          ? _value.password
+          : password // ignore: cast_nullable_to_non_nullable
+              as String?,
+      createdAt: freezed == createdAt
+          ? _value.createdAt
+          : createdAt // ignore: cast_nullable_to_non_nullable
+              as DateTime?,
+      updatedAt: freezed == updatedAt
+          ? _value.updatedAt
+          : updatedAt // ignore: cast_nullable_to_non_nullable
+              as DateTime?,
+    ) as $Val);
+  }
+}
+
+/// @nodoc
+abstract class _$$UserDtoImplCopyWith<$Res> implements $UserDtoCopyWith<$Res> {
+  factory _$$UserDtoImplCopyWith(
+          _$UserDtoImpl value, $Res Function(_$UserDtoImpl) then) =
+      __$$UserDtoImplCopyWithImpl<$Res>;
+  @override
+  @useResult
+  $Res call(
+      {String? id,
+      String? name,
+      String? email,
+      String? password,
+      DateTime? createdAt,
+      DateTime? updatedAt});
+}
+
+/// @nodoc
+class __$$UserDtoImplCopyWithImpl<$Res>
+    extends _$UserDtoCopyWithImpl<$Res, _$UserDtoImpl>
+    implements _$$UserDtoImplCopyWith<$Res> {
+  __$$UserDtoImplCopyWithImpl(
+      _$UserDtoImpl _value, $Res Function(_$UserDtoImpl) _then)
+      : super(_value, _then);
+
+  /// Create a copy of UserDto
+  /// with the given fields replaced by the non-null parameter values.
+  @pragma('vm:prefer-inline')
+  @override
+  $Res call({
+    Object? id = freezed,
+    Object? name = freezed,
+    Object? email = freezed,
+    Object? password = freezed,
+    Object? createdAt = freezed,
+    Object? updatedAt = freezed,
+  }) {
+    return _then(_$UserDtoImpl(
+      id: freezed == id
+          ? _value.id
+          : id // ignore: cast_nullable_to_non_nullable
+              as String?,
+      name: freezed == name
+          ? _value.name
+          : name // ignore: cast_nullable_to_non_nullable
+              as String?,
+      email: freezed == email
+          ? _value.email
+          : email // ignore: cast_nullable_to_non_nullable
+              as String?,
+      password: freezed == password
+          ? _value.password
+          : password // ignore: cast_nullable_to_non_nullable
+              as String?,
+      createdAt: freezed == createdAt
+          ? _value.createdAt
+          : createdAt // ignore: cast_nullable_to_non_nullable
+              as DateTime?,
+      updatedAt: freezed == updatedAt
+          ? _value.updatedAt
+          : updatedAt // ignore: cast_nullable_to_non_nullable
+              as DateTime?,
+    ));
+  }
+}
+
+/// @nodoc
+@JsonSerializable()
+class _$UserDtoImpl implements _UserDto {
+  const _$UserDtoImpl(
+      {this.id,
+      this.name,
+      this.email,
+      this.password,
+      this.createdAt,
+      this.updatedAt});
+
+  factory _$UserDtoImpl.fromJson(Map<String, dynamic> json) =>
+      _$$UserDtoImplFromJson(json);
+
+  @override
+  final String? id;
+  @override
+  final String? name;
+  @override
+  final String? email;
+  @override
+  final String? password;
+  @override
+  final DateTime? createdAt;
+  @override
+  final DateTime? updatedAt;
+
+  @override
+  String toString() {
+    return 'UserDto(id: $id, name: $name, email: $email, password: $password, createdAt: $createdAt, updatedAt: $updatedAt)';
+  }
+
+  @override
+  bool operator ==(Object other) {
+    return identical(this, other) ||
+        (other.runtimeType == runtimeType &&
+            other is _$UserDtoImpl &&
+            (identical(other.id, id) || other.id == id) &&
+            (identical(other.name, name) || other.name == name) &&
+            (identical(other.email, email) || other.email == email) &&
+            (identical(other.password, password) ||
+                other.password == password) &&
+            (identical(other.createdAt, createdAt) ||
+                other.createdAt == createdAt) &&
+            (identical(other.updatedAt, updatedAt) ||
+                other.updatedAt == updatedAt));
+  }
+
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  @override
+  int get hashCode =>
+      Object.hash(runtimeType, id, name, email, password, createdAt, updatedAt);
+
+  /// Create a copy of UserDto
+  /// with the given fields replaced by the non-null parameter values.
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  @override
+  @pragma('vm:prefer-inline')
+  _$$UserDtoImplCopyWith<_$UserDtoImpl> get copyWith =>
+      __$$UserDtoImplCopyWithImpl<_$UserDtoImpl>(this, _$identity);
+
+  @override
+  Map<String, dynamic> toJson() {
+    return _$$UserDtoImplToJson(
+      this,
+    );
+  }
+}
+
+abstract class _UserDto implements UserDto {
+  const factory _UserDto(
+      {final String? id,
+      final String? name,
+      final String? email,
+      final String? password,
+      final DateTime? createdAt,
+      final DateTime? updatedAt}) = _$UserDtoImpl;
+
+  factory _UserDto.fromJson(Map<String, dynamic> json) = _$UserDtoImpl.fromJson;
+
+  @override
+  String? get id;
+  @override
+  String? get name;
+  @override
+  String? get email;
+  @override
+  String? get password;
+  @override
+  DateTime? get createdAt;
+  @override
+  DateTime? get updatedAt;
+
+  /// Create a copy of UserDto
+  /// with the given fields replaced by the non-null parameter values.
+  @override
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  _$$UserDtoImplCopyWith<_$UserDtoImpl> get copyWith =>
+      throw _privateConstructorUsedError;
+}

backend-dart/lib/application/service/dto/user_dto.g.dart

@@ -6,10 +6,12 @@ part of 'user_dto.dart';
 // JsonSerializableGenerator
 // **************************************************************************
 
-UserDto _$UserDtoFromJson(Map<String, dynamic> json) => UserDto(
+_$UserDtoImpl _$$UserDtoImplFromJson(Map<String, dynamic> json) =>
-      id: json['id'] as String,
+    _$UserDtoImpl(
-      name: json['name'] as String,
+      id: json['id'] as String?,
-      email: json['email'] as String,
+      name: json['name'] as String?,
+      email: json['email'] as String?,
+      password: json['password'] as String?,
       createdAt: json['createdAt'] == null
           ? null
           : DateTime.parse(json['createdAt'] as String),
@@ -18,10 +20,12 @@ UserDto _$UserDtoFromJson(Map<String, dynamic> json) => UserDto(
           : DateTime.parse(json['updatedAt'] as String),
     );
 
-Map<String, dynamic> _$UserDtoToJson(UserDto instance) => <String, dynamic>{
+Map<String, dynamic> _$$UserDtoImplToJson(_$UserDtoImpl instance) =>
+    <String, dynamic>{
       'id': instance.id,
       'name': instance.name,
       'email': instance.email,
+      'password': instance.password,
       'createdAt': instance.createdAt?.toIso8601String(),
       'updatedAt': instance.updatedAt?.toIso8601String(),
     };

backend-dart/lib/application/service/mapper/user_dto_mapper.dart

@@ -0,0 +1,35 @@
+import 'package:backend_dart/application/service/dto/user_dto.dart';
+import 'package:backend_dart/domain/entities/user.dart';
+import 'package:backend_dart/domain/interface/error.dart';
+import 'package:backend_dart/domain/interface/mapper.dart';
+import 'package:fpdart/fpdart.dart';
+
+class UserDtoMapper implements IMapper<User, UserDto> {
+  @override
+  TaskEither<IError, UserDto> to(User entity) => TaskEither.of(UserDto(
+        id: entity.id,
+        name: entity.name,
+        email: entity.email,
+        createdAt: entity.createdAt,
+        updatedAt: entity.updatedAt,
+      ));
+  @override
+  TaskEither<IError, User> from(UserDto dto) => TaskEither.of(User(
+        id: dto.id,
+        name: dto.name,
+        email: dto.email,
+        password: dto.password,
+        createdAt: dto.createdAt,
+        updatedAt: dto.updatedAt,
+      ));
+
+  @override
+  TaskEither<IError, List<User>> listFrom(Iterable<UserDto> targets) {
+    return TaskEither.traverseList(targets.toList(), from);
+  }
+
+  @override
+  TaskEither<IError, List<UserDto>> listTo(Iterable<User> origins) {
+    return TaskEither.traverseList(origins.toList(), to);
+  }
+}

backend-dart/lib/application/service/user_service.dart

@@ -0,0 +1,88 @@
+import 'dart:convert';
+
+import 'package:backend_dart/application/service/dto/user_dto.dart';
+import 'package:backend_dart/application/service/mapper/user_dto_mapper.dart';
+import 'package:backend_dart/common/response_helpers.dart';
+import 'package:backend_dart/domain/errors/app_error.dart';
+import 'package:backend_dart/domain/interface/error.dart';
+import 'package:backend_dart/domain/repository/user_repository.dart';
+import 'package:fpdart/fpdart.dart';
+import 'package:shelf/shelf.dart';
+import 'package:shelf_router/shelf_router.dart';
+
+part 'user_service.g.dart'; // generated with 'pub run build_runner build'
+
+class UserService {
+  final UserRepository users;
+  final UserDtoMapper mapper = UserDtoMapper();
+  UserService(this.users);
+
+  @Route.get('/')
+  Future<Response> listUsers(Request request) async {
+    return users
+        .findAll()
+        .flatMap(mapper.listTo)
+        .map((users) => users.map((user) => user.toJson()).toList())
+        .match((left) => ResponseHelpers.fromError(left),
+            (right) => Response.ok(jsonEncode(right)))
+        .run();
+  }
+
+  @Route.get('/<userId>')
+  Future<Response> fetchUser(Request request, String userId) async {
+    return users
+        .findById(userId)
+        .flatMap(mapper.to)
+        .match((left) => ResponseHelpers.fromError(left),
+            (right) => ResponseHelpers.jsonOk(right.toJson()))
+        .run();
+  }
+
+  @Route.post('/')
+  Future<Response> createUser(Request request) async {
+    return TaskEither<IError, UserDto>.tryCatch(() async {
+      final json = jsonDecode(await request.readAsString());
+      final user = UserDto.fromJson(json);
+      return user;
+    }, (error, stack) {
+      return AppError.inputError(
+          message: 'Failed to create user: ${error.toString()}');
+    })
+        .flatMap(mapper.from)
+        .flatMap(users.create)
+        .flatMap(mapper.to)
+        .match((left) => ResponseHelpers.fromError(left),
+            (right) => ResponseHelpers.jsonOk(right.toJson()))
+        .run();
+  }
+
+  @Route.put('/<userId>')
+  Future<Response> updateUser(Request request, String userId) async {
+    return TaskEither<IError, UserDto>.tryCatch(() async {
+      final json = jsonDecode(await request.readAsString());
+      final user = UserDto.fromJson(json);
+      return user;
+    }, (error, stack) {
+      return AppError.inputError(
+          message: 'Failed to update user: ${error.toString()}');
+    })
+        .flatMap(mapper.from)
+        .flatMap(users.update)
+        .flatMap(mapper.to)
+        .match((left) => ResponseHelpers.fromError(left),
+            (right) => ResponseHelpers.jsonOk(right.toJson()))
+        .run();
+  }
+
+  @Route.delete('/<userId>')
+  Future<Response> deleteUser(Request request, String userId) async {
+    return users
+        .delete(userId)
+        .match((left) => ResponseHelpers.fromError(left),
+            (right) => Response.ok('user deleted'))
+        .run();
+  }
+
+  // Create router using the generate function defined in 'userservice.g.dart'.
+  Router get router => _$UserServiceRouter(this);
+}

backend-dart/lib/application/service/user_service.g.dart

@@ -18,5 +18,20 @@ Router _$UserServiceRouter(UserService service) {
     r'/<userId>',
     service.fetchUser,
   );
+  router.add(
+    'POST',
+    r'/',
+    service.createUser,
+  );
+  router.add(
+    'PUT',
+    r'/<userId>',
+    service.updateUser,
+  );
+  router.add(
+    'DELETE',
+    r'/<userId>',
+    service.deleteUser,
+  );
   return router;
 }

backend-dart/lib/application/service/user_service_provider.dart

@@ -0,0 +1,8 @@
+import 'package:backend_dart/application/repository/provider.dart';
+import 'package:backend_dart/application/service/user_service.dart';
+import 'package:riverpod/riverpod.dart';
+
+final userServiceProvider = Provider<UserService>((ref) {
+  final database = ref.read(userRepoProvider);
+  return UserService(database);
+});

backend-dart/lib/application/user_service/user_service.dart

@@ -1,27 +0,0 @@
-import 'package:backend_dart/infrastructure/persistence/database.dart';
-import 'package:shelf/shelf.dart';
-import 'package:shelf_router/shelf_router.dart';
-
-part 'user_service.g.dart'; // generated with 'pub run build_runner build'
-
-class UserService {
-  final Database database;
-  UserService(this.database);
-
-  @Route.get('/')
-  Future<Response> listUsers(Request request) async {
-    return Response.ok('["user1"]');
-  }
-
-  @Route.get('/<userId>')
-  Future<Response> fetchUser(Request request, String userId) async {
-    final result = await database.users.findById(userId);
-    if (result != null) {
-      return Response.ok(result);
-    }
-    return Response.notFound('no such user');
-  }
-
-  // Create router using the generate function defined in 'userservice.g.dart'.
-  Router get router => _$UserServiceRouter(this);
-}

backend-dart/lib/application/user_service/user_service_provider.dart

@@ -1,8 +0,0 @@
-import 'package:backend_dart/application/user_service/user_service.dart';
-import 'package:backend_dart/infrastructure/persistence/database_provider.dart';
-import 'package:riverpod/riverpod.dart';
-
-final userServiceProvider = Provider<UserService>((ref) {
-  final database = ref.read(databaseProvider);
-  return UserService(database);
-});

backend-dart/lib/common/error_on_null.dart

@@ -0,0 +1,8 @@
+import 'package:backend_dart/domain/interface/error.dart';
+import 'package:fpdart/fpdart.dart';
+
+TaskEither<IError, T> Function(T?) errorOnNull<T>(IError error) {
+  return (T? value) {
+    return value != null ? TaskEither.of(value) : TaskEither.left(error);
+  };
+}

backend-dart/lib/common/response_helpers.dart

@@ -0,0 +1,84 @@
+import 'dart:convert';
+import 'package:backend_dart/domain/errors/error_code.dart';
+import 'package:backend_dart/domain/interface/error.dart';
+import 'package:shelf/shelf.dart';
+
+class ResponseHelpers {
+  /// Sendet eine JSON-Antwort mit einem 200-Statuscode
+  static Response jsonOk(Map<String, dynamic> data) {
+    return Response.ok(
+      jsonEncode(data),
+      headers: {'Content-Type': 'application/json'},
+    );
+  }
+
+  /// Sendet eine JSON-Antwort mit einem spezifischen Statuscode
+  static Response jsonWithStatus(Map<String, dynamic> data, int statusCode) {
+    return Response(
+      statusCode,
+      body: jsonEncode(data),
+      headers: {'Content-Type': 'application/json'},
+    );
+  }
+
+  /// Sendet eine JSON-Antwort für einen Fehler (z. B. 404 oder 500)
+  static Response jsonError(String message, {int statusCode = 500}) {
+    return Response(
+      statusCode,
+      body: jsonEncode({'error': message}),
+      headers: {'Content-Type': 'application/json'},
+    );
+  }
+
+  /// Sendet eine einfache Textantwort
+  static Response textResponse(String message, {int statusCode = 200}) {
+    return Response(
+      statusCode,
+      body: message,
+      headers: {'Content-Type': 'text/plain'},
+    );
+  }
+
+  static Response fromError(IError error) {
+    // Print error to console
+    print('Error: ${error.code.name} - ${error.message}');
+    //print(error.stackTrace);
+    return Response(
+      mapErrorCodeToHttpStatus(error.code),
+      body: jsonEncode({
+        'code': error.code.name,
+        'error': error.message,
+        'details': error.details,
+      }),
+      headers: {'Content-Type': 'application/json'},
+    );
+  }
+}
+
+int mapErrorCodeToHttpStatus(ErrorCode errorCode) {
+  switch (errorCode) {
+    case ErrorCode.networkError:
+      return 503; // Service Unavailable
+    case ErrorCode.validationError:
+    case ErrorCode.inputError:
+      return 400; // Bad Request
+    case ErrorCode.unexpectedError:
+    case ErrorCode.internalError:
+    case ErrorCode.databaseError:
+      return 500; // Internal Server Error
+    case ErrorCode.authenticationError:
+      return 401; // Unauthorized
+    case ErrorCode.permissionDenied:
+      return 403; // Forbidden
+    case ErrorCode.notFound:
+      return 404; // Not Found
+    case ErrorCode.mappingError:
+    case ErrorCode.outputError:
+      return 422; // Unprocessable Entity
+    case ErrorCode.exception:
+    case ErrorCode.unknownError:
+      return 520; // Unknown Error (Custom)
+    default:
+      return 500; // Fallback: Internal Server Error
+  }
+}

backend-dart/lib/domain/data/user_data_source.dart

@@ -0,0 +1,18 @@
+import 'package:backend_dart/domain/interface/error.dart';
+import 'package:fpdart/fpdart.dart';
+
+abstract class UserDataSource<T> {
+  TaskEither<IError, T> create(T user);
+
+  TaskEither<IError, T> findByEmail(String email);
+
+  TaskEither<IError, T> findById(String id);
+
+  TaskEither<IError, T> update(T user);
+
+  TaskEither<IError, void> delete(String id);
+
+  TaskEither<IError, List<T>> findAll();
+
+  TaskEither<IError,String> generateId();
+}

backend-dart/lib/domain/entities/user.dart

@@ -1,14 +1,13 @@
 import 'package:freezed_annotation/freezed_annotation.dart';
 
 part 'user.freezed.dart';
-part 'user.g.dart';
 
 @freezed
 class User with _$User {
   const factory User({
-    required String id,
+    String? id,
-    required String name,
+    String? name,
-    required String email,
+    String? email,
     String? password,
     DateTime? createdAt,
     DateTime? updatedAt,

backend-dart/lib/domain/entities/user.freezed.dart

@@ -0,0 +1,247 @@
+// coverage:ignore-file
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// ignore_for_file: type=lint
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'user.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+T _$identity<T>(T value) => value;
+
+final _privateConstructorUsedError = UnsupportedError(
+    'It seems like you constructed your class using `MyClass._()`. This constructor is only meant to be used by freezed and you are not supposed to need it nor use it.\nPlease check the documentation here for more information: https://github.com/rrousselGit/freezed#adding-getters-and-methods-to-our-models');
+
+/// @nodoc
+mixin _$User {
+  String? get id => throw _privateConstructorUsedError;
+  String? get name => throw _privateConstructorUsedError;
+  String? get email => throw _privateConstructorUsedError;
+  String? get password => throw _privateConstructorUsedError;
+  DateTime? get createdAt => throw _privateConstructorUsedError;
+  DateTime? get updatedAt => throw _privateConstructorUsedError;
+
+  /// Create a copy of User
+  /// with the given fields replaced by the non-null parameter values.
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  $UserCopyWith<User> get copyWith => throw _privateConstructorUsedError;
+}
+
+/// @nodoc
+abstract class $UserCopyWith<$Res> {
+  factory $UserCopyWith(User value, $Res Function(User) then) =
+      _$UserCopyWithImpl<$Res, User>;
+  @useResult
+  $Res call(
+      {String? id,
+      String? name,
+      String? email,
+      String? password,
+      DateTime? createdAt,
+      DateTime? updatedAt});
+}
+
+/// @nodoc
+class _$UserCopyWithImpl<$Res, $Val extends User>
+    implements $UserCopyWith<$Res> {
+  _$UserCopyWithImpl(this._value, this._then);
+
+  // ignore: unused_field
+  final $Val _value;
+  // ignore: unused_field
+  final $Res Function($Val) _then;
+
+  /// Create a copy of User
+  /// with the given fields replaced by the non-null parameter values.
+  @pragma('vm:prefer-inline')
+  @override
+  $Res call({
+    Object? id = freezed,
+    Object? name = freezed,
+    Object? email = freezed,
+    Object? password = freezed,
+    Object? createdAt = freezed,
+    Object? updatedAt = freezed,
+  }) {
+    return _then(_value.copyWith(
+      id: freezed == id
+          ? _value.id
+          : id // ignore: cast_nullable_to_non_nullable
+              as String?,
+      name: freezed == name
+          ? _value.name
+          : name // ignore: cast_nullable_to_non_nullable
+              as String?,
+      email: freezed == email
+          ? _value.email
+          : email // ignore: cast_nullable_to_non_nullable
+              as String?,
+      password: freezed == password
+          ? _value.password
+          : password // ignore: cast_nullable_to_non_nullable
+              as String?,
+      createdAt: freezed == createdAt
+          ? _value.createdAt
+          : createdAt // ignore: cast_nullable_to_non_nullable
+              as DateTime?,
+      updatedAt: freezed == updatedAt
+          ? _value.updatedAt
+          : updatedAt // ignore: cast_nullable_to_non_nullable
+              as DateTime?,
+    ) as $Val);
+  }
+}
+
+/// @nodoc
+abstract class _$$UserImplCopyWith<$Res> implements $UserCopyWith<$Res> {
+  factory _$$UserImplCopyWith(
+          _$UserImpl value, $Res Function(_$UserImpl) then) =
+      __$$UserImplCopyWithImpl<$Res>;
+  @override
+  @useResult
+  $Res call(
+      {String? id,
+      String? name,
+      String? email,
+      String? password,
+      DateTime? createdAt,
+      DateTime? updatedAt});
+}
+
+/// @nodoc
+class __$$UserImplCopyWithImpl<$Res>
+    extends _$UserCopyWithImpl<$Res, _$UserImpl>
+    implements _$$UserImplCopyWith<$Res> {
+  __$$UserImplCopyWithImpl(_$UserImpl _value, $Res Function(_$UserImpl) _then)
+      : super(_value, _then);
+
+  /// Create a copy of User
+  /// with the given fields replaced by the non-null parameter values.
+  @pragma('vm:prefer-inline')
+  @override
+  $Res call({
+    Object? id = freezed,
+    Object? name = freezed,
+    Object? email = freezed,
+    Object? password = freezed,
+    Object? createdAt = freezed,
+    Object? updatedAt = freezed,
+  }) {
+    return _then(_$UserImpl(
+      id: freezed == id
+          ? _value.id
+          : id // ignore: cast_nullable_to_non_nullable
+              as String?,
+      name: freezed == name
+          ? _value.name
+          : name // ignore: cast_nullable_to_non_nullable
+              as String?,
+      email: freezed == email
+          ? _value.email
+          : email // ignore: cast_nullable_to_non_nullable
+              as String?,
+      password: freezed == password
+          ? _value.password
+          : password // ignore: cast_nullable_to_non_nullable
+              as String?,
+      createdAt: freezed == createdAt
+          ? _value.createdAt
+          : createdAt // ignore: cast_nullable_to_non_nullable
+              as DateTime?,
+      updatedAt: freezed == updatedAt
+          ? _value.updatedAt
+          : updatedAt // ignore: cast_nullable_to_non_nullable
+              as DateTime?,
+    ));
+  }
+}
+
+/// @nodoc
+
+class _$UserImpl implements _User {
+  const _$UserImpl(
+      {this.id,
+      this.name,
+      this.email,
+      this.password,
+      this.createdAt,
+      this.updatedAt});
+
+  @override
+  final String? id;
+  @override
+  final String? name;
+  @override
+  final String? email;
+  @override
+  final String? password;
+  @override
+  final DateTime? createdAt;
+  @override
+  final DateTime? updatedAt;
+
+  @override
+  String toString() {
+    return 'User(id: $id, name: $name, email: $email, password: $password, createdAt: $createdAt, updatedAt: $updatedAt)';
+  }
+
+  @override
+  bool operator ==(Object other) {
+    return identical(this, other) ||
+        (other.runtimeType == runtimeType &&
+            other is _$UserImpl &&
+            (identical(other.id, id) || other.id == id) &&
+            (identical(other.name, name) || other.name == name) &&
+            (identical(other.email, email) || other.email == email) &&
+            (identical(other.password, password) ||
+                other.password == password) &&
+            (identical(other.createdAt, createdAt) ||
+                other.createdAt == createdAt) &&
+            (identical(other.updatedAt, updatedAt) ||
+                other.updatedAt == updatedAt));
+  }
+
+  @override
+  int get hashCode =>
+      Object.hash(runtimeType, id, name, email, password, createdAt, updatedAt);
+
+  /// Create a copy of User
+  /// with the given fields replaced by the non-null parameter values.
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  @override
+  @pragma('vm:prefer-inline')
+  _$$UserImplCopyWith<_$UserImpl> get copyWith =>
+      __$$UserImplCopyWithImpl<_$UserImpl>(this, _$identity);
+}
+
+abstract class _User implements User {
+  const factory _User(
+      {final String? id,
+      final String? name,
+      final String? email,
+      final String? password,
+      final DateTime? createdAt,
+      final DateTime? updatedAt}) = _$UserImpl;
+
+  @override
+  String? get id;
+  @override
+  String? get name;
+  @override
+  String? get email;
+  @override
+  String? get password;
+  @override
+  DateTime? get createdAt;
+  @override
+  DateTime? get updatedAt;
+
+  /// Create a copy of User
+  /// with the given fields replaced by the non-null parameter values.
+  @override
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  _$$UserImplCopyWith<_$UserImpl> get copyWith =>
+      throw _privateConstructorUsedError;
+}

backend-dart/lib/domain/errors/app_error.dart

@@ -0,0 +1,51 @@
+import 'package:backend_dart/domain/interface/error.dart';
+import 'package:freezed_annotation/freezed_annotation.dart';
+import 'error_code.dart';
+
+part 'app_error.freezed.dart';
+
+@freezed
+class AppError with _$AppError implements IError {
+  const factory AppError({
+    required ErrorCode code,
+    required String message,
+    Map<String, String>? details,
+    StackTrace? stackTrace,
+    Object? originalError,
+  }) = _AppError;
+
+  factory AppError.fromException(Exception e) {
+    return AppError(
+      code: ErrorCode.exception,
+      message: e.toString(),
+      originalError: e,
+    );
+  }
+
+  factory AppError.fromErrorCode(ErrorCode code, {String? message}) {
+    return AppError(
+        code: code,
+        message: message ?? "No message",
+        stackTrace: StackTrace.current);
+  }
+
+  factory AppError.notFound(String? message) {
+    return AppError.fromErrorCode(ErrorCode.notFound, message: message);
+  }
+
+  factory AppError.mappingError({String? message}) {
+    return AppError.fromErrorCode(ErrorCode.mappingError, message: message);
+  }
+
+  factory AppError.databaseError({String? message}) {
+    return AppError.fromErrorCode(ErrorCode.databaseError, message: message);
+  }
+
+  factory AppError.validationError({String? message}) {
+    return AppError.fromErrorCode(ErrorCode.validationError, message: message);
+  }
+
+  factory AppError.inputError({String? message}) {
+    return AppError.fromErrorCode(ErrorCode.inputError, message: message);
+  }
+}

backend-dart/lib/domain/errors/app_error.freezed.dart

@@ -0,0 +1,239 @@
+// coverage:ignore-file
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// ignore_for_file: type=lint
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'app_error.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+T _$identity<T>(T value) => value;
+
+final _privateConstructorUsedError = UnsupportedError(
+    'It seems like you constructed your class using `MyClass._()`. This constructor is only meant to be used by freezed and you are not supposed to need it nor use it.\nPlease check the documentation here for more information: https://github.com/rrousselGit/freezed#adding-getters-and-methods-to-our-models');
+
+/// @nodoc
+mixin _$AppError {
+  ErrorCode get code => throw _privateConstructorUsedError;
+  String get message => throw _privateConstructorUsedError;
+  Map<String, String>? get details => throw _privateConstructorUsedError;
+  StackTrace? get stackTrace => throw _privateConstructorUsedError;
+  Object? get originalError => throw _privateConstructorUsedError;
+
+  /// Create a copy of AppError
+  /// with the given fields replaced by the non-null parameter values.
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  $AppErrorCopyWith<AppError> get copyWith =>
+      throw _privateConstructorUsedError;
+}
+
+/// @nodoc
+abstract class $AppErrorCopyWith<$Res> {
+  factory $AppErrorCopyWith(AppError value, $Res Function(AppError) then) =
+      _$AppErrorCopyWithImpl<$Res, AppError>;
+  @useResult
+  $Res call(
+      {ErrorCode code,
+      String message,
+      Map<String, String>? details,
+      StackTrace? stackTrace,
+      Object? originalError});
+}
+
+/// @nodoc
+class _$AppErrorCopyWithImpl<$Res, $Val extends AppError>
+    implements $AppErrorCopyWith<$Res> {
+  _$AppErrorCopyWithImpl(this._value, this._then);
+
+  // ignore: unused_field
+  final $Val _value;
+  // ignore: unused_field
+  final $Res Function($Val) _then;
+
+  /// Create a copy of AppError
+  /// with the given fields replaced by the non-null parameter values.
+  @pragma('vm:prefer-inline')
+  @override
+  $Res call({
+    Object? code = null,
+    Object? message = null,
+    Object? details = freezed,
+    Object? stackTrace = freezed,
+    Object? originalError = freezed,
+  }) {
+    return _then(_value.copyWith(
+      code: null == code
+          ? _value.code
+          : code // ignore: cast_nullable_to_non_nullable
+              as ErrorCode,
+      message: null == message
+          ? _value.message
+          : message // ignore: cast_nullable_to_non_nullable
+              as String,
+      details: freezed == details
+          ? _value.details
+          : details // ignore: cast_nullable_to_non_nullable
+              as Map<String, String>?,
+      stackTrace: freezed == stackTrace
+          ? _value.stackTrace
+          : stackTrace // ignore: cast_nullable_to_non_nullable
+              as StackTrace?,
+      originalError:
+          freezed == originalError ? _value.originalError : originalError,
+    ) as $Val);
+  }
+}
+
+/// @nodoc
+abstract class _$$AppErrorImplCopyWith<$Res>
+    implements $AppErrorCopyWith<$Res> {
+  factory _$$AppErrorImplCopyWith(
+          _$AppErrorImpl value, $Res Function(_$AppErrorImpl) then) =
+      __$$AppErrorImplCopyWithImpl<$Res>;
+  @override
+  @useResult
+  $Res call(
+      {ErrorCode code,
+      String message,
+      Map<String, String>? details,
+      StackTrace? stackTrace,
+      Object? originalError});
+}
+
+/// @nodoc
+class __$$AppErrorImplCopyWithImpl<$Res>
+    extends _$AppErrorCopyWithImpl<$Res, _$AppErrorImpl>
+    implements _$$AppErrorImplCopyWith<$Res> {
+  __$$AppErrorImplCopyWithImpl(
+      _$AppErrorImpl _value, $Res Function(_$AppErrorImpl) _then)
+      : super(_value, _then);
+
+  /// Create a copy of AppError
+  /// with the given fields replaced by the non-null parameter values.
+  @pragma('vm:prefer-inline')
+  @override
+  $Res call({
+    Object? code = null,
+    Object? message = null,
+    Object? details = freezed,
+    Object? stackTrace = freezed,
+    Object? originalError = freezed,
+  }) {
+    return _then(_$AppErrorImpl(
+      code: null == code
+          ? _value.code
+          : code // ignore: cast_nullable_to_non_nullable
+              as ErrorCode,
+      message: null == message
+          ? _value.message
+          : message // ignore: cast_nullable_to_non_nullable
+              as String,
+      details: freezed == details
+          ? _value._details
+          : details // ignore: cast_nullable_to_non_nullable
+              as Map<String, String>?,
+      stackTrace: freezed == stackTrace
+          ? _value.stackTrace
+          : stackTrace // ignore: cast_nullable_to_non_nullable
+              as StackTrace?,
+      originalError:
+          freezed == originalError ? _value.originalError : originalError,
+    ));
+  }
+}
+
+/// @nodoc
+
+class _$AppErrorImpl implements _AppError {
+  const _$AppErrorImpl(
+      {required this.code,
+      required this.message,
+      final Map<String, String>? details,
+      this.stackTrace,
+      this.originalError})
+      : _details = details;
+
+  @override
+  final ErrorCode code;
+  @override
+  final String message;
+  final Map<String, String>? _details;
+  @override
+  Map<String, String>? get details {
+    final value = _details;
+    if (value == null) return null;
+    if (_details is EqualUnmodifiableMapView) return _details;
+    // ignore: implicit_dynamic_type
+    return EqualUnmodifiableMapView(value);
+  }
+
+  @override
+  final StackTrace? stackTrace;
+  @override
+  final Object? originalError;
+
+  @override
+  String toString() {
+    return 'AppError(code: $code, message: $message, details: $details, stackTrace: $stackTrace, originalError: $originalError)';
+  }
+
+  @override
+  bool operator ==(Object other) {
+    return identical(this, other) ||
+        (other.runtimeType == runtimeType &&
+            other is _$AppErrorImpl &&
+            (identical(other.code, code) || other.code == code) &&
+            (identical(other.message, message) || other.message == message) &&
+            const DeepCollectionEquality().equals(other._details, _details) &&
+            (identical(other.stackTrace, stackTrace) ||
+                other.stackTrace == stackTrace) &&
+            const DeepCollectionEquality()
+                .equals(other.originalError, originalError));
+  }
+
+  @override
+  int get hashCode => Object.hash(
+      runtimeType,
+      code,
+      message,
+      const DeepCollectionEquality().hash(_details),
+      stackTrace,
+      const DeepCollectionEquality().hash(originalError));
+
+  /// Create a copy of AppError
+  /// with the given fields replaced by the non-null parameter values.
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  @override
+  @pragma('vm:prefer-inline')
+  _$$AppErrorImplCopyWith<_$AppErrorImpl> get copyWith =>
+      __$$AppErrorImplCopyWithImpl<_$AppErrorImpl>(this, _$identity);
+}
+
+abstract class _AppError implements AppError {
+  const factory _AppError(
+      {required final ErrorCode code,
+      required final String message,
+      final Map<String, String>? details,
+      final StackTrace? stackTrace,
+      final Object? originalError}) = _$AppErrorImpl;
+
+  @override
+  ErrorCode get code;
+  @override
+  String get message;
+  @override
+  Map<String, String>? get details;
+  @override
+  StackTrace? get stackTrace;
+  @override
+  Object? get originalError;
+
+  /// Create a copy of AppError
+  /// with the given fields replaced by the non-null parameter values.
+  @override
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  _$$AppErrorImplCopyWith<_$AppErrorImpl> get copyWith =>
+      throw _privateConstructorUsedError;
+}

backend-dart/lib/domain/errors/error_code.dart

@@ -0,0 +1,15 @@
+enum ErrorCode {
+  networkError, // Fehler bei der Netzwerkkommunikation
+  validationError, // Eingabevalidierungsfehler
+  unexpectedError, // Unerwarteter Fehler
+  authenticationError, // Authentifizierungsfehler
+  permissionDenied, // Berechtigungsfehler
+  notFound, // Ressource nicht gefunden
+  exception, // Ausnahme
+  mappingError, // Fehler beim Zuordnen von Daten
+  databaseError, // Datenbankfehler
+  inputError, // Eingabefehler
+  outputError, // Ausgabefehler
+  internalError, // Interner Fehler
+  unknownError, // Unbekannter Fehler
+}

backend-dart/lib/domain/interface/database.dart

@@ -0,0 +1,7 @@
+import 'package:backend_dart/domain/data/user_data_source.dart';
+import 'package:backend_dart/domain/entities/user.dart';
+
+abstract class IDatabase {
+  UserDataSource<User> get users;
+  Future<void> close();
+}

backend-dart/lib/domain/interface/error.dart

@@ -0,0 +1,8 @@
+import 'package:backend_dart/domain/errors/error_code.dart';
+
+abstract class IError {
+  ErrorCode get code; // Fehlercode
+  String get message; // Fehlermeldung
+  StackTrace? get stackTrace; // Stacktrace
+  Map<String, String>? get details; // Zusätzliche Details
+}

backend-dart/lib/domain/interface/mapper.dart

@@ -0,0 +1,16 @@
+import 'package:backend_dart/domain/interface/error.dart';
+import 'package:fpdart/fpdart.dart';
+
+abstract class IMapper<U, V> {
+  /// Konvertiert von Typ U (Origin) zu Typ V (Target)
+  TaskEither<IError, V> to(U origin);
+
+  /// Konvertiert von Typ V (Target) zu Typ U (Origin)
+  TaskEither<IError, U> from(V target);
+
+  /// Konvertiert eine Liste von Typ U (Origin) zu einer Liste von Typ V (Target)
+  TaskEither<IError, List<V>> listTo(Iterable<U> origins);
+
+  /// Konvertiert eine Liste von Typ V (Target) zu einer Liste von Typ U (Origin)
+  TaskEither<IError, List<U>> listFrom(Iterable<V> targets);
+}

backend-dart/lib/domain/repositories/user_repository.dart

@@ -1,7 +0,0 @@
-import 'package:backend_dart/domain/entities/user.dart';
-
-abstract class UserRepository {
-  Future<void> create(User user);
-  Future<User?> findByEmail(String email);
-  Future<User?> findById(String id);
-}

backend-dart/lib/domain/repository/user_repository.dart

@@ -0,0 +1,17 @@
+import 'package:backend_dart/domain/entities/user.dart';
+import 'package:backend_dart/domain/interface/error.dart';
+import 'package:fpdart/fpdart.dart';
+
+abstract class UserRepository {
+  TaskEither<IError, User> create(User user);
+
+  TaskEither<IError, User> findByEmail(String email);
+
+  TaskEither<IError, User> findById(String id);
+
+  TaskEither<IError, User> update(User user);
+
+  TaskEither<IError, void> delete(String id);
+
+  TaskEither<IError, List<User>> findAll();
+}

backend-dart/lib/infrastructure/persistence/database.dart

@@ -1,13 +0,0 @@
-import 'package:backend_dart/infrastructure/persistence/db/client.dart';
-import 'package:backend_dart/infrastructure/persistence/prisma_user_repository.dart';
-
-class Database {
-  final prisma = PrismaClient();
-  late final PrismaUserRepository users;
-  Database() {
-    users = PrismaUserRepository(prisma);
-    print('Database initialized');
-  }
-
-
-}

backend-dart/lib/infrastructure/persistence/database_provider.dart

@@ -1,8 +1,8 @@
-import 'package:backend_dart/infrastructure/persistence/database.dart';
+import 'package:backend_dart/infrastructure/persistence/prisma_database.dart';
 import 'package:riverpod/riverpod.dart';
 
-final databaseProvider = Provider<Database>((ref) {
+final databaseProvider = Provider<PrismaDatabase>((ref) {
   // Hier die Datenbankverbindung initialisieren
-  final database = Database();
+  final database = PrismaDatabase();
   return database;
 });

backend-dart/lib/infrastructure/persistence/mapper/user_dbo_mapper.dart

@@ -0,0 +1,37 @@
+import 'package:backend_dart/domain/entities/user.dart';
+import 'package:backend_dart/domain/interface/error.dart';
+import 'package:backend_dart/domain/interface/mapper.dart';
+import 'package:backend_dart/infrastructure/persistence/db/model.dart';
+import 'package:fpdart/fpdart.dart';
+
+class UserDboMapper implements IMapper<User, UserDbo> {
+  @override
+  TaskEither<IError, User> from(UserDbo target) => TaskEither.of(User(
+        id: target.id!,
+        name: target.name!,
+        email: target.email!,
+        password: target.password,
+        createdAt: target.createdAt,
+        updatedAt: target.updatedAt,
+      ));
+
+  @override
+  TaskEither<IError, List<User>> listFrom(Iterable<UserDbo> targets) {
+    return TaskEither.traverseList(targets.toList(), from);
+  }
+
+  @override
+  TaskEither<IError, List<UserDbo>> listTo(Iterable<User> origins) {
+    return TaskEither.traverseList(origins.toList(), to);
+  }
+
+  @override
+  TaskEither<IError, UserDbo> to(User origin) => TaskEither.of(UserDbo(
+        id: origin.id,
+        name: origin.name,
+        email: origin.email,
+        password: origin.password,
+        createdAt: origin.createdAt,
+        updatedAt: origin.updatedAt,
+      ));
+}

backend-dart/lib/infrastructure/persistence/prisma_database.dart

@@ -0,0 +1,19 @@
+import 'package:backend_dart/domain/interface/database.dart';
+import 'package:backend_dart/infrastructure/persistence/db/client.dart';
+import 'package:backend_dart/infrastructure/persistence/prisma_user_data_source.dart';
+
+class PrismaDatabase implements IDatabase {
+  final prisma = PrismaClient();
+  late final PrismaUserDataSource _users;
+  PrismaDatabase() {
+    _users = PrismaUserDataSource(prisma);
+    print('Database initialized');
+  }
+
+  @override
+  get users => _users;
+  @override
+  Future<void> close() {
+    return Future.value();
+  }
+}

backend-dart/lib/infrastructure/persistence/prisma_user_data_source.dart

@@ -0,0 +1,162 @@
+import 'package:backend_dart/common/error_on_null.dart';
+import 'package:backend_dart/domain/data/user_data_source.dart';
+import 'package:backend_dart/domain/entities/user.dart';
+import 'package:backend_dart/domain/errors/app_error.dart';
+import 'package:backend_dart/domain/interface/error.dart';
+import 'package:backend_dart/infrastructure/persistence/db/model.dart';
+import 'package:backend_dart/infrastructure/persistence/db/prisma.dart';
+import 'package:backend_dart/infrastructure/persistence/mapper/user_dbo_mapper.dart';
+import 'package:fpdart/fpdart.dart';
+import 'package:orm/orm.dart';
+import 'package:uuid/uuid.dart';
+
+import 'db/client.dart';
+
+class PrismaUserDataSource implements UserDataSource<User> {
+  final PrismaClient prisma;
+  final UserDboMapper mapper = UserDboMapper();
+  PrismaUserDataSource(this.prisma);
+
+  @override
+  TaskEither<IError, User> create(User user) {
+    return TaskEither<IError, UserDbo>.tryCatch(
+      () async {
+        if (user.password == null) {
+          throw Exception('Password is required');
+        }
+        if (user.email == null) {
+          throw Exception('Email is required');
+        }
+        final createdUser = await prisma.userDbo.create(
+          data: PrismaUnion.$1(UserDboCreateInput(
+            id: user.id,
+            name: user.name!,
+            email: user.email!,
+            password: user.password!,
+          )),
+        );
+        return createdUser;
+      },
+      (error, _) => AppError.databaseError(
+        message: 'Failed to create user: ${error.toString()}',
+      ),
+    ).flatMap(mapper.from);
+  }
+
+  @override
+  TaskEither<IError, User> findByEmail(String email) {
+    return TaskEither<IError, UserDbo?>.tryCatch(
+      () async {
+        final user = await prisma.userDbo
+            .findUnique(where: UserDboWhereUniqueInput(email: email));
+        if (user == null) return null;
+        return user;
+      },
+      (error, _) => AppError.databaseError(
+        message: 'Failed to find user by email: ${error.toString()}',
+      ),
+    )
+        .flatMap(errorOnNull(AppError.notFound(
+          'User with email $email found',
+        )))
+        .flatMap(mapper.from);
+  }
+
+  @override
+  TaskEither<IError, User> findById(String id) {
+    return TaskEither<IError, UserDbo?>.tryCatch(
+      () async {
+        final user = await prisma.userDbo
+            .findUnique(where: UserDboWhereUniqueInput(id: id));
+        return user;
+      },
+      (error, _) => AppError.databaseError(
+        message: 'Failed to find user by ID: ${error.toString()}',
+      ),
+    )
+        .flatMap(errorOnNull(AppError.notFound(
+          "User with id $id not found",
+        )))
+        .flatMap(mapper.from);
+  }
+
+  @override
+  TaskEither<IError, User> update(User user) {
+    return mapper
+        .to(user)
+        .flatMap((userDbo) => TaskEither.tryCatch(() async {
+              // Führe das Update durch
+              if (userDbo.id == null) {
+                throw Exception('User ID is required');
+              }
+
+              final updatedUser = await prisma.userDbo.update(
+                data: PrismaUnion.$2(
+                  UserDboUncheckedUpdateInput(
+                    id: PrismaUnion.$1(userDbo.id!),
+                    name: userDbo.name != null
+                        ? PrismaUnion.$1(userDbo.name!)
+                        : null,
+                    email: userDbo.email != null
+                        ? PrismaUnion.$1(userDbo.email!)
+                        : null,
+                    password: userDbo.password != null
+                        ? PrismaUnion.$1(userDbo.password!)
+                        : null,
+                  ),
+                ),
+                where: UserDboWhereUniqueInput(id: userDbo.id),
+              );
+
+              return updatedUser;
+            },
+                (error, _) => AppError.databaseError(
+                      message: 'Failed to update user: ${error.toString()}',
+                    )))
+        .flatMap(errorOnNull(AppError.notFound(
+          'User not found',
+        )))
+        .flatMap(mapper.from);
+  }
+
+  @override
+  TaskEither<IError, void> delete(String id) {
+    return TaskEither.tryCatch(
+      () async {
+        await prisma.userDbo.delete(where: UserDboWhereUniqueInput(id: id));
+      },
+      (error, _) => AppError.databaseError(
+        message: 'Failed to delete user: ${error.toString()}',
+      ),
+    );
+  }
+
+  @override
+  TaskEither<IError, List<User>> findAll() {
+    return TaskEither<IError, Iterable<UserDbo>>.tryCatch(
+      () async => await prisma.userDbo.findMany(),
+      (error, _) => AppError.databaseError(
+        message: 'Failed to fetch all users: ${error.toString()}',
+      ),
+    ).flatMap(mapper.listFrom);
+  }
+
+  @override
+  TaskEither<IError, String> generateId() {
+    return TaskEither.tryCatch(
+      () async {
+        var uuid = Uuid();
+        do {
+          final id = uuid.v4();
+          final user = await prisma.userDbo.findUnique(
+            where: UserDboWhereUniqueInput(id: id),
+          );
+          if (user == null) return id;
+        } while (true);
+      },
+      (error, _) => AppError.databaseError(
+        message: 'Failed to generate ID: ${error.toString()}',
+      ),
+    );
+  }
+}

backend-dart/lib/infrastructure/persistence/prisma_user_repository.dart

@@ -1,57 +0,0 @@
-import 'package:backend_dart/domain/entities/user.dart';
-import 'package:backend_dart/domain/repositories/user_repository.dart';
-import 'package:backend_dart/infrastructure/persistence/db/prisma.dart';
-import 'package:orm/orm.dart';
-
-import 'db/client.dart';
-
-class PrismaUserRepository implements UserRepository {
-  final PrismaClient prisma;
-  PrismaUserRepository(this.prisma);
-
-  @override
-  Future<void> create(User user) async {
-    if (user.password == null) {
-      throw Exception('Password is required');
-    }
-    prisma.userDbo.create(
-        data: PrismaUnion.$1(UserDboCreateInput(
-      id: user.id,
-      name: user.name,
-      email: user.email,
-      password: user.password!,
-    )));
-  }
-
-  @override
-  Future<User?> findByEmail(String email) async {
-    final user = await prisma.userDbo
-        .findUnique(where: UserDboWhereUniqueInput(email: email));
-    if (user == null) {
-      return null;
-    }
-
-    return User(
-      id: user.id!,
-      name: user.name!,
-      email: user.email!,
-      password: user.password,
-    );
-  }
-
-  @override
-  Future<User?> findById(String id) async {
-    final user =
-        await prisma.userDbo.findUnique(where: UserDboWhereUniqueInput(id: id));
-    if (user == null) {
-      return null;
-    }
-
-    return User(
-      id: user.id!,
-      name: user.name!,
-      email: user.email!,
-      password: user.password,
-    );
-  }
-}

backend-dart/lib/interfaces/http/router.dart

@@ -1,4 +1,4 @@
-import 'package:backend_dart/application/user_service/user_service_provider.dart';
+import 'package:backend_dart/application/service/user_service_provider.dart';
 import 'package:riverpod/riverpod.dart';
 import 'package:shelf/shelf.dart';
 import 'package:shelf_router/shelf_router.dart';
@@ -15,10 +15,10 @@ Router getRouter(ProviderContainer container) {
     return Response.ok('Server is running');
   });
 
-  // UserService instanzieren
+  // Services
   final userService = container.read(userServiceProvider);
 
-  // UserService-Router an Haupt-Router binden
+  // UserService-Router
   router.mount('/users/', userService.router.call);
 
   return router;

backend-dart/pubspec.lock

@@ -799,7 +799,7 @@ packages:
     source: hosted
     version: "0.3.0"
   uuid:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: uuid
       sha256: a5be9ef6618a7ac1e964353ef476418026db906c4facdedaa299b7a2e71690ff

backend-dart/pubspec.yaml

@@ -20,6 +20,7 @@ dependencies:
   riverpod_annotation: ^2.6.1
   json_annotation: ^4.9.0
   freezed_annotation: ^2.4.4
+  uuid: ^4.5.1
   
 dev_dependencies:
   lints: ^3.0.0