Refactor chat screen using clean architecture

.gitignore

@@ -72,6 +72,6 @@ ios/fastlane/*p8
 ios/fastlane/.env
 ios/fastlane/report.xml
 
-lib/home/Chat/chat_config.dart
+lib/data/core/chat_config.dart
 
 coverage

lib/data/core/api_constants.dart

@@ -0,0 +1,7 @@
+import 'package:swiftcomp/data/core/chat_config.dart';
+
+class ApiConstants {
+  static const String baseUrl = 'https://api.openai.com/v1';
+  static const String chatEndpoint = '$baseUrl/chat/completions';
+  static String apiKey = ChatConfig.apiKey;
+}

lib/data/core/network_exceptions.dart

@@ -0,0 +1,5 @@
+class NetworkException implements Exception {
+  final String message;
+
+  NetworkException(this.message);
+}

lib/data/data_sources/chat_remote_data_source.dart

@@ -0,0 +1,66 @@
+import 'dart:convert';
+import 'package:http/http.dart' as http;
+import '../../domain/entities/chat_session.dart';
+import '../../domain/entities/message.dart';
+import '../core/api_constants.dart';
+import '../core/network_exceptions.dart';
+
+abstract class ChatRemoteDataSource {
+  Stream<String> sendMessages(List<Message> messages);
+}
+
+class ChatRemoteDataSourceImpl implements ChatRemoteDataSource {
+  final http.Client client;
+
+  ChatRemoteDataSourceImpl({required this.client});
+
+  @override
+  Stream<String> sendMessages(List<Message> messages) async* {
+    final request = http.Request('POST', Uri.parse(ApiConstants.chatEndpoint))
+      ..headers.addAll({
+        'Content-Type': 'application/json',
+        'Authorization': 'Bearer ${ApiConstants.apiKey}',
+      })
+      ..body = jsonEncode({
+        "model": "gpt-4o",
+        "stream": true,
+        'messages': messages,
+      });
+
+    final response = await client.send(request);
+
+    if (response.statusCode == 200) {
+      final utf8DecodedStream = response.stream.transform(utf8.decoder);
+      String buffer = '';
+
+      await for (var chunk in utf8DecodedStream) {
+        buffer += chunk;
+        List<String> lines = buffer.split('\n');
+        buffer = lines.removeLast();
+
+        for (var line in lines) {
+          if (line.startsWith('data:')) {
+            var jsonString = line.replaceFirst('data: ', '').trim();
+
+            if (jsonString == '[DONE]') {
+              return;
+            }
+
+            try {
+              final data = jsonDecode(jsonString);
+              final content = data['choices'][0]['delta']['content'] ?? '';
+              if (content.isNotEmpty) {
+                yield content;
+              }
+            } catch (_) {
+              // Handle JSON parsing errors
+              continue;
+            }
+          }
+        }
+      }
+    } else {
+      throw NetworkException('Failed to send message: ${response.statusCode}');
+    }
+  }
+}

lib/data/repositories/chat_repository_impl.dart

@@ -0,0 +1,15 @@
+import '../../domain/entities/chat_session.dart';
+import '../../domain/entities/message.dart';
+import '../../domain/repositories_abstract/chat_repository.dart';
+import '../data_sources/chat_remote_data_source.dart';
+
+class ChatRepositoryImp implements ChatRepository {
+  final ChatRemoteDataSource remoteDataSource;
+
+  ChatRepositoryImp({required this.remoteDataSource});
+
+  @override
+  Stream<String> sendMessages(List<Message> messages) {
+    return remoteDataSource.sendMessages(messages);
+  }
+}

lib/data/repositories/chat_session_repository_imp.dart

@@ -0,0 +1,30 @@
+import '../../domain/entities/chat_session.dart';
+import '../../domain/repositories_abstract/chat_session_repository.dart';
+
+class ChatSessionRepositoryImpl implements ChatSessionRepository {
+  @override
+  Future<List<ChatSession>> getAllSessions() async {
+    // Fetch sessions from data source (e.g., local storage, API)
+    return [];
+  }
+
+  @override
+  Future<void> createSession(ChatSession session) async {
+    // Create session to a data source
+  }
+
+  @override
+  Future<void> saveSession(ChatSession session) async {
+    // Save session to a data source
+  }
+
+  @override
+  Future<void> deleteSession(String id) async {
+    // Delete session from data source
+  }
+
+  @override
+  Future<ChatSession?> selectSession(String id) async {
+    return null;
+  }
+}

lib/domain/entities/chat_session.dart

@@ -0,0 +1,33 @@
+import 'message.dart';
+
+class ChatSession {
+  final String id;
+  final String title;
+  List<Message> messages;
+
+  // Constructor
+  ChatSession({
+    required this.id,
+    required this.title,
+    List<Message>? messages, // Optional parameter for messages
+  }) : messages = messages ?? []; // Initialize messages as an empty list if null
+
+  factory ChatSession.fromJson(Map<String, dynamic> json) {
+    var messagesJson = json['messages'] as List;
+    List<Message> messages = messagesJson.map((msg) => Message.fromJson(msg)).toList();
+
+    return ChatSession(
+      id: json['id'],
+      title: json['title'],
+      messages: messages,
+    );
+  }
+
+  Map<String, dynamic> toJson() {
+    return {
+      'id': id,
+      'title': title,
+      'messages': messages.map((msg) => (msg as Message).toJson()).toList(),
+    };
+  }
+}

lib/domain/entities/message.dart

@@ -0,0 +1,22 @@
+class Message {
+  final String role;
+  String content;
+
+  Message({required this.role, required this.content});
+
+  // Factory constructor for creating a new Message instance from JSON
+  factory Message.fromJson(Map<String, dynamic> json) {
+    return Message(
+      role: json['role'],
+      content: json['content'],
+    );
+  }
+
+  // Method for converting a Message instance to JSON format
+  Map<String, dynamic> toJson() {
+    return {
+      'role': role,
+      'content': content,
+    };
+  }
+}

lib/domain/repositories_abstract/chat_repository.dart

@@ -0,0 +1,5 @@
+import '../entities/message.dart';
+
+abstract class ChatRepository {
+  Stream<String> sendMessages(List<Message> messages);
+}

lib/domain/repositories_abstract/chat_session_repository.dart

@@ -0,0 +1,9 @@
+import '../entities/chat_session.dart';
+
+abstract class ChatSessionRepository {
+  Future<List<ChatSession>> getAllSessions();  // Fetch sessions from a data source
+  Future<void> createSession(ChatSession session);
+  Future<void> saveSession(ChatSession session);
+  Future<void> deleteSession(String id);
+  Future<ChatSession?> selectSession(String id);
+}

lib/domain/usecases/chat_session_usecase.dart

@@ -0,0 +1,53 @@
+import '../entities/chat_session.dart';
+import '../entities/message.dart';
+import '../repositories_abstract/chat_session_repository.dart';
+
+class ChatSessionUseCase {
+  final ChatSessionRepository repository;
+
+  ChatSessionUseCase(this.repository);
+
+  Future<List<ChatSession>> getAllSessions() async {
+    return repository.getAllSessions();
+  }
+
+  Future<void> saveSession(ChatSession session) async {
+    // You can add business rules here (e.g., session validation)
+    repository.saveSession(session);
+  }
+
+  Future<void> deleteSession(String sessionId) async {
+    repository.deleteSession(sessionId);
+  }
+
+  @override
+  Future<void> createSession(ChatSession session) async {
+    repository.createSession(session);
+  }
+
+  void addMessageToSession(ChatSession session, Message message) {
+    session.messages.add(message);
+    saveSession(session);
+  }
+
+  // Check if the last message in the session is from the assistant
+  bool isLastMessageAssistInSession(ChatSession session) {
+    final messages = session.messages;
+    if (messages != null && messages.isNotEmpty) {
+      return messages.last.role == 'assistant';
+    }
+    return false;
+  }
+
+  // Add a new method to update the last assistant message
+  void updateLastAssistantMessage(ChatSession session, String token) {
+    // Find the last message that is from the assistant
+    for (var i = session.messages.length - 1; i >= 0; i--) {
+      if (session.messages[i].role == 'assistant') {
+        final previousContent = session.messages[i].content;
+        session.messages[i] = Message(role: 'assistant', content: previousContent + token);
+        break;
+      }
+    }
+  }
+}

lib/domain/usecases/chat_usecase.dart

@@ -0,0 +1,12 @@
+import '../entities/message.dart';
+import '../repositories_abstract/chat_repository.dart';
+
+class ChatUseCase {
+  final ChatRepository repository;
+
+  ChatUseCase(this.repository);
+
+  Stream<String> sendMessages(List<Message> messages) {
+    return repository.sendMessages(messages);
+  }
+}