Hightube/frontend/lib/services/chat_service.dart

import 'dart:async';
import 'dart:convert';
import 'package:web_socket_channel/web_socket_channel.dart';

class ChatMessage {
  final String type;
  final String username;
  final String content;
  final String roomId;
  final bool isHistory;

  ChatMessage({
    required this.type,
    required this.username,
    required this.content,
    required this.roomId,
    this.isHistory = false,
  });

  factory ChatMessage.fromJson(Map<String, dynamic> json) {
    return ChatMessage(
      type: json['type'] ?? 'chat',
      username: json['username'] ?? 'Anonymous',
      content: json['content'] ?? '',
      roomId: json['room_id'] ?? '',
      isHistory: json['is_history'] ?? false,
    );
  }

  Map<String, dynamic> toJson() => {
    'type': type,
    'username': username,
    'content': content,
    'room_id': roomId,
    'is_history': isHistory,
  };
}

class ChatService {
  WebSocketChannel? _channel;
  final StreamController<ChatMessage> _messageController = StreamController<ChatMessage>.broadcast();

  Stream<ChatMessage> get messages => _messageController.stream;

  void connect(String baseUrl, String roomId, String username) {
    final wsUri = Uri.parse(baseUrl).replace(scheme: 'ws', path: '/api/ws/room/$roomId', queryParameters: {'username': username});
    _channel = WebSocketChannel.connect(wsUri);

    _channel!.stream.listen((data) {
      final json = jsonDecode(data);
      _messageController.add(ChatMessage.fromJson(json));
    }, onError: (err) {
      print("[WS ERROR] $err");
    }, onDone: () {
      print("[WS DONE] Connection closed");
    });
  }

  void sendMessage(String content, String username, String roomId, {String type = 'chat'}) {
    if (_channel != null) {
      final msg = ChatMessage(type: type, username: username, content: content, roomId: roomId);
      _channel!.sink.add(jsonEncode(msg.toJson()));
    }
  }

  void dispose() {
    _channel?.sink.close();
    _messageController.close();
  }
}