构建现代化 IM系统

@WebSocketGateway({ cors: { origin: '*' } })
export class ChatGateway implements 
  OnGatewayInit, OnGatewayConnection, OnGatewayDisconnect {
  
  @WebSocketServer() server: Server;
  
  @SubscribeMessage('message')
  async handleMessage(
    @MessageBody() payload: CreateMessageDto,
    @ConnectedSocket() client: Socket
  ) {
    const message = await this.chatService.create(payload);
    this.server.to(payload.room).emit('message', message);
  }
  
  @SubscribeMessage('joinRoom')
  handleJoinRoom(
    @MessageBody() payload: { room: string },
    @ConnectedSocket() client: Socket
  ) {
    client.join(payload.room);
    client.emit('joined', { room: payload.room });
  }
}

model User {
  id        String   @id @default(cuid())
  email     String   @unique
  username  String   @unique
  password  String
  status    UserStatus @default(ONLINE)
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt
  
  sentMessages     Message[] @relation("SentMessages")
  receivedMessages Message[] @relation("ReceivedMessages")
  groupMembers     GroupMember[]
  
  @@map("users")
}

model Message {
  id        String   @id @default(cuid())
  content   String
  type      MessageType @default(TEXT)
  room      String
  senderId  String
  receiverId String?
  createdAt DateTime @default(now())
  
  sender    User @relation("SentMessages", fields: [senderId], references: [id])
  receiver  User? @relation("ReceivedMessages", fields: [receiverId], references: [id])
  
  @@map("messages")
}