service.socket.io.ts

socket.io.ts

import { Server, type Socket } from "socket.io";

class SocketService {
  private static instance: SocketService;
  private _io: Server;
  private _sockets: Record<string, Socket> = {}; // Store sockets by user ID

  private constructor() {
    console.log("Initializing Socket Service...");
    this._io = new Server({
      cors: {
        allowedHeaders: ["*"],
        origin: "*",
      },
    });
  }

  // Singleton pattern to ensure only one instance exists
  public static getInstance(): SocketService {
    if (!SocketService.instance) {
      SocketService.instance = new SocketService();
    }
    return SocketService.instance;
  }

  // Initialize Socket.IO event listeners
  public initListener(): void {
    this._io.on("connect", (socket: Socket) => {
      console.log(`Socket connected: ${socket.id}`);

      // Handle disconnect event
      socket.on("disconnect", (disconnectReason: string) => {
        console.info("Disconnect reason:", disconnectReason);
        // Clean up disconnected sockets
        for (const [userId, userSocket] of Object.entries(this._sockets)) {
          if (userSocket.id === socket.id) {
            delete this._sockets[userId];
            console.info(`User ${userId} disconnected`);
            break;
          }
        }
      });
    });
  }

  // Getter for the Socket.IO server instance
  public get io(): Server {
    return this._io;
  }

  // Emit an event to all connected clients
  public emit(event: string, data: string): void {
    // data : json.stringify
    this._io.emit(event, data);
  }
}

export default SocketService.getInstance();