index.js

import { getuid } from "process";
import { Server } from "socket.io";
// import { createServer } from "http";

// const httpServer = createServer();

const io = new Server(8900, {
  cors: {
    origin: `http://localhost:3000`,
  },
});

let users = [];

const addUser = (userId, socketId) => {
  !users.some((user) => user.userId === userId) &&
    users.push({ userId, socketId });
};

const removeUser = (socketId) => {
  users = users.filter((user) => user.socketId !== socketId);
};

const getUser = (userId) => {
  return users.find((user) => user.userId === userId);
};

io.on("connection", (socket) => {
  //when connect
  console.log(`user connected`);
  //take userId and socketId from user
  socket.on("addUser", (userId) => {
    addUser(userId, socket.id);
    io.emit("getUsers", users);
  });

  //send and get message
  socket.on("sendMessage", ({ senderId, receiverId, text }) => {
    const user = getUser(receiverId);
    io.to(user.socketId).emit("getMessage", {
      senderId,
      text,
    });
  });

  //when disconnect
  socket.on("disconnect", () => {
    console.log(`a user disconnected`);
    removeUser(socket.id);
    io.emit("getUsers", users);
  });
});

// httpServer.listen(8900);

// const io = require("socket.io")(8900, {
//   cors: {
//     origin: "http://localhost:3000",
//   },
// });

// io.on("connection", (socket) => {
//   console.log(`user connected`);
// });