const express = require("express");

const Socket = require("socket.io");

const PORT = 5000;

const app = express();

const server = require("http").createServer(app);

const io = Socket(server, {

cors: {

origin: "*",

methods: ["GET", "POST"],

},

});

const users = [];

io.on("connection", socket => {

socket.on("adduser", username => {

socket.user = username;

users.push(username);

io.sockets.emit("users", users);

io.to(socket.id).emit("private", {

id: socket.id,

name: socket.user,

msg: "secret message",

});

});

socket.on("message", message => {

io.sockets.emit("message", {

message,

user: socket.user,

id: socket.id,

});

});

socket.on("disconnect", () => {

console.log(`user ${socket.user} is disconnected`);

if (socket.user) {

users.splice(users.indexOf(socket.user), 1);

io.sockets.emit("user", users);

console.log("remaining users:", users);

}

});

});

server.listen(PORT, () => {

console.log("listening on PORT: ", PORT);

});