app.js

const { log } = require('console');
const express = require('express');
const path=require('path');
const app = express();
const PORT = process.env.port || 3000;
const server=app.listen(PORT, () => {
    console.log(`Server is running on port ${PORT}.`);
}
)
const io=require('socket.io')(server);

app.use(express.static(path.join(__dirname, 'public')));

let socketsConnected=new Set();

io.on('connection', onConnected);
 

function onConnected(socket){
    socketsConnected.add(socket.id);
    io.emit("clients-total", socketsConnected.size);
    socket.on('disconnect', () => {
    console.log("Socket disconnected: " + socket.id);
    socketsConnected.delete(socket.id);
    io.emit("clients-total", socketsConnected.size);
    })

    socket.on('message', (data) => {
        // console.log(data);
        socket.broadcast.emit('chat-message', data);
    })

    socket.on('feedback', (data) => {
        socket.broadcast.emit('feedback', data);
    })
}