server.js

const express = require('express');
const path = require('path');
const http = require('http');
const socketio = require('socket.io');
const formatMessage = require('./utils/messages');
const {userJoin, getCurrentUser, userLeave, getRoomUsers} = require('./utils/users');

const app = express();
const server = http.createServer(app);
const io = socketio(server);
const botName = 'Chat Bot';

//Setting the static folder
app.use(express.static(path.join(__dirname, 'public')));

//Notify when a user connects
io.on('connection', socket => {
    // Listen for when a user joins a room
    socket.on('joinRoom', ({ username, room }) => {
        const user = userJoin(socket.id, username, room);

        socket.join(user.room);

        //Welcome a user to the Chat room
        socket.emit('message', formatMessage(botName, 'Welcome to ChatCord!'));

        //Broadcast when a user connects
        socket.broadcast.to(user.room).emit('message', formatMessage(botName, `${user.username} has joined.`));

        //send users and room info as an event payload to the frontend
        io.to(user.room).emit('roomUsers', {
            room: user.room,
            users: getRoomUsers(user.room)
        });
    });

    //Listen for when a user sends a message
    socket.on('chatMessage', (msg) => {
        const user = getCurrentUser(socket.id);
        //Emit the message to everybody
        io.to(user.room).emit('message', formatMessage(user.username, msg));
    });

    //Runs when a user disconnects
    socket.on('disconnect', () => {
        const user = userLeave(socket.id);
        if (user) {
            io.to(user.room).emit('message', formatMessage(botName, `${user.username} has left the chat.`));
            //send users and room info
            io.to(user.room).emit('roomUsers', {
                room: user.room,
                users: getRoomUsers(user.room)
            });
        }
    });
})

const PORT = process.env.PORT || 5000;

server.listen(PORT, () => console.log(`Server is running on port ${PORT}`));