server.js

const path = require('path');
const http = require('http');
const express = require('express');
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);

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

const botName = 'Chat Bot';

//Run when client connects
io.on('connection', socket=>{
    socket.on('joinRoom', ({username, room}) =>{
       const user = userJoin(socket.id, username, room);

       socket.join(user.room);
       
       //Welcome current user
       socket.emit('message', formatMessage(botName,'Welcome to the chat'));  //single client

       //Broadcast when a user connects
       socket.broadcast.to(user.room).emit('message', formatMessage(botName, `${user.username} has joined the chat`));   //this will emit to everyone except the user
    
      //Send users and room info
      io.to(user.room).emit('roomUsers', {
          room: user.room,
          users: getRoomUsers(user.room)
      });
    });

    //Listen for chatMessage
    socket.on('chatMessage', msg =>{
        const user = getCurrentUser(socket.id);

        io.to(user.room).emit('message',formatMessage(user.username, msg));
    });
 
    //Runs when client 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`));     //all the clients
       
       //Send users and room info
        io.to(user.room).emit('roomUsers', {
        room: user.room,
        users: getRoomUsers(user.room)
       });
      }
    });
});

const PORT = 3000 || process.env.PORT;

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