app.js

const express = require('express')
const passport = require('passport')
const session = require('express-session')
const RedisStore = require('connect-redis')(session)
const app = express()
const mysql = require('mysql')
const fs = require('fs')
let config = require('./config.js')
let connection = mysql.createConnection(config)

//Sets the template engine ejs
app.set('view engine', 'ejs')

//session middleware
app.use(session({
    store: new RedisStore({
      url: config.redisStore.url
    }),
    secret: config.redisStore.secret,
    resave: false,
    saveUninitialized: false
  }))
  app.use(passport.initialize())
  app.use(passport.session())

//Middleware
app.use(express.static('public'))

//Simple request time logger
app.use(function(req, res, next) {
    console.log(`Middleware`)
    console.log(`req: ${req}`)
    console.log(`res: ${res}`)
    console.log(`Url: ${req.url}`);

    
    //This function call is very important. It tells that more processing is
    //required for the current request and is in the next middleware
    next();
 });

//Routes
app.get('/', (req, res) =>{
    console.log(`get "/", req: ${req}, res: ${res}`)
    res.render('index')

} )

let PORT = 1337
server = app.listen(PORT)

console.log(`Listen on port ${PORT}`)

const io = require("socket.io")(server)
//const hist = []

let obj = {
    hist: []
};

//Listen for a new connection
io.on('connection', (socket) => {
        console.log('io event: connection')

        console.log('New user connected. Socket id: ', socket.id)


        socket.username = "Anonymous"
        send_hist(socket)
        

    socket.on('change_username', (data) => {
        console.log('io event: change_username')
        socket.username = data.username
    })


    //listen on new_message
    socket.on('new_message', (data) => {
        console.log('io event: new_message')

        //broadcast the new message
        io.sockets.emit('new_message', {message : data.message, username : socket.username})
        var msg = data


           //MySQL data upload
           let config = require('./config.js');
           let connection = mysql.createConnection(config);
           // insert statment
           let stmt = `INSERT INTO logs(username,message)
                       VALUES(?,?)`;  
           let inpt = [socket.username, msg.message];
           
           // execute the insert statment
           connection.query(stmt, inpt, (err, results, fields) => {
               if (err) {
                   return console.error(err.message);
    }
           // get inserted id
           console.log('Message Id:' + results.insertId);
  });
   
           connection.end();
    })

    //listen on typing
    socket.on('typing', (data) => {
        console.log('io event: typing')

    	socket.broadcast.emit('typing', {username : socket.username})
    })

})

 function send_hist (socket){
    console.log('send_hist()')

    //Sending history to a single socket from MySQL
    let config = require('./config.js');
    let connection = mysql.createConnection(config);
 
    let sql = `SELECT username, message FROM logs`;

    connection.query(sql, (error, results, fields) => {
      if (error) {
          return console.error(error.message);
  }

    //console.log(results);
    results.forEach(element => {
        io.to(socket.id).emit('new_message', element);



        
    });

});
 
connection.end();
     
}