App.js

var port = 5000

let nowerr;
let nowerr1;
let nowerr2;
let nowerr3;
require("dotenv").load()
var express = require('express');
var http = require("http");
var expressSession = require('express-session');
var bodyParser = require('body-parser');
var app = express();
var server = http.createServer(app);
var jsonParser = bodyParser.json()
var urlencodedParser = bodyParser.urlencoded({extended: false})
var commands = { };
let user = {}
var admin = require('firebase-admin');
admin.initializeApp({
    credential: admin.credential.cert({
        private_key: process.env.FIREBASE_PRIVATE_KEY,
        client_email: process.env.FIREBASE_CLIENT_EMAIL,
    }),
    databaseURL: process.env.DBURL
});


var db = admin.database();

server.listen(process.env.PORT || port);
app.set('port', (process.env.PORT || port));
app.use(expressSession({secret: 'max'}))
app.set('view engine', 'ejs')
app.get('/signup', function(req, res) {
    res.render('signup',{commands:commands, err1: nowerr, err2: nowerr1, err3: nowerr2, err4: nowerr3});
});
app.get('/login', function(req, res) {
    res.render('login',{commands:commands, err1: nowerr, err2: nowerr1, err3: nowerr2, err4: nowerr3});
});
app.get('/profile', function(req, res) {
    var fuser = admin.auth().currentUser;
var name, email

if (fuser != null) {
  name = fuser.displayName;
  email = fuser.email;
  res.render('profile',{user: user, name: name, email: email});//x
} else {
    res.redirect("/login")
}

});

const mysql = require("mysql");
var con = mysql.createConnection({
    host: process.env.HOST,
    user: "root",
    password: process.env.PASS,
    database: process.env.DB
})

app.post('/new/login', urlencodedParser, function(req, res) {
    var email = req.body.email,
        name = req.body.name
        pass = req.body.pass;
if(!email) return;
if(!pass) return;
if(!name) return;
if(pass.length < 2) {
    nowerr = "can't be lower than 2 letters"
    setTimeout(() => { nowerr = "" }, 1000)
}
if(name.length < 2) {
nowerr1 = "can't be lower than 2 letters"
    setTimeout(() => { nowerr1 = "" }, 1000)
}
if(!email.includes("@") || !email.includes(".")) {
    nowerr2 = "enter a vaild e-mail address"
        setTimeout(() => { nowerr2 = "" }, 1000)
}
else {
    admin.auth().createUser({
        displayName: req.body.username,
       email: req.body.email,
       password: req.body.password
  })
.then(function(userRecord) {
  console.log("Successfully created new user:", userRecord.uid);
  userRecord.rememberme = req.body.rememberme
    res.send(userRecord);
})
.catch(function(error) {
     return res.status(400).send(error);
  console.log("Error creating new user:", error);
});
user.name = name
user.email = email
}

    res.redirect('/profile');
} );
app.post('/old/login', urlencodedParser, function(req, res) {
    var email = req.body.email,
        pass = req.body.pass;
if(!email) return;
if(!pass) return;
if(pass.length < 2) {
    nowerr = "can't be lower than 2 letters"
    setTimeout(() => { nowerr = "" }, 1000)
}

if(!email.includes("@") || !email.includes(".")) {
    nowerr2 = "enter a vaild e-mail address"
        setTimeout(() => { nowerr2 = "" }, 1000)
}
else {
con.query(`SELECT * FROM accs WHERE email = '${email}' AND password = '${pass}'`, (err, rows) => {
    if(err) throw err;
if(!rows[0] || rows.length < 0) {
    nowerr1 = "User or password is not correct !"
    setTimeout(() => { nowerr1 = "" }, 1000)

}
else {

if(rows[0].email === email && rows[0].password === pass) {
user.name = rows[0].username
user.email = email
    res.redirect('/profile');
} else {
    nowerr1 = "User or password is not correct !"
    setTimeout(() => { nowerr1 = "" }, 1000)

}
}
})
}
} );

app.on("error", () => console.error)
server.on("error", () => console.error)