backend

const http = require('http');
const express = require('express');
const socketIO = require('socket.io');
const bodyParser = require('body-parser');
const multer = require('multer');
const consolidate = require('consolidate');
const session = require('express-session');

const app = express();
const server = http.Server(app);
const io = socketIO(server);
app.use(session({
    secret: 'zazagelovidzudzua', resave: false,
    saveUninitialized: true
}))
app.engine('html', consolidate.mustache);
app.set('view engine', 'html');
app.set('views', __dirname + '/views');

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.use(multer().array());
app.use(express.static('public'));

const mongoose = require('mongoose');
const connectionUri = 'mongodb://localhost/my_database';
mongoose.Promise = global.Promise;

mongoose
    .connect(connectionUri, { useNewUrlParser: true })
    .then(() => {
        console.log('Connection to database established');
    })
    .catch(error => {
        console.error('MongoDB connection error:', error.message);
        process.exit(-1);
    });


const Schema = mongoose.Schema;
const UserSchema = new Schema({

    username: String,
    password: String,
    email: String,

});



const User = mongoose.model('User', UserSchema);



app.get('/', (req, res) => {
    res.render('mainpage');
});

app.get('/reg', (req, res) => {
    res.render('reg');
});



app.post(
    '/reeg',
    async (req, res) => {
        try {
            const username = req.body.username
            const password = req.body.password
            const email = req.body.email

            const user = await User.create({ username, password, email });

            console.log('Created user:', user)

            res.sendFile(__dirname + '/views/mainpage.html')

        }
        catch (error) {
            res.status(500).send(error.message);
        }
    });


app.post('/login', async (req, res) => {
    try {
        const {username, password} = req.body;
        const user = await User.findOne({username}).lean();


        if (!user) {
                  return res.status(404).send({
                    message: 'user is not registered'
                  });
                }


        if (user.password !== password) {
                  return res.status(403).send({
                    message: 'user password invalid'
                  });
                }
        req.session.user = user;

        const redirectTo = '/dash';

        if (
          req.is('application/json') // request content type is json
          || // or
          req.xhr // is ajax
        ) {
          // respond with json response
          return res.status(200).status({redirectTo});
        }

        // not ajax request
        // then respond redirect header
        res.redirect(redirectTo);
    }
    catch (error) {
        res.status(500).send({
          message: error.message
        });
    }
});
app.get('/dash',
    async (req, res) => {
     try{
        if (!req.session.user) {
                res.status(401).send('login first please!')
        }

        res.status(200)

        res.send('Hi '  + req.session.user.username)
      }catch(error){
        console.log(error.message)
        return res.status(500)
      }
    })


server.listen('8080');