index.js

const express = require('express')
const session = require('express-session');
const app = express()
const db = require('mongoose')
const UrlDetail = require('./models/url')
require('dotenv').config();
const {
	nanoid
} = require('nanoid');
const bodyParser = require('body-parser');

const PORT = process.env.PORT || 3000

app.use(express.urlencoded({
	extended: false
}))
app.set('view engine', 'ejs')

const captcha = require('svg-captcha-express').create({
	cookie: 'captcha',
	size: 5,
	noise: 3,
	width: 200,
	height: 50,
	background: '#fafafa',
	charPreset: 'ABCDEFGHJKLMNPQRSTUVWXYZ23456789',
});

app.use(
	session({
		secret: process.env.SECRET,
		resave: false,
		saveUninitialized: true
	})
);

app.use(bodyParser.urlencoded({
	extended: false
}));

db.connect(process.env.MONGODB_URI, {
	useNewUrlParser: true,
	useUnifiedTopology: true
})

app.get('/captcha.jpg', captcha.image());

app.get('/', async (req, res) => {
	const allUrls = await UrlDetail.find({
		owner: req.headers['x-forwarded-for'] || req.socket.remoteAddress
	})
	res.render('index', {
		captcha: '/captcha.jpg',
		urlsData: allUrls,
		siteUrl: req.protocol + '://' + req.get('host') + req.originalUrl
	})
})

app.post('/short_url', async (req, res) => {
	if (!captcha.check(req, req.body.captcha))
		return res.send('Invalid captcha')
	const originalUrl = req.body.originalUrl
	const record = new UrlDetail({
		fullUrl: originalUrl,
		owner: req.headers['x-forwarded-for'] || req.socket.remoteAddress,
		shortUrl: nanoid(6)
	})
	await record.save()
	res.redirect('/')
})

app.get('/:shortID', async (req, res) => {
	const shortID = req.params.shortID
	const urlDetails = await UrlDetail.findOne({
		shortUrl: shortID
	})
	if (!urlDetails) return res.status(404).send('No short url found')
	urlDetails.hits += 1
	await urlDetails.save()
	res.redirect(urlDetails.fullUrl)
})

db.connection.on('open', async () => {
	app.listen(PORT, () => {
		console.log('Listening on PORT: ' + PORT)
	})
})