server.js

const express = require('express')
const mongoose = require('mongoose')
const ShortUrl = require('./models/shortUrl')
const app = express()


const connectDB = async () => {
            try {
                        mongoose.connect(process.env.MONG_URI, {
                                    useNewUrlParser: true, useUnifiedTopology: true
                        }, console.log('MongoDB Connected...'))
            } catch (error) {
                        console.log(error);
                        process.exit(1);
            }
}

connectDB();

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

app.get('/', async (req, res) => {
            const shortUrls = await ShortUrl.find().sort({ clicks: -1 })
            res.render('index', { shortUrls: shortUrls })
})

app.post('/shortUrls', async (req, res) => {
            await ShortUrl.create({ full: req.body.fullUrl })

            res.redirect('/')
})

app.get('/:shortUrl', async (req, res) => {
            const shortUrl = await ShortUrl.findOne({ short: req.params.shortUrl })
            if (shortUrl == null) return res.sendStatus(404)

            shortUrl.clicks++
            shortUrl.save()

            res.redirect(shortUrl.full)
})

app.listen(process.env.PORT || 5000);