index.js

const express = require('express');
const cors = require('cors');
const morgan = require('morgan');
const helmet = require('helmet');
const yup = require('yup');
const monk = require('monk');

const { nanoid } = require('nanoid');

require('dotenv').config();

const db = monk(process.env.MONGO_URI);
const urls = db.get('urls');
urls.createIndex({'slug' : 1}, {unique: true});

const app = express();

app.use(helmet());
app.use(morgan('tiny'));
app.use(cors());
app.use(express.json());
app.use(express.static('./public'));

// app.get('/url/:id', (req, res) => {
//     //TODO: get a short url by id
// });

app.get('/:id', async (req, res) => {
    const {id: slug} = req.params;
    try{
        const url = await urls.findOne({slug});
        if(url){
            res.redirect(url.url);
        }
        res.redirect(`/?error=${slug} not found`);
    }catch (error) {
        res.redirect(`/?error=Link not found`);
    }
});

const schema = yup.object().shape({
    slug: yup.string().trim().matches(/[\w\-]/i),
    url: yup.string().trim().url().required(),

});

app.post('/url', async (req,res, next) => {
    let {slug, url} = req.body;
    try {
        await schema.validate({
            slug,
            url,
        });
        if(!slug){
            slug = nanoid(5);
        }else{
            const existing = await urls.findOne({ slug });
            if(existing){
                throw new Error('Slug in use. 🍔');
            }
        }
        slug = slug.toLowerCase();
        const newUrl = {
            url,
            slug,
        };
        const created = await urls.insert(newUrl);
        res.json(created);
    } catch (error){
        next(error);
    }
});

app.use((error, req, res, next) => {
    if(error.status){
        res.status(error.status);
    }else{
        res.status(500);
    }
    res.json({
        message: error.message,
        stack: process.env.NODE_ENV === 'production' ? '🥞': error.stack,
    })
    
})



const port = process.env.PORT || 5050;
app.listen(port, () => {
   console.log(`Listning at http://localhost:${port}`);
});