index.js

// Http module 
const http = require('http')
const fs = require('fs')
const path = require('path')

const app = http.createServer((req, res) => {

    res.writeHead(200, {
        'Content-Type': 'text/html'
    })


    // if(req.url === '/') {
    //     fs.readFile(path.join(__dirname, 'public', 'index.html'), (err, content) => {
    //         if(err) {
    //             throw err
    //         }
    //         res.end(content)
    //     })
    // } else if(req.url === '/about') {
    //     fs.readFile(path.join(__dirname, 'public', 'about.html'), (err, content) => {
    //         if(err) {
    //             throw err
    //         }
    //         res.end(content)
    //     })
    // }


    let filePath = path.join(__dirname, 'public', req.url === '/' ? 'index.html' : req.url)

    let conteType = 'text/html'

    let ext = path.extname(filePath)
    if (!ext) {
        filePath += '.html'
    }

    switch (ext) {
        case '.css':
            contentType = 'text/css'
            break
        case '.js':
            contentType = 'text/javascript'
            break
        default:
            contentType = 'text/html'
    }

    fs.readFile(filePath, (err, content) => {
        if (err) {
            fs.readFile(path.join(__dirname, 'public', 'error.html'), (err, data) => {
                if (err) {
                    res.writeHead(500)
                    res.end('Error!!!')
                } else {
                    res.writeHead(404, {
                        'Content-Type': contentType
                    })
                    res.end(data)
                }
            })
        } else {
            res.writeHead(200, {
                'Content-Type': contentType
            })
            res.end(content)
        }
    })

})
const PORT = process.env.PORT || 3000

app.listen(PORT, () => {
    console.log(`Listening on port ${PORT}`)
})