มือใหม่หัดเขียน NodeJs ผลัดมาตั้งนาน กว่าจะได้โอกาส

const express = require('express');
const session = require('express-session');
const bodyParser = require('body-parser');
const router = express.Router();

var https = require('https'), fs = require('fs');
var port = process.env.PORT || 443;
const options = {
  key:  fs.readFileSync('../Certificate/private.key'),
  cert: fs.readFileSync('../Certificate/certificate.crt')
};
const favicon = fs.readFileSync('../favicon.ico'); // read file

const app = express();
//app.use(session({secret: 'ssshhhhh',saveUninitialized: true,resave: true}));
app.use(session({secret: 'HKEncript', saveUninitialized: true, resave: true}));
app.use(bodyParser.json());      
app.use(bodyParser.urlencoded({extended: true}));
app.use(express.static(__dirname + '/views'));

var sess; // global session, NOT recommended

router.get('/',(req,res) => {
	sess = req.session;
	if(sess.email) {
		return res.redirect('/admin');
	}
	res.sendFile('index.html');
});

router.post('/login',(req,res) => {
	sess = req.session;
	sess.email = req.body.email;
	res.end('done');
});

router.get('/favicon.ico',(req,res) => {
	res.statusCode = 200;
	res.setHeader('Content-Length', favicon.length);
	res.setHeader('Content-Type', 'image/x-icon');
	res.setHeader("Cache-Control", "public, max-age=2592000"); // expiers after a month
	res.setHeader("Expires", new Date(Date.now() + 2592000000).toUTCString());
	res.end(favicon);
});

router.get('/admin',(req,res) => {
	sess = req.session;
	if(sess.email) {
		res.write(`<h1>Hello ${sess.email} </h1><br>`);
		res.end('<a href='+'/logout'+'>Logout</a>');
	}
	else {
		res.write('<h1>Please login first.</h1>');
		res.end('<a href='+'/'+'>Login</a>');
	}
});

router.get('/logout',(req,res) => {
	req.session.destroy((err) => {
		if(err) {
			return console.log(err);
		}
		res.redirect('/');
	});
});
app.use('/', router);
var server = https.createServer(options, app);
server.listen( port, function () {
    console.log( 'Hello Web Server listening on port ' + server.address().port );
});