app.js

const express = require('express');
const mysql = require('mysql');
const session = require('express-session');
const app = express();

app.use(express.static('public'));
app.use(express.urlencoded({
    extended: false
}));

const connection = mysql.createConnection({
    host: 'db4free.net' || localhost,
    user: 'prasetiyo' || root,
    password: 'yourpassword',
    database: 'prasetiyo_blog' || blog
});

app.use(
    session({
        secret: 'my_secret_key',
        resave: false,
        saveUninitialized: false,
    })
);

app.use((req, res, next) => {
    if (req.session.userId === undefined) {
        res.locals.username = 'Visitor';
        res.locals.isLoggedIn = false;
    } else {
        res.locals.username = req.session.username;
        res.locals.isLoggedIn = true;
    }
    next();
});

app.get('/', (req, res) => {
    res.render('top.ejs');
});

app.get('/list', (req, res) => {
    connection.query(
        'SELECT * FROM articles',
        (error, results) => {
            res.render('list.ejs', {
                articles: results
            });
        }
    );
});

app.get('/article/:id', (req, res) => {
    const id = req.params.id;
    connection.query(
        'SELECT * FROM articles WHERE id = ?',
        [id],
        (error, results) => {
            res.render('article.ejs', {
                article: results[0]
            });
        }
    );
});

app.get('/signup', (req, res) => {
    res.render('signup.ejs', {
        errors: []
    });
});

app.post('/signup',
    (req, res, next) => {
        console.log('Pemeriksaan nilai input kosong');
        const username = req.body.username;
        const email = req.body.email;
        const password = req.body.password;
        const errors = [];

        if (username === '') {
            errors.push('Nama Pengguna kosong');
        }

        if (email === '') {
            errors.push('Email kosong');
        }

        if (password === '') {
            errors.push('Kata Sandi kosong');
        }

        if (errors.length > 0) {
            res.render('signup.ejs', {
                errors: errors
            });
        } else {
            next();
        }
    },
    (req, res, next) => {
        console.log('Pemeriksaan email duplikat');
        const email = req.body.email;
        const errors = [];

        connection.query(
            'SELECT * FROM users WHERE email = ?',
            [email],
            (error, results) => {
                if (results.length > 0) {
                    errors.push('Gagal mendaftarkan pengguna');
                    res.render('signup.ejs', {
                        errors: errors
                    });

                } else {
                    next();

                }
            }
        );

    },
    (req, res) => {
        console.log('Pendaftaran');
        const username = req.body.username;
        const email = req.body.email;
        const password = req.body.password;
        connection.query(
            'INSERT INTO users (username, email, password) VALUES (?, ?, ?)',
            [username, email, password],
            (error, results) => {
                req.session.userId = results.insertId;
                req.session.username = username;
                res.redirect('/list');
            }
        );
    }
);

app.get('/login', (req, res) => {
    res.render('login.ejs');
});

app.post('/login', (req, res) => {
    const email = req.body.email;
    connection.query(
        'SELECT * FROM users WHERE email = ?',
        [email],
        (error, results) => {
            if (results.length > 0) {
                if (req.body.password === results[0].password) {
                    req.session.userId = results[0].id;
                    req.session.username = results[0].username;
                    res.redirect('/list');
                } else {
                    res.redirect('/login');
                }
            } else {
                res.redirect('/login');
            }
        }
    );
});

app.get('/logout', (req, res) => {
    req.session.destroy(error => {
        res.redirect('/list');
    });
});

app.listen(process.env.PORT || 3000);