index.js

/*This code uses express and ejs to render the index.ejs file from the views folder.
 The app.listen(8080) function listens for requests on port 8080.
 app.get is basically used to specify what function should execute when there is a GET request to the given path.*/


var express = require('express');
var ejs = require('ejs');
var bodyParser = require('body-parser');
var mysql = require('mysql');
var session = require('express-session');


mysql.createConnection({
    host: "localhost",
    user: "root",
    password: "",
    database: "node_project"
})

var app = express(); //instance of an Express application

//configure the Express app.
app.use(express.static('public'));
app.set('view engine', 'ejs'); //use ejs as the view engine

app.listen(8080); //starts the server on a port.
app.use(bodyParser.urlencoded({ extended: true }));
app.use(session({ secret: "secret" }))


function isProductInCart(cart, id) {
    for (let i = 0; i < cart.length; i++) {
        if (cart[i].id == id) {
            return true;
        }
    }
    return false;
}

function calculateTotal(cart, req) {
    var total = 0;
    for (let i = 0; i < cart.length; i++) {
        if (cart[i].sale_price) {
            total = total + (cart[i].sale_price * cart[i].quantity);
        } else {
            total = total + (cart[i].price * cart[i].quantity);
        }
    }
    req.session.total = total;
    return total;
}


//localhost:8080
//app.get is a route handler for GET requests to the given path.
app.get('/', function(req, res) {
    //render the index.ejs file
    var con = mysql.createConnection({
        host: "localhost",
        user: "root",
        password: "",
        database: "node_project"
    })
    con.query("SELECT * FROM products", (err, result) => {
        res.render('pages/index', { result: result });
    })

});

app.post('/add_to_cart', function(req, res) {
    var id = req.body.id;
    var name = req.body.name;
    var price = req.body.price;
    var sale_price = req.body.sale_price;
    var quantity = req.body.quantity;
    var image = req.body.image;
    var product = { id: id, name: name, price: price, sale_price: sale_price, quantity: quantity, image: image };

    if (req.session.cart) {
        var cart = req.session.cart;

        if (!isProductInCart(cart, id)) {
            cart.push(product);
        }
    } else {
        req.session.cart = [product];
        var cart = req.session.cart;
    }

    //to calculate total
    calculateTotal(cart, req);

    res.redirect('/cart');
});


app.get('/cart', function(req, res) {
    var cart = req.session.cart;
    var total = req.session.total;

    res.render('pages/cart', { cart: cart, total: total });
});


app.post('/remove_product', function(req, res) {

    var id = req.body.id;
    var cart = req.session.cart;

    for (let i = 0; i < cart.length; i++) {
        if (cart[i].id == id) {
            cart.splice(cart.indexOf(i), 1);
        }
    }

    //re-calculate total
    calculateTotal(cart, req);
    res.redirect('/cart');
});


app.post('/edit_product_quantity', function(req, res) {
    //get values from the inputs
    var id = req.body.id;
    var quantity = req.body.quantity;
    var increase_btn = req.body.increase_product_quantity_btn;
    var decrease_btn = req.body.decrease_product_quantity_btn;

    var cart = req.session.cart;

    if (increase_btn) {
        for (let i = 0; i < cart.length; i++) {
            if (cart[i].id == id) {
                if (cart[i].quantity > 0) {
                    cart[i].quantity = parseInt(cart[i].quantity) + 1;
                }
            }
        }
    }

    //similarly for decrease
    if (decrease_btn) {
        for (let i = 0; i < cart.length; i++) {
            if (cart[i].id == id) {
                if (cart[i].quantity > 1) {
                    cart[i].quantity = parseInt(cart[i].quantity) - 1;
                }
            }
        }
    }

    calculateTotal(cart, req);
    res.redirect('/cart');
});

app.get('/checkout', function(req, res) {
    var total = req.session.total;
    res.render('pages/checkout', { total: total });
});

app.post('/place_order', function(req, res) {

    var name = req.body.name;
    var email = req.body.email;
    var phone = req.body.phone;
    var city = req.body.city;
    var address = req.body.address;
    var cost = req.session.total;
    var status = "not paid";
    var date = new Date();
    var products_ids = "";

    var con = mysql.createConnection({
        host: "localhost",
        user: "root",
        password: "",
        database: "node_project"
    })

    var cart = req.session.cart;
    for (let i = 0; i < cart.length; i++) {
        products_ids = products_ids + "," + cart[i].id;
    }

    con.connect((err) => {
        if (err) {
            console.log(err)
        } else {
            var query = "INSERT INTO orders(cost, name, email, status, city, address, phone, date, products_ids) VALUES ?";
            var values = [
                [cost, name, email, status, city, address, phone, date, products_ids]
            ];
            con.query(query, [values], (err, result) => {

                for (let i = 0; i < cart.length; i++) {
                    var query = "INSERT INTO order_items (order_id, product_id, product_name, product_price, product_image, product_quantity, order_date) VALUES ?";
                    var values = [
                        [id, cart[i].id, cart[i].name, cart[i].price, cart[i].image, cart[i].quantity, new Date()]
                    ];
                    con.query(query, [values], (err, result) => {})
                }

                res.redirect('/payment')
            });
        }
    });

});

app.get('/payment', function(req, res) {
    res.render('pages/payment');
});