cart.php

<?php include 'config.php';
$pdo = pdo_connect_mysql();
if (session_id() == '' || !isset($_SESSION) || session_status() === PHP_SESSION_NONE) { //megnézi fut e már session
	session_start(); // ha nem, indít egy sessiont
}

// If the user clicked the add to cart button on the product page we can check for the form data
if (isset($_POST['product_id'], $_POST['quantity']) && is_numeric($_POST['product_id']) && is_numeric($_POST['quantity'])) {
	// Set the post variables so we easily identify them, also make sure they are integer
	$product_id = (int)$_POST['product_id'];
	$quantity = (int)$_POST['quantity'];
	// Prepare the SQL statement, we basically are checking if the product exists in our databaser
	$stmt = $pdo->prepare('SELECT * FROM products WHERE id = ?');
	$stmt->execute([$_POST['product_id']]);
	// Fetch the product from the database and return the result as an Array
	$product = $stmt->fetch(PDO::FETCH_ASSOC);
	// Check if the product exists (array is not empty)
	if ($product && $quantity > 0) {
		// Product exists in database, now we can create/update the session variable for the cart
		if (isset($_SESSION['cart']) && is_array($_SESSION['cart'])) {
			if (array_key_exists($product_id, $_SESSION['cart'])) {
				// Product exists in cart so just update the quanity
				$_SESSION['cart'][$product_id] += $quantity;
			} else {
				// Product is not in cart so add it
				$_SESSION['cart'][$product_id] = $quantity;
			}
		} else {
			// There are no products in cart, this will add the first product to cart
			$_SESSION['cart'] = array($product_id => $quantity);
		}
	}
	// Prevent form resubmission...
}

// Remove product from cart, check for the URL param "remove", this is the product id, make sure it's a number and check if it's in the cart
if (isset($_GET['remove']) && is_numeric($_GET['remove']) && isset($_SESSION['cart']) && isset($_SESSION['cart'][$_GET['remove']])) {
	// Remove the product from the shopping cart
	unset($_SESSION['cart'][$_GET['remove']]);
}

// Update product quantities in cart if the user clicks the "Update" button on the shopping cart page
if (isset($_POST['update']) && isset($_SESSION['cart'])) {
	// Loop through the post data so we can update the quantities for every product in cart
	foreach ($_POST as $k => $v) {
		if (strpos($k, 'quantity') !== false && is_numeric($v)) {
			$id = str_replace('quantity-', '', $k);
			$quantity = (int)$v;
			// Always do checks and validation
			if (is_numeric($id) && isset($_SESSION['cart'][$id]) && $quantity > 0) {
				// Update new quantity
				$_SESSION['cart'][$id] = $quantity;
			}
		}
	}
	// Prevent form resubmission...
	//header('location: cart.php');
	//exit;
}

// Send the user to the place order page if they click the Place Order button, also the cart should not be empty
if (isset($_POST['checkout']) && isset($_SESSION['cart']) && !empty($_SESSION['cart'])) {
	header('Location: checkout.php');
	//unset($_SESSION['cart']);
	exit;
}

// Check the session variable for products in cart
$products_in_cart = isset($_SESSION['cart']) ? $_SESSION['cart'] : array();
$products = array();
$subtotal = 0.00;
// If there are products in cart
if ($products_in_cart) {
	// There are products in the cart so we need to select those products from the database
	// Products in cart array to question mark string array, we need the SQL statement to include IN (?,?,?,...etc)
	$array_to_question_marks = implode(',', array_fill(0, count($products_in_cart), '?'));
	$stmt = $pdo->prepare('SELECT * FROM products WHERE id IN (' . $array_to_question_marks . ')');
	// We only need the array keys, not the values, the keys are the id's of the products
	$stmt->execute(array_keys($products_in_cart));
	// Fetch the products from the database and return the result as an Array
	$products = $stmt->fetchAll(PDO::FETCH_ASSOC);
	// Calculate the subtotal
	foreach ($products as $product) {
		$subtotal += (float)$product['price'] * (int)$products_in_cart[$product['id']];
	}
}
include 'topnav.php';
?>

<!-- Breadcrumb Start -->
<div class="container-fluid">
	<div class="row px-xl-5">
		<div class="col-12">
			<nav class="breadcrumb bg-white mb-30">
				<a class="breadcrumb-item text-dark" href="index.php">Home</a>
				<span class="breadcrumb-item active">Shopping Cart</span>
			</nav>
		</div>
	</div>
</div>
<!-- Breadcrumb End -->

<!-- Cart Start -->
<div class="container fluid">
	<h1 class="d-flex justify-content-center">Shopping Cart</h1><br>
	<h1 class="section-title position-relative"></h1>
	<form action="cart.php" method="post">
		<div class="col-lg-12 d-flex justify-content-center">
			<table class="mx-5 table table-white table-borderless text-center mb-5">
				<thead>
					<tr>
						<td colspan="2">Product</td>
						<td>Price</td>
						<td>Quantity</td>
						<td>Total</td>
					</tr>
				</thead>
				<tbody>
					<?php if (empty($products)) : ?>
						<tr>
							<td colspan="5" style="text-align:center; padding-left:150px">You have no products added in your Shopping Cart</td>
						</tr>
					<?php else : ?>
						<?php foreach ($products as $product) : ?>
							<tr>
								<div>
									<td>
										<a href="product.php?id=<?= $product['id'] ?>">
											<img src="img/<?= $product['image'] ?>" width="50" height="50" alt="<?= $product['name'] ?>">
										</a>
									</td>
									<td>
										<a href="product.php?id=<?= $product['id'] ?>"><?= $product['name'] ?></a>
										<br>
										<a href="cart.php?remove=<?= $product['id'] ?>" class="remove">Remove</a>
									</td>
								</div>
								<td><?= $product['price'] ?>&euro;</td>
								<td>
									<input type="number" name="quantity-<?= $product['id'] ?>" value="<?= $products_in_cart[$product['id']] ?>" placeholder="Quantity" required>
								</td>
								<td><?php
									$value = $product['price'] * $products_in_cart[$product['id']];
									if ($value != 0) {
										echo $value;
									} ?> &euro;
								</td>
							</tr>
						<?php endforeach; ?>
					<?php endif; ?>
				</tbody>
			</table>
			<div class="mx-2">
				<h3 class="text-black">Subtotal</h3>
				<i class="text-black d-flex justify-content-center" style="margin-top: 30px;"><?= $subtotal;
																								$_SESSION['subtotal'] = $subtotal; ?>&euro;</i>
			</div>
		</div>
		<div class='d-flex justify-content-center'>
			<div>
				<input class='btn btn-black my-2' type='submit' value='Update Quantity' name='update'>
				<a href='checkout.php'><input class='btn btn-black' type='submit' value='Checkout' name='checkout'></a>
			</div>
		</div>
	</form>
</div>
<!-- Cart End -->

<?php include 'footer.php'; ?>