35595-vm/cart.php

<?php
require_once 'header.php';
require_once 'db/config.php';

$cart_items = [];
$total = 0;

if (isset($_SESSION['cart']) && !empty($_SESSION['cart'])) {
    $product_ids = array_keys($_SESSION['cart']);
    $placeholders = implode(',', array_fill(0, count($product_ids), '?'));

    $pdo = db();
    $stmt = $pdo->prepare("SELECT * FROM products WHERE id IN ($placeholders)");
    $stmt->execute($product_ids);
    $products = $stmt->fetchAll();

    foreach ($products as $product) {
        $product_id = $product['id'];
        $quantity = $_SESSION['cart'][$product_id];
        $subtotal = $product['price'] * $quantity;
        $total += $subtotal;

        $cart_items[] = [
            'id' => $product_id,
            'name' => $product['name'],
            'price' => $product['price'],
            'quantity' => $quantity,
            'subtotal' => $subtotal
        ];
    }
}

if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['update_cart'])) {
    foreach ($_POST['quantities'] as $product_id => $quantity) {
        if ($quantity > 0) {
            $_SESSION['cart'][$product_id] = (int)$quantity;
        } else {
            unset($_SESSION['cart'][$product_id]);
        }
    }
    header("Location: cart.php");
    exit;
}

if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['checkout'])) {
    if (!isset($_SESSION['user_id'])) {
        header("Location: login.php");
        exit;
    }

    if (empty($cart_items)) {
        header("Location: shop.php");
        exit;
    }

    $pdo = db();
    
    try {
        $pdo->beginTransaction();

        // Check if user has enough balance
        $stmt = $pdo->prepare("SELECT balance FROM users WHERE id = ?");
        $stmt->execute([$_SESSION['user_id']]);
        $user = $stmt->fetch();

        if ($user['balance'] < $total) {
            // Not enough balance
            $pdo->rollBack();
            // Redirect to cart with an error message
            header("Location: cart.php?error=balance");
            exit;
        }
        
        // Create order
        $stmt = $pdo->prepare("INSERT INTO orders (user_id, total) VALUES (?, ?)");
        $stmt->execute([$_SESSION['user_id'], $total]);
        $order_id = $pdo->lastInsertId();

        // Create order items
        $stmt = $pdo->prepare("INSERT INTO order_items (order_id, product_id, quantity, price) VALUES (?, ?, ?, ?)");
        foreach ($cart_items as $item) {
            $stmt->execute([$order_id, $item['id'], $item['quantity'], $item['price']]);
        }

        // Deduct balance from user
        $new_balance = $user['balance'] - $total;
        $stmt = $pdo->prepare("UPDATE users SET balance = ? WHERE id = ?");
        $stmt->execute([$new_balance, $_SESSION['user_id']]);

        $pdo->commit();

        // Clear cart
        unset($_SESSION['cart']);

        // Redirect to a success page
        header("Location: order_success.php?order_id=" . $order_id);
        exit;

    } catch (Exception $e) {
        $pdo->rollBack();
        // Log the error
        error_log($e->getMessage());
        // Redirect to cart with a generic error
        header("Location: cart.php?error=checkout");
        exit;
    }
}
?>

<header class="hero text-center">
    <div class="container">
        <h1 class="display-4">Shopping Cart</h1>
    </div>
</header>

<main class="container my-5">
    <?php if (isset($_GET['error'])): ?>
        <div class="alert alert-danger">
            <?php if ($_GET['error'] === 'balance'): ?>
                You do not have enough balance to complete this purchase.
            <?php else: ?>
                An error occurred during checkout. Please try again.
            <?php endif; ?>
        </div>
    <?php endif; ?>

    <?php if (empty($cart_items)): ?>
        <div class="text-center">
            <p class="lead">Your cart is empty.</p>
            <a href="shop.php" class="btn btn-primary">Continue Shopping</a>
        </div>
    <?php else: ?>
        <form action="cart.php" method="POST">
            <table class="table">
                <thead>
                    <tr>
                        <th>Product</th>
                        <th>Price</th>
                        <th>Quantity</th>
                        <th>Subtotal</th>
                    </tr>
                </thead>
                <tbody>
                    <?php foreach ($cart_items as $item): ?>
                        <tr>
                            <td><?php echo htmlspecialchars($item['name']); ?></td>
                            <td>$<?php echo htmlspecialchars(number_format($item['price'], 2)); ?></td>
                            <td>
                                <input type="number" name="quantities[<?php echo $item['id']; ?>]" value="<?php echo $item['quantity']; ?>" min="0" class="form-control" style="width: 100px;">
                            </td>
                            <td>$<?php echo htmlspecialchars(number_format($item['subtotal'], 2)); ?></td>
                        </tr>
                    <?php endforeach; ?>
                </tbody>
            </table>

            <div class="d-flex justify-content-between align-items-center">
                <button type="submit" name="update_cart" class="btn btn-secondary">Update Cart</button>
                <p class="fs-4">Total: $<?php echo htmlspecialchars(number_format($total, 2)); ?></p>
            </div>
        </form>
        
        <form action="cart.php" method="POST" class="mt-3 text-end">
            <button type="submit" name="checkout" class="btn btn-primary btn-lg">Checkout</button>
        </form>
    <?php endif; ?>
</main>

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