document.addEventListener('DOMContentLoaded', function() {
    // Function to get cart items from local storage
    function getCartItems() {
        const cartItems = localStorage.getItem('cart');
        return cartItems ? JSON.parse(cartItems) : [];
    }

    // Function to set cart items in local storage
    function setCartItems(cartItems) {
        localStorage.setItem('cart', JSON.stringify(cartItems));
    }

    // Function to add an item to the cart
    function addToCart(productId, quantity) {
        const cartItems = getCartItems();
        const existingItem = cartItems.find(item => item.productId === productId);

        if (existingItem) {
            existingItem.quantity += quantity;
        } else {
            cartItems.push({ productId, quantity });
        }

        setCartItems(cartItems);
        updateCartUI();
    }

    // Function to update item quantity in the cart
    function updateQuantity(productId, quantity) {
        const cartItems = getCartItems();
        const itemIndex = cartItems.findIndex(item => item.productId === productId);

        if (itemIndex !== -1) {
            cartItems[itemIndex].quantity = quantity;
            if (cartItems[itemIndex].quantity <= 0) {
                cartItems.splice(itemIndex, 1); // Remove item if quantity is 0 or less
            }
            setCartItems(cartItems);
            updateCartUI();
        }
    }

    // Function to remove an item from the cart
    function removeItem(productId) {
        const cartItems = getCartItems();
        const itemIndex = cartItems.findIndex(item => item.productId === productId);

        if (itemIndex !== -1) {
            cartItems.splice(itemIndex, 1);
            setCartItems(cartItems);
            updateCartUI();
        }
    }

    // Function to calculate cart totals
    function calculateTotals() {
        const cartItems = getCartItems();
        let subtotal = 0;

        // Dummy product prices (replace with actual product data)
        const productPrices = {
            "1": 20.00,
            "2": 30.00,
            "3": 40.00
        };

        cartItems.forEach(item => {
            const productId = item.productId;
            const quantity = item.quantity;
            const price = productPrices[productId] || 0; // Get price from productPrices, default to 0
            subtotal += price * quantity;
        });

        const shipping = 5.00;
        const total = subtotal + shipping;

        return { subtotal, shipping, total };
    }

    // Function to display cart items in cart.html
    function displayCartItems() {
        const cartItems = getCartItems();
        const cartItemsContainer = document.getElementById('cart-items');

        if (cartItemsContainer) {
            cartItemsContainer.innerHTML = ''; // Clear existing items

            cartItems.forEach(item => {
                // Dummy product data (replace with actual product data)
                const productId = item.productId;
                const product = {
                    id: productId,
                    title: `Product ${productId}`,
                    price: 20.00,
                    image: `https://via.placeholder.com/100`
                };
                const cartItemDiv = document.createElement('div');
                cartItemDiv.classList.add('flex', 'items-center', 'border', 'border-gray-300', 'rounded-md', 'p-4');

                cartItemDiv.innerHTML = `
                    <img src="${product.image}" alt="Product Image" class="w-24 h-24 mr-4">
                    <div>
                        <h2 class="text-lg font-bold">${product.title}</h2>
                        <p class="text-gray-600">$${product.price.toFixed(2)}</p>
                        <div class="flex items-center mt-2">
                            <button class="bg-gray-200 px-2 py-1 rounded-md decrease-quantity" data-product-id="${product.id}">-</button>
                            <input type="number" value="${item.quantity}" class="w-16 text-center border border-gray-300 rounded-md mx-2 quantity-input" data-product-id="${product.id}">
                            <button class="bg-gray-200 px-2 py-1 rounded-md increase-quantity" data-product-id="${product.id}">+</button>
                            <button class="text-red-500 hover:text-red-700 ml-4 remove-item" data-product-id="${product.id}">Remove</button>
                        </div>
                    </div>
                `;

                cartItemsContainer.appendChild(cartItemDiv);
            });

            // Add event listeners to quantity buttons and remove buttons
            const decreaseButtons = document.querySelectorAll('.decrease-quantity');
            decreaseButtons.forEach(button => {
                button.addEventListener('click', function() {
                    const productId = this.dataset.productId;
                    const quantityInput = this.parentNode.querySelector('.quantity-input');
                    let quantity = parseInt(quantityInput.value);
                    quantity = Math.max(1, quantity - 1); // Ensure quantity is not less than 1
                    quantityInput.value = quantity;
                    updateQuantity(productId, quantity);
                });
            });

            const increaseButtons = document.querySelectorAll('.increase-quantity');
            increaseButtons.forEach(button => {
                button.addEventListener('click', function() {
                    const productId = this.dataset.productId;
                    const quantityInput = this.parentNode.querySelector('.quantity-input');
                    let quantity = parseInt(quantityInput.value);
                    quantity++;
                    quantityInput.value = quantity;
                    updateQuantity(productId, quantity);
                });
            });

            const removeButtons = document.querySelectorAll('.remove-item');
            removeButtons.forEach(button => {
                button.addEventListener('click', function() {
                    const productId = this.dataset.productId;
                    removeItem(productId);
                });
            });
        }
    }

    // Function to update the order summary in cart.html and checkout.html
    function updateOrderSummary() {
        const { subtotal, shipping, total } = calculateTotals();

        const subtotalElements = document.querySelectorAll('#subtotal');
        subtotalElements.forEach(element => element.textContent = `$${subtotal.toFixed(2)}`);

        const shippingElements = document.querySelectorAll('#shipping');
        shippingElements.forEach(element => element.textContent = `$${shipping.toFixed(2)}`);

        const totalElements = document.querySelectorAll('#total');
        totalElements.forEach(element => element.textContent = `$${total.toFixed(2)}`);
    }

    // Function to handle checkout
    function handleCheckout() {
        const checkoutForm = document.getElementById('checkout-form');
        if (checkoutForm) {
            checkoutForm.addEventListener('submit', function(event) {
                event.preventDefault(); // Prevent form submission

                // Simulate order processing
                const orderId = Math.floor(Math.random() * 1000000);

                // Store order ID in local storage
                localStorage.setItem('orderId', orderId);

                // Clear the cart
                setCartItems([]);

                // Redirect to confirmation page
                window.location.href = '/confirmation.html';
            });
        }
    }

    // Function to display order confirmation details
    function displayOrderConfirmation() {
        const orderId = localStorage.getItem('orderId');
        const orderIdElement = document.getElementById('order-id');

        if (orderIdElement) {
            orderIdElement.textContent = orderId;
        }
    }

    // Initialize the cart page
    if (window.location.pathname === '/cart.html') {
        displayCartItems();
        updateOrderSummary();
    }

    // Initialize the checkout page
    if (window.location.pathname === '/checkout.html') {
        updateOrderSummary();
        handleCheckout();
    }

    // Initialize the confirmation page
    if (window.location.pathname === '/confirmation.html') {
        displayOrderConfirmation();
    }
});

    // Function to get cart items from local storage
    function getCartItems() {
        const cartItems = localStorage.getItem('cart');
        return cartItems ? JSON.parse(cartItems) : [];
    }

    // Function to set cart items in local storage
    function setCartItems(cartItems) {
        localStorage.setItem('cart', JSON.stringify(cartItems));
    }

    // Function to add an item to the cart
    function addToCart(productId, quantity) {
        const cartItems = getCartItems();
        const existingItem = cartItems.find(item => item.productId === productId);

        if (existingItem) {
            existingItem.quantity += quantity;
        } else {
            cartItems.push({ productId, quantity });
        }

        setCartItems(cartItems);
        updateCartUI();
    }

    // Function to update item quantity in the cart
    function updateQuantity(productId, quantity) {
        const cartItems = getCartItems();
        const itemIndex = cartItems.findIndex(item => item.productId === productId);

        if (itemIndex !== -1) {
            cartItems[itemIndex].quantity = quantity;
            if (cartItems[itemIndex].quantity <= 0) {
                cartItems.splice(itemIndex, 1); // Remove item if quantity is 0 or less
            }
            setCartItems(cartItems);
            updateCartUI();
        }
    }

    // Function to remove an item from the cart
    function removeItem(productId) {
        const cartItems = getCartItems();
        const itemIndex = cartItems.findIndex(item => item.productId === productId);

        if (itemIndex !== -1) {
            cartItems.splice(itemIndex, 1);
            setCartItems(cartItems);
            updateCartUI();
        }
    }

    // Function to calculate cart totals
    function calculateTotals() {
        const cartItems = getCartItems();
        let subtotal = 0;

        // Dummy product prices (replace with actual product data)
        const productPrices = {
            "1": 20.00,
            "2": 30.00,
            "3": 40.00
        };

        cartItems.forEach(item => {
            const productId = item.productId;
            const quantity = item.quantity;
            const price = productPrices[productId] || 0; // Get price from productPrices, default to 0
            subtotal += price * quantity;
        });

        const shipping = 5.00;
        const total = subtotal + shipping;

        return { subtotal, shipping, total };
    }

    // Function to display cart items in cart.html
    function displayCartItems() {
        const cartItems = getCartItems();
        const cartItemsContainer = document.getElementById('cart-items');

        if (cartItemsContainer) {
            cartItemsContainer.innerHTML = ''; // Clear existing items

            cartItems.forEach(item => {
                // Dummy product data (replace with actual product data)
                const productId = item.productId;
                const product = {
                    id: productId,
                    title: `Product ${productId}`,
                    price: 20.00,
                    image: `https://via.placeholder.com/100`
                };
                const cartItemDiv = document.createElement('div');
                cartItemDiv.classList.add('flex', 'items-center', 'border', 'border-gray-300', 'rounded-md', 'p-4');

                cartItemDiv.innerHTML = `
                    <img src="${product.image}" alt="Product Image" class="w-24 h-24 mr-4">
                    <div>
                        <h2 class="text-lg font-bold">${product.title}</h2>
                        <p class="text-gray-600">$${product.price.toFixed(2)}</p>
                        <div class="flex items-center mt-2">
                            <button class="bg-gray-200 px-2 py-1 rounded-md decrease-quantity" data-product-id="${product.id}">-</button>
                            <input type="number" value="${item.quantity}" class="w-16 text-center border border-gray-300 rounded-md mx-2 quantity-input" data-product-id="${product.id}">
                            <button class="bg-gray-200 px-2 py-1 rounded-md increase-quantity" data-product-id="${product.id}">+</button>
                            <button class="text-red-500 hover:text-red-700 ml-4 remove-item" data-product-id="${product.id}">Remove</button>
                        </div>
                    </div>
                `;

                cartItemsContainer.appendChild(cartItemDiv);
            });

            // Add event listeners to quantity buttons and remove buttons
            const decreaseButtons = document.querySelectorAll('.decrease-quantity');
            decreaseButtons.forEach(button => {
                button.addEventListener('click', function() {
                    const productId = this.dataset.productId;
                    const quantityInput = this.parentNode.querySelector('.quantity-input');
                    let quantity = parseInt(quantityInput.value);
                    quantity = Math.max(1, quantity - 1); // Ensure quantity is not less than 1
                    quantityInput.value = quantity;
                    updateQuantity(productId, quantity);
                });
            });

            const increaseButtons = document.querySelectorAll('.increase-quantity');
            increaseButtons.forEach(button => {
                button.addEventListener('click', function() {
                    const productId = this.dataset.productId;
                    const quantityInput = this.parentNode.querySelector('.quantity-input');
                    let quantity = parseInt(quantityInput.value);
                    quantity++;
                    quantityInput.value = quantity;
                    updateQuantity(productId, quantity);
                });
            });

            const removeButtons = document.querySelectorAll('.remove-item');
            removeButtons.forEach(button => {
                button.addEventListener('click', function() {
                    const productId = this.dataset.productId;
                    removeItem(productId);
                });
            });
        }
    }

    // Function to update the order summary in cart.html and checkout.html
    function updateOrderSummary() {
        const { subtotal, shipping, total } = calculateTotals();

        const subtotalElements = document.querySelectorAll('#subtotal');
        subtotalElements.forEach(element => element.textContent = `$${subtotal.toFixed(2)}`);

        const shippingElements = document.querySelectorAll('#shipping');
        shippingElements.forEach(element => element.textContent = `$${shipping.toFixed(2)}`);

        const totalElements = document.querySelectorAll('#total');
        totalElements.forEach(element => element.textContent = `$${total.toFixed(2)}`);
    }

    // Function to handle checkout
    function handleCheckout() {
        const checkoutForm = document.getElementById('checkout-form');
        if (checkoutForm) {
            checkoutForm.addEventListener('submit', function(event) {
                event.preventDefault(); // Prevent form submission

                // Simulate order processing
                const orderId = Math.floor(Math.random() * 1000000);

                // Store order ID in local storage
                localStorage.setItem('orderId', orderId);

                // Clear the cart
                setCartItems([]);

                // Redirect to confirmation page
                window.location.href = '/confirmation.html';
            });
        }
    }

    // Function to display order confirmation details
    function displayOrderConfirmation() {
        const orderId = localStorage.getItem('orderId');
        const orderIdElement = document.getElementById('order-id');

        if (orderIdElement) {
            orderIdElement.textContent = orderId;
        }
    }

document.addEventListener('DOMContentLoaded', function() {
    // Initialize the cart page
    if (window.location.pathname === '/cart.html') {
        displayCartItems();
        updateOrderSummary();
    }

    // Initialize the checkout page
    if (window.location.pathname === '/checkout.html') {
        updateOrderSummary();
        handleCheckout();
    }

    // Initialize the confirmation page
    if (window.location.pathname === '/confirmation.html') {
        displayOrderConfirmation();
    }
});