<?php
/**
 * 前端：为混装产品渲染自定义的“添加到购物车”表单，并处理验证和加入购物车的逻辑。
 */
defined('ABSPATH') || exit;

class Yoone_Product_Bundles_Frontend {

    private static $_instance = null;

    public static function instance() {
        if (is_null(self::$_instance)) {
            self::$_instance = new self();
        }
        return self::$_instance;
    }

    private function __construct() {
        $this->setup_hooks();
    }

    /**
     * 设置所有与前端相关的钩子。
     */
    public function setup_hooks() {
        // Handle the custom add-to-cart process for bundles
        add_filter('woocommerce_add_to_cart_validation', array($this, 'process_bundle_add_to_cart'), 10, 3);

        // When a bundle container is removed, remove its children.
        add_action('woocommerce_cart_item_removed', array($this, 'remove_bundle_children'), 10, 2);

        // Hide the "remove" link for child items in the cart.
        add_filter('woocommerce_cart_item_remove_link', array($this, 'hide_child_remove_link'), 10, 2);
        
        // In the cart, show which bundle a child item belongs to.
        add_filter('woocommerce_get_item_data', array($this, 'display_child_bundle_link'), 10, 2);

        // Add a body class to the bundle product page for easier styling.
        add_filter('body_class', array($this, 'filter_body_class'));

        // Replace the default "Add to Cart" button with our custom form.
        add_action('woocommerce_single_product_summary', array($this, 'remove_default_add_to_cart_for_bundle'), 29);
        add_action('woocommerce_single_product_summary', array($this, 'render_bundle_add_to_cart_form'), 30);
    }

    /**
     * Hijack the add-to-cart process for bundle products.
     * Validates the submission, then adds the container and all child products to the cart.
     *
     * @return bool False to prevent the default add-to-cart action.
     */
    public function process_bundle_add_to_cart($passed, $product_id, $quantity) {
        $product = wc_get_product($product_id);
        if (!$product || $product->get_type() !== Yoone_Product_Bundles::TYPE) {
            return $passed; // Not our product, pass through.
        }

        // 1. Validation
        $config = Yoone_Product_Bundles::get_bundle_config($product);
        $min_qty = max(1, absint($config['min_qty']));
        $components = !empty($_POST['yoone_bundle_components']) ? (array) $_POST['yoone_bundle_components'] : array();
        
        $total_qty = 0;
        $clean_components = array();
        foreach ($components as $comp_id => $qty) {
            $qty = absint($qty);
            if ($qty > 0) {
                $total_qty += $qty;
                $clean_components[absint($comp_id)] = $qty;
            }
        }

        if ($total_qty < $min_qty) {
            wc_add_notice(sprintf(__('You need to select at least %d items to add this bundle to your cart.', 'yoone-product-bundles'), $min_qty), 'error');
            return false;
        }

        // 2. Add items to cart
        try {
            $bundle_container_id = uniqid('bundle_');

            // Add the main bundle product (as a 0-price container)
            WC()->cart->add_to_cart($product_id, 1, 0, array(), array('yoone_bundle_container_id' => $bundle_container_id));

            // Add child components
            foreach ($clean_components as $comp_id => $qty) {
                WC()->cart->add_to_cart($comp_id, $qty, 0, array(), array(
                    'yoone_bundle_parent_id' => $bundle_container_id,
                    'yoone_bundle_parent_product_id' => $product_id
                ));
            }
            
            // Set success message and redirect
            wc_add_to_cart_message(array($product_id => 1), true);
            add_filter('woocommerce_add_to_cart_redirect', function() { return wc_get_cart_url(); });

        } catch (Exception $e) {
            wc_add_notice($e->getMessage(), 'error');
            return false;
        }

        // Prevent default add-to-cart for the main product
        return false;
    }

    /**
     * When a cart item is removed, check if it's a bundle container.
     * If so, find and remove all its child items.
     */
    public function remove_bundle_children($removed_cart_item_key, $cart) {
        $removed_item = $cart->get_removed_cart_items()[$removed_cart_item_key];
        
        if (isset($removed_item['yoone_bundle_container_id'])) {
            $bundle_container_id = $removed_item['yoone_bundle_container_id'];
            
            foreach ($cart->get_cart() as $cart_item_key => $cart_item) {
                if (isset($cart_item['yoone_bundle_parent_id']) && $cart_item['yoone_bundle_parent_id'] === $bundle_container_id) {
                    $cart->remove_cart_item($cart_item_key);
                }
            }
        }
    }

    /**
     * Hide the remove link for child items of a bundle.
     */
    public function hide_child_remove_link($link, $cart_item_key) {
        $cart_item = WC()->cart->get_cart_item($cart_item_key);
        if (isset($cart_item['yoone_bundle_parent_id'])) {
            return '';
        }
        return $link;
    }

    /**
     * For child items, add a meta line in the cart to link back to the parent bundle.
     */
    public function display_child_bundle_link($item_data, $cart_item) {
        if (isset($cart_item['yoone_bundle_parent_product_id'])) {
            $parent_product = wc_get_product($cart_item['yoone_bundle_parent_product_id']);
            if ($parent_product) {
                $item_data[] = array(
                    'key'     => __('Part of', 'yoone-product-bundles'),
                    'value'   => $parent_product->get_name(),
                );
            }
        }
        return $item_data;
    }

    /**
     * Remove the default "Add to Cart" button for bundle products only.
     */
    public function remove_default_add_to_cart_for_bundle() {
        global $product;
        if ($product && $product->get_type() === Yoone_Product_Bundles::TYPE) {
            remove_action('woocommerce_single_product_summary', 'woocommerce_template_single_add_to_cart', 30);
        }
    }

    /**
     * Render the custom "Add to Cart" form for bundle products.
     */
    public function render_bundle_add_to_cart_form() {
        global $product;
        if ($product && $product->get_type() === Yoone_Product_Bundles::TYPE) {
            wc_get_template('global/yoone-bundle-form.php', array(), '', YOONE_PB_PATH . 'templates/');
        }
    }

    /**
     * Add a body class for bundle product pages.
     */
    public function filter_body_class($classes) {
        global $post;
        if (is_singular('product') && $post) {
            $product = wc_get_product($post->ID);
            if ($product && $product->get_type() === Yoone_Product_Bundles::TYPE) {
                $classes[] = 'yoone-bundle-product';
            }
        }
        return $classes;
    }
}