<?php
/**
 * 前端：渲染混装产品的自定义 add-to-cart 表单、校验并加入购物车。
 */
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() {
        // 加载自定义的混装产品页面模板
        add_filter('template_include', array($this, 'use_bundle_template'), 99);

        // 处理加入购物车：校验数量并打包所选组件数据
        add_filter('woocommerce_add_to_cart_validation', array($this, 'validate_add_to_cart'), 10, 6);
        add_filter('woocommerce_add_cart_item_data', array($this, 'add_cart_item_data'), 10, 3);

        // 在购物车/订单中显示组件摘要
        add_filter('woocommerce_get_item_data', array($this, 'display_cart_item_data'), 10, 2);

        // 结算前动态调整价格
        add_action('woocommerce_before_calculate_totals', array($this, 'adjust_bundle_price'), 20, 1);

        // 为混装产品页增加 body class，便于主题兼容样式控制
        add_filter('body_class', array($this, 'filter_body_class'));

        // 从 woocommerce_single_product_summary 钩子中移除默认的 add-to-cart
        add_action('init', array($this, 'remove_default_add_to_cart'));
    }

    /**
     * 移除默认的 add-to-cart 按钮，因为我们的模板会自己处理
     */
    public function remove_default_add_to_cart() {
        remove_action('woocommerce_single_product_summary', 'woocommerce_template_single_add_to_cart', 30);
    }

    /**
     * 如果是混装产品页面，则加载我们的自定义模板。
     */
    public function use_bundle_template($template) {
        if (is_singular('product')) {
            global $post;
            $product = wc_get_product($post->ID);
            if ($product && $product->get_type() === Yoone_Product_Bundles::TYPE) {
                // 加载插件内的完整页面模板
                $new_template = YOONE_PB_PATH . 'templates/single-product-yoone-bundle.php';
                if (file_exists($new_template)) {
                    return $new_template;
                }
            }
        }
        return $template;
    }

    /**
     * 在混装产品页增加 body class。
     */
    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;
    }

    /**
     * 校验混装产品加入购物车：至少选择一个组件。
     */
    public function validate_add_to_cart($passed, $product_id, $quantity, $variation_id = null, $variations = null, $cart_item_data = null) {
        $product = wc_get_product($product_id);
        if ($product->get_type() !== Yoone_Product_Bundles::TYPE) {
            return $passed;
        }

        $config = Yoone_Product_Bundles::get_bundle_config($product);
        $min_qty = max(1, absint($config['min_qty']));

        $components = !empty($_POST['yoone_bundle_components']) ? $_POST['yoone_bundle_components'] : array();
        $total_qty = 0;
        foreach ($components as $comp_id => $qty) {
            $qty = absint($qty);
            if ($qty > 0) {
                $total_qty += $qty;
            }
        }

        if ($total_qty < $min_qty) {
            wc_add_notice(sprintf(__('您需要至少选择 %d 件商品才能将此混装包加入购物车。', 'yoone-product-bundles'), $min_qty), 'error');
            return false;
        }

        return $passed;
    }

    /**
     * 将混装组件数据添加到购物车项目。
     */
    public function add_cart_item_data($cart_item_data, $product_id, $variation_id) {
        $product = wc_get_product($product_id);
        if ($product->get_type() !== Yoone_Product_Bundles::TYPE) {
            return $cart_item_data;
        }

        if (isset($_POST['yoone_bundle_components'])) {
            $components = array();
            foreach ($_POST['yoone_bundle_components'] as $comp_id => $qty) {
                $qty = absint($qty);
                if ($qty > 0) {
                    $components[absint($comp_id)] = $qty;
                }
            }
            if (!empty($components)) {
                $cart_item_data['yoone_bundle_components'] = $components;
            }
        }

        return $cart_item_data;
    }

    /**
     * 在购物车和订单中显示混装组件的摘要。
     */
    public function display_cart_item_data($item_data, $cart_item) {
        if (empty($cart_item['yoone_bundle_components'])) {
            return $item_data;
        }

        $value = "";
        foreach ($cart_item['yoone_bundle_components'] as $pid => $qty) {
            $product = wc_get_product($pid);
            if ($product) {
                $value .= $product->get_name() . ' &times; ' . $qty . "; ";
            }
        }

        $item_data[] = array(
            'key'     => __('混装明细', 'yoone-product-bundles'),
            'value'   => rtrim($value, "; "),
            'display' => ''
        );

        return $item_data;
    }

    /**
     * 在将商品添加到购物车之前，根据所选组件动态计算混装产品的总价。
     */
    public function adjust_bundle_price($cart) {
        if (is_admin() && !defined('DOING_AJAX')) return;

        foreach ($cart->get_cart() as $cart_item_key => $cart_item) {
            if (isset($cart_item['yoone_bundle_components'])) {
                $total_price = 0;
                foreach ($cart_item['yoone_bundle_components'] as $pid => $qty) {
                    $product = wc_get_product($pid);
                    if ($product) {
                        $total_price += (float) $product->get_price() * $qty;
                    }
                }
                $cart_item['data']->set_price($total_price);
            }
        }
    }
}