<?php

/**
 * Antom Shomi Pay API
 *
 * 提供 WooCommerce 购物车、优惠券、地址、配送、订单和支付相关的 REST API 接口。
 *
 */

if (!defined('ABSPATH')) {
    exit; // Exit if accessed directly.
}

/**
 * REST API 控制器类
 *
 * 注册并处理 agent/v1 命名空间下的所有 API 端点。
 */
class Antom_Shomi_Pay_API
{

    /**
     * 构造函数 - 注册 REST API 路由钩子
     */
    public function __construct()
    {
        add_action('rest_api_init', array($this, 'register_routes'));
    }

    /**
     * 注册所有 REST API 路由
     *
     * 在 WordPress REST API 初始化时注册以下端点：
     * - 购物车：GET /cart, POST /cart/add, POST /cart/update, POST /cart/remove
     * - 地址：GET /address/fields, POST /address/save, GET /address/countries, GET /address/states
     * - 配送：POST /shipping/calculate, POST /shipping/shipping-methods
     * - 订单：POST /orders/get
     * - 支付：GET /payment/methods, POST /payment/process
     * - 优惠券：POST /coupon/available, POST /coupon/apply, GET /coupon/applied, POST /coupon/remove
     *
     * @return void
     */
    public function register_routes()
    {
        $namespace = 'agent/v1';

        // ======================
        // 购物车相关路由
        // ======================
        register_rest_route(
            $namespace,
            '/cart',
            array(
                'methods' => 'GET',
                'callback' => array(__CLASS__, 'get_cart'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
            )
        );

        register_rest_route(
            $namespace,
            '/cart/add',
            array(
                'methods' => 'POST',
                'callback' => array(__CLASS__, 'add_to_cart'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
                'args' => array(
                    'items' => array(
                        'required' => true,
                        'type' => 'array',
                    ),
                ),
            )
        );

        register_rest_route(
            $namespace,
            '/cart/update',
            array(
                'methods' => 'POST',
                'callback' => array(__CLASS__, 'update_cart_item'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
                'args' => array(
                    'items' => array(
                        'required' => true,
                        'type' => 'array',
                    ),
                ),
            )
        );

        register_rest_route(
            $namespace,
            '/cart/remove',
            array(
                'methods' => 'POST',
                'callback' => array(__CLASS__, 'remove_cart_item'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
                'args' => array(
                    'keys' => array(
                        'required' => true,
                        'type' => 'array',
                    ),
                ),
            )
        );

        // ======================
        // 地址相关路由
        // ======================
        register_rest_route(
            $namespace,
            '/address/fields',
            array(
                'methods' => 'GET',
                'callback' => array(__CLASS__, 'get_address_fields'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
            )
        );

        register_rest_route(
            $namespace,
            '/address/save',
            array(
                'methods' => 'POST',
                'callback' => array(__CLASS__, 'save_address'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
            )
        );

        register_rest_route(
            $namespace,
            '/address/countries',
            array(
                'methods' => 'GET',
                'callback' => array(__CLASS__, 'get_countries'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
            )
        );

        register_rest_route(
            $namespace,
            '/address/states',
            array(
                'methods' => 'GET',
                'callback' => array(__CLASS__, 'get_states'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
                'args' => array(
                    'country' => array(
                        'required' => true,
                        'type' => 'string',
                        'validate_callback' => function ($param) {
                            $countries = WC()->countries->get_countries();
                            return isset($countries[$param]);
                        },
                        'validate_callback_message' => 'Invalid country code.',
                    ),
                ),
            )
        );

        // ======================
        // 配送相关路由
        // ======================
        register_rest_route(
            $namespace,
            '/shipping/calculate',
            array(
                'methods' => 'POST',
                'callback' => array(__CLASS__, 'calculate_shipping'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
            )
        );

        register_rest_route(
            $namespace,
            '/shipping/shipping-methods',
            array(
                'methods' => 'POST',
                'callback' => array(__CLASS__, 'get_shipping_methods'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
            )
        );

        // ======================
        // 订单相关路由
        // ======================
        register_rest_route(
            $namespace,
            '/orders/get',
            array(
                'methods' => 'POST',
                'callback' => array(__CLASS__, 'get_orders'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
            )
        );

        // ======================
        // 支付相关路由
        // ======================
        register_rest_route(
            $namespace,
            '/payment/methods',
            array(
                'methods' => 'GET',
                'callback' => array(__CLASS__, 'get_payment_methods'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
            )
        );

        register_rest_route(
            $namespace,
            '/payment/process',
            array(
                'methods' => 'POST',
                'callback' => array(__CLASS__, 'process_checkout'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
            )
        );

        // ======================
        // 优惠券相关路由
        // ======================
        register_rest_route(
            $namespace,
            '/coupon/available',
            array(
                'methods' => 'POST',
                'callback' => array(__CLASS__, 'get_available_coupons'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
                'args' => array(
                    'ids' => array(
                        'required' => false,
                        'type' => 'array',
                    ),
                ),
            )
        );

        register_rest_route(
            $namespace,
            '/coupon/apply',
            array(
                'methods' => 'POST',
                'callback' => array(__CLASS__, 'apply_coupon'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
                'args' => array(
                    'code' => array(
                        'required' => true,
                    ),
                ),
            )
        );

        register_rest_route(
            $namespace,
            '/coupon/applied',
            array(
                'methods' => 'GET',
                'callback' => array(__CLASS__, 'get_applied_coupons'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
            )
        );

        register_rest_route(
            $namespace,
            '/coupon/remove',
            array(
                'methods' => 'POST',
                'callback' => array(__CLASS__, 'remove_coupon'),
                'permission_callback' => ['Antom_Shomi_Setup_Wizard', 'check_api_permission'],
                'args' => array(
                    'code' => array(
                        'required' => true,
                    ),
                ),
            )
        );
    }

    /**
     * 确保 WooCommerce session 和 cart 已正确初始化
     *
     * @return WP_REST_Response|void 初始化失败时返回错误响应，成功时无返回
     */
    protected static function ensure_woocommerce_session_and_cart()
    {
        // 检查 WooCommerce 是否已初始化
        if (!did_action('woocommerce_init')) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'WooCommerce is not ready'),
                200
            );
        }

        // REST API 请求中恢复用户身份（Cookie 认证需要 nonce 验证）
        if (!is_user_logged_in()) {
            // 通过 WordPress 核心过滤器从 cookie 中验证并设置当前用户
            $user_id = apply_filters('determine_current_user', 0);
            if ($user_id && $user_id > 0) {
                wp_set_current_user($user_id);
            }
        }

        // 初始化购物车和会话
        wc_load_cart();
        WC()->cart->get_cart();

        // 确保 customer 对象存在
        if (!WC()->customer) {
            WC()->customer = new WC_Customer(get_current_user_id(), true);
        }

        // 启动 WooCommerce session
        if (WC()->session && !WC()->session->has_session()) {
            WC()->session->set_customer_session_cookie(true);
        }

        // 登录用户确保 customer 对象关联正确的用户 ID
        if (is_user_logged_in() && WC()->customer) {
            $current_user_id = get_current_user_id();
            if (WC()->customer->get_id() !== $current_user_id) {
                // 重新创建 customer 对象以关联正确的用户
                WC()->customer = new WC_Customer($current_user_id, true);
            }
        }

        // 最终校验
        if (!WC()->cart || !WC()->customer) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Failed to load cart or customer.'),
                200
            );
        }
    }

    // ======================
    // 购物车管理
    // ======================

    /**
     * 获取当前购物车内容
     *
     * 返回购物车中所有商品、总价、折扣、运费等信息。
     * 包含商品名称、价格、数量、小计、是否虚拟商品、商品图片等详细信息。
     * 同时计算商品折扣和优惠券折扣。
     *
     * @return WP_REST_Response 购物车数据响应
     */
    public static function get_cart()
    {
        self::ensure_woocommerce_session_and_cart();

        try {
            WC()->cart->calculate_totals();
            $items = array();
            $decimals = wc_get_price_decimals();
            $product_discount_total = 0.0;

            // 遍历购物车商品
            foreach (WC()->cart->get_cart() as $item_key => $item) {
                $product = $item['data'];
                if (!$product) {
                    continue;
                }

                // 获取显示价格（已应用促销、税费等）
                $display_price = wc_get_price_to_display($product);
                $formatted_price = wc_format_decimal($display_price, $decimals);

                // 使用 line_total（含折扣）计算小计
                $subtotal = isset($item['line_total']) ? $item['line_total'] : ($item['line_subtotal'] ?? 0);
                $formatted_subtotal = wc_format_decimal($subtotal, $decimals);

                // 计算商品折扣（原价 - 现价）* 数量
                $regular_price = (float) $product->get_regular_price();
                $sale_price = (float) $product->get_price();
                if ($regular_price > $sale_price) {
                    $product_discount_total += ($regular_price - $sale_price) * (int) $item['quantity'];
                }

                $items[] = array(
                    'key' => $item_key,
                    'product_id' => $product->get_id(),
                    'name' => $product->get_name(),
                    'price' => $formatted_price,
                    'quantity' => (int) $item['quantity'],
                    'subtotal' => $formatted_subtotal,
                    'is_virtual' => (bool) $product->is_virtual(),
                    'type' => $product->get_type(),
                    'image' => wp_get_attachment_image_url($product->get_image_id(), 'woocommerce_thumbnail') ?: wc_placeholder_img_src('woocommerce_thumbnail'),
                );
            }

            $coupon_discount = WC()->cart->get_discount_total();
            $shipping_total  = WC()->cart->get_shipping_total();

            return new WP_REST_Response(
                array(
                    'success' => true,
                    'data' => array(
                        'items' => $items,
                        'total_raw' => (float) WC()->cart->get_total('edit'),
                        'total' => wc_price(WC()->cart->get_total('edit')),
                        'needs_shipping' => (bool) WC()->cart->needs_shipping(),
                        'coupon_discount' => wc_format_decimal($coupon_discount, $decimals),
                        'shipping_total' => wc_format_decimal($shipping_total, $decimals),
                        'product_discount' => wc_format_decimal($product_discount_total, $decimals),
                        'currency' => get_woocommerce_currency(),
                        'currency_symbol' => html_entity_decode(get_woocommerce_currency_symbol(), ENT_QUOTES, 'UTF-8'),
                    )
                ),
                200
            );
        } catch (Exception $e) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Failed to retrieve cart.'),
                200
            );
        }
    }

    /**
     * 添加商品到购物车
     *
     * @param WP_REST_Request $request 请求参数，包含 items 数
     * @return WP_REST_Response 添加结果响应，成功时返回更新后的购物车数据
     */
    public static function add_to_cart($request)
    {
        self::ensure_woocommerce_session_and_cart();

        $items = $request->get_param('items');
        $errors = array();

        // 参数校验
        if (!is_array($items) || empty($items)) {
            return new WP_REST_Response(
                array('success' => false, 'message' => "Invalid items: expected a non-empty array."),
                200
            );
        }

        // 逐个添加商品
        foreach ($items as $item) {
            $product_id = isset($item['product_id']) ? absint($item['product_id']) : 0;
            $quantity = isset($item['quantity']) ? absint($item['quantity']) : 1;

            $product = wc_get_product($product_id);
            if (!$product || !$product->is_purchasable()) {
                $errors[] = sprintf('Invalid product ID: %d', $product_id);
                continue;
            }

            $result = WC()->cart->add_to_cart($product_id, $quantity);
            if (!$result) {
                if ($product->is_type('variable')) {
                    // 可变商品需要 variation_id + attributes
                    $errors[] = sprintf('Failed to add product %d to cart, expected SKU ID but received SPU ID.', $product_id);
                } else {
                    $errors[] = sprintf('Failed to add product %d to cart.', $product_id);
                }
            }
        }

        WC()->cart->calculate_totals();
        WC()->cart->set_session();

        if (!empty($errors)) {
            return new WP_REST_Response(
                array('success' => false, 'message' => implode('; ', $errors)),
                200
            );
        }

        return self::get_cart();
    }

    /**
     * 更新购物车商品数量
     *
     * @param WP_REST_Request $request 请求参数，包含 items 数组
     * @return WP_REST_Response 更新结果响应，成功时返回更新后的购物车数据
     */
    public static function update_cart_item($request)
    {
        self::ensure_woocommerce_session_and_cart();

        $items = $request->get_param('items');
        $errors = array();

        // 参数校验
        if (!is_array($items) || empty($items)) {
            return new WP_REST_Response(
                array('success' => false, 'message' => "Invalid items: expected a non-empty array."),
                200
            );
        }

        // 逐个更新商品数量
        foreach ($items as $item) {
            $key = isset($item['key']) ? sanitize_text_field($item['key']) : '';
            $quantity = isset($item['quantity']) ? absint($item['quantity']) : 0;

            if ('' === $key || !isset(WC()->cart->cart_contents[$key])) {
                $errors[] = sprintf('Cart item not found: %s', $key);
                continue;
            }

            WC()->cart->set_quantity($key, $quantity, true);
        }

        WC()->cart->calculate_totals();
        WC()->cart->set_session();

        if (!empty($errors)) {
            return new WP_REST_Response(
                array('success' => false, 'message' => implode('; ', $errors)),
                200
            );
        }

        return self::get_cart();
    }

    /**
     * 批量从购物车中移除指定的商品。
     *
     * @param WP_REST_Request $request 请求参数，包含 keys 数组
     * @return WP_REST_Response 移除结果响应，成功时返回更新后的购物车数据
     */
    public static function remove_cart_item($request)
    {
        self::ensure_woocommerce_session_and_cart();

        $keys = $request->get_param('keys');
        $errors = array();

        // 参数校验
        if (!is_array($keys) || empty($keys)) {
            return new WP_REST_Response(
                array('success' => false, 'message' => "Invalid keys: expected a non-empty array."),
                200
            );
        }

        // 逐个移除商品
        foreach ($keys as $key) {
            $key = sanitize_text_field($key);
            if (!isset(WC()->cart->cart_contents[$key])) {
                $errors[] = sprintf('Cart item not found: %s', $key);
                continue;
            }

            WC()->cart->remove_cart_item($key);
        }

        WC()->cart->calculate_totals();
        WC()->cart->set_session();

        if (!empty($errors)) {
            return new WP_REST_Response(
                array('success' => false, 'message' => implode('; ', $errors)),
                200
            );
        }

        return self::get_cart();
    }

    // ======================
    // 优惠券管理
    // ======================

    /**
     * 获取可用优惠券列表
     *
     * @param WP_REST_Request $request 请求参数，可选包含 products 数组
     * @return WP_REST_Response 优惠券列表响应
     */
    public static function get_available_coupons($request)
    {
        self::ensure_woocommerce_session_and_cart();

        $product_items = $request->get_param('products');
        $has_products = is_array($product_items) && !empty($product_items);

        try {
            // 构造商品对象列表和数量映射
            $products = array();
            $quantities = array();
            if ($has_products) {
                foreach ($product_items as $item) {
                    $pid = isset($item['id']) ? absint($item['id']) : 0;
                    $qty = isset($item['quantity']) ? max(1, absint($item['quantity'])) : 1;
                    if (!$pid) {
                        continue;
                    }
                    $product = wc_get_product($pid);
                    if ($product) {
                        $products[$pid] = $product;
                        $quantities[$pid] = $qty;
                    }
                }
                $has_products = !empty($products);
            }

            // 查询所有已发布的优惠券
            $coupon_posts = get_posts(array(
                'posts_per_page' => 200,
                'orderby'        => 'date',
                'order'          => 'DESC',
                'post_type'      => 'shop_coupon',
                'post_status'    => 'publish',
            ));

            $now = current_time('timestamp');
            $user_id = get_current_user_id();
            $user_email = '';
            if ($user_id) {
                $user = get_userdata($user_id);
                $user_email = $user ? strtolower(trim($user->user_email)) : '';
            }

            // 计算传入商品的总价（用于最低/最高消费校验）
            $products_total = 0;
            if ($has_products) {
                foreach ($products as $pid => $product) {
                    $qty = isset($quantities[$pid]) ? $quantities[$pid] : 1;
                    $products_total += (float) wc_get_price_to_display($product) * $qty;
                }
            }

            $coupons = array();

            // 遍历筛选有效优惠券
            foreach ($coupon_posts as $post) {
                $coupon = new WC_Coupon($post->ID);

                // 过滤已过期
                $expiry = $coupon->get_date_expires();
                if ($expiry && $expiry->getTimestamp() < $now) {
                    continue;
                }

                // 过滤已达总使用上限
                $usage_limit = $coupon->get_usage_limit();
                if ($usage_limit > 0 && $coupon->get_usage_count() >= $usage_limit) {
                    continue;
                }

                // 过滤已达单用户使用上限
                $per_user_limit = $coupon->get_usage_limit_per_user();
                if ($per_user_limit > 0 && $user_id) {
                    $used_by = $coupon->get_used_by();
                    $user_usage = 0;
                    foreach ($used_by as $id) {
                        if ((string) $id === (string) $user_id || strtolower((string) $id) === $user_email) {
                            $user_usage++;
                        }
                    }
                    if ($user_usage >= $per_user_limit) {
                        continue;
                    }
                }

                // 检查商品/分类限制
                $has_product_restriction = !empty($coupon->get_product_ids())
                    || !empty($coupon->get_excluded_product_ids())
                    || !empty($coupon->get_product_categories())
                    || !empty($coupon->get_excluded_product_categories());

                if ($has_product_restriction) {
                    // 没传商品列表则跳过有商品限制的优惠券
                    if (!$has_products) {
                        continue;
                    }
                    // 检查是否有商品适用该优惠券
                    $applicable = false;
                    foreach ($products as $product) {
                        if ($coupon->is_valid_for_product($product)) {
                            $applicable = true;
                            break;
                        }
                    }
                    if (!$applicable) {
                        continue;
                    }
                }

                // 检查最低/最高消费金额限制，标记状态而非直接过滤
                $check_total = $has_products ? $products_total : 0;
                $min_amount = (float) $coupon->get_minimum_amount();
                $max_amount = (float) $coupon->get_maximum_amount();
                $coupon_status = 'available';

                if ($min_amount > 0 && $check_total < $min_amount) {
                    $coupon_status = 'not_available';
                }
                if ($max_amount > 0 && $check_total > $max_amount) {
                    continue;
                }

                $coupon_data = self::format_coupon_data($coupon, false);
                $coupon_data['status'] = $coupon_status;
                $coupon_data['minimum_cost'] = $min_amount > 0 ? wc_format_decimal($min_amount, wc_get_price_decimals()) : null;

                // 计算预估优惠金额（available 时为实际预估，not_available 时为达到门槛后的潜在优惠）
                if ($has_products) {
                    if ($coupon_status === 'available') {
                        $coupon_data['estimated_discount'] = self::calculate_coupon_discount($coupon, $products, $quantities);
                    } else {
                        // 按门槛金额模拟计算潜在优惠
                        $coupon_data['potential_discount'] = self::calculate_potential_discount($coupon, $min_amount);
                    }
                }

                $coupons[] = $coupon_data;
            }

            // 排序：available 优先，同 status 内按优惠金额降序
            usort($coupons, function ($a, $b) {
                $status_order = array('available' => 0, 'not_available' => 1);
                $sa = $status_order[$a['status']] ?? 1;
                $sb = $status_order[$b['status']] ?? 1;
                if ($sa !== $sb) {
                    return $sa <=> $sb;
                }
                $da = isset($a['estimated_discount']) ? (float) $a['estimated_discount'] : (isset($a['potential_discount']) ? (float) $a['potential_discount'] : 0);
                $db = isset($b['estimated_discount']) ? (float) $b['estimated_discount'] : (isset($b['potential_discount']) ? (float) $b['potential_discount'] : 0);
                return $db <=> $da;
            });

            return new WP_REST_Response(
                array(
                    'success' => true,
                    'data' => $coupons,
                ),
                200
            );
        } catch (Exception $e) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Failed to retrieve coupons: ' . $e->getMessage()),
                200
            );
        }
    }

    /**
     * 应用优惠券到购物车
     *
     * code 参数支持字符串（单个）或数组（批量）。
     *
     * @param WP_REST_Request $request 请求参数，包含 code 优惠券代码（string|array）
     * @return WP_REST_Response 应用结果响应，成功时返回优惠券信息和折扣金额
     */
    public static function apply_coupon($request)
    {
        self::ensure_woocommerce_session_and_cart();

        $code_param = $request->get_param('code');
        $codes = is_array($code_param) ? $code_param : array($code_param);
        $codes = array_map('sanitize_text_field', $codes);
        $codes = array_filter($codes);

        // 参数校验
        if (empty($codes)) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Coupon code is required.'),
                200
            );
        }

        $applied_coupons = array();
        $errors = array();

        foreach ($codes as $coupon_code) {
            // 检查优惠券是否存在
            $coupon = new WC_Coupon($coupon_code);
            if (!$coupon->get_id()) {
                $errors[] = sprintf('Invalid coupon code: %s', $coupon_code);
                continue;
            }

            // 检查是否已应用
            if (WC()->cart->has_discount($coupon_code)) {
                $errors[] = sprintf('Coupon has already been applied: %s', $coupon_code);
                continue;
            }

            // 应用优惠券（WC 内部完成验证：过期、使用次数、最低消费等）
            $applied = WC()->cart->apply_coupon($coupon_code);

            if (!$applied) {
                $error_notices = wc_get_notices('error');
                wc_clear_notices();
                $message = sprintf('Failed to apply coupon: %s', $coupon_code);
                if (!empty($error_notices)) {
                    $messages = array();
                    foreach ($error_notices as $notice) {
                        $messages[] = isset($notice['notice']) ? wp_strip_all_tags($notice['notice']) : wp_strip_all_tags($notice);
                    }
                    $message = implode(' ', $messages);
                }
                $errors[] = $message;
                continue;
            }

            $applied_coupons[] = self::format_coupon_data($coupon, true);
        }

        WC()->cart->calculate_totals();
        WC()->cart->set_session();

        $discount_total = WC()->cart->get_discount_total();
        $discount_tax = WC()->cart->get_discount_tax();

        if (!empty($errors) && empty($applied_coupons)) {
            return new WP_REST_Response(
                array('success' => false, 'message' => implode('; ', $errors)),
                200
            );
        }

        return new WP_REST_Response(
            array(
                'success' => true,
                'data' => array(
                    'applied_coupons' => $applied_coupons,
                    'errors' => $errors,
                    'discount_total' => wc_format_decimal($discount_total, wc_get_price_decimals()),
                    'discount_tax' => wc_format_decimal($discount_tax, wc_get_price_decimals()),
                    'discount_total_formatted' => wc_price($discount_total + $discount_tax),
                    'cart_total' => wc_price(WC()->cart->get_total('edit')),
                )
            ),
            200
        );
    }

    /**
     * 获取购物车中已应用的优惠券列表
     *
     * @return WP_REST_Response 已应用优惠券列表响应
     */
    public static function get_applied_coupons()
    {
        self::ensure_woocommerce_session_and_cart();

        try {
            WC()->cart->calculate_totals();

            $applied_codes = WC()->cart->get_applied_coupons();
            $decimals = wc_get_price_decimals();
            $coupons = array();

            foreach ($applied_codes as $code) {
                $coupon = new WC_Coupon($code);
                if (!$coupon->get_id()) {
                    continue;
                }
                $coupon_data = self::format_coupon_data($coupon, true);
                $coupon_data['discount_amount'] = wc_format_decimal(
                    WC()->cart->get_coupon_discount_amount($code),
                    $decimals
                );
                $coupons[] = $coupon_data;
            }

            $discount_total = WC()->cart->get_discount_total();
            $discount_tax = WC()->cart->get_discount_tax();

            return new WP_REST_Response(
                array(
                    'success' => true,
                    'data' => array(
                        'coupons' => $coupons,
                        'discount_total' => wc_format_decimal($discount_total, $decimals),
                        'discount_tax' => wc_format_decimal($discount_tax, $decimals),
                        'discount_total_formatted' => wc_price($discount_total + $discount_tax),
                        'cart_total' => wc_price(WC()->cart->get_total('edit')),
                    ),
                ),
                200
            );
        } catch (Exception $e) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Failed to retrieve applied coupons.'),
                200
            );
        }
    }

    /**
     * 移除购物车中已应用的优惠券
     *
     * code 参数支持字符串（单个）或数组（批量）。
     *
     * @param WP_REST_Request $request 请求参数，包含 code 优惠券代码（string|array）
     * @return WP_REST_Response 移除结果响应，成功时返回更新后的折扣金额
     */
    public static function remove_coupon($request)
    {
        self::ensure_woocommerce_session_and_cart();

        $code_param = $request->get_param('code');
        $codes = is_array($code_param) ? $code_param : array($code_param);
        $codes = array_map('sanitize_text_field', $codes);
        $codes = array_filter($codes);

        // 参数校验
        if (empty($codes)) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Coupon code is required.'),
                200
            );
        }

        $removed_coupons = array();
        $errors = array();

        foreach ($codes as $coupon_code) {
            if (!WC()->cart->has_discount($coupon_code)) {
                $errors[] = sprintf('Coupon is not applied to the cart: %s', $coupon_code);
                continue;
            }

            $removed = WC()->cart->remove_coupon($coupon_code);

            if (!$removed) {
                $errors[] = sprintf('Failed to remove coupon: %s', $coupon_code);
                continue;
            }

            $removed_coupons[] = $coupon_code;
        }

        WC()->cart->calculate_totals();
        WC()->cart->set_session();

        $discount_total = WC()->cart->get_discount_total();
        $discount_tax = WC()->cart->get_discount_tax();

        if (!empty($errors) && empty($removed_coupons)) {
            return new WP_REST_Response(
                array('success' => false, 'message' => implode('; ', $errors)),
                200
            );
        }

        return new WP_REST_Response(
            array(
                'success' => true,
                'data' => array(
                    'removed_coupons' => $removed_coupons,
                    'errors' => $errors,
                    'discount_total' => wc_format_decimal($discount_total, wc_get_price_decimals()),
                    'discount_tax' => wc_format_decimal($discount_tax, wc_get_price_decimals()),
                    'discount_total_formatted' => wc_price($discount_total + $discount_tax),
                    'cart_total' => wc_price(WC()->cart->get_total('edit')),
                ),
            ),
            200
        );
    }

    /**
     * 根据优惠券类型和商品列表计算预估优惠金额
     *
     * @param WC_Coupon $coupon 优惠券对象
     * @param array     $products 商品列表（pid => WC_Product）
     * @param array     $quantities 数量映射（pid => int）
     * @return float 预估优惠金额
     */
    private static function calculate_coupon_discount($coupon, $products, $quantities)
    {
        $discount_type = $coupon->get_discount_type();
        $amount = (float) $coupon->get_amount();
        $discount = 0.0;

        // 获取优惠券限制的商品 ID（空数组表示不限制）
        $coupon_product_ids = $coupon->get_product_ids();
        $has_product_restriction = !empty($coupon_product_ids);

        switch ($discount_type) {
            case 'percent':
                // 百分比折扣：对每个适用商品按比例计算
                foreach ($products as $pid => $product) {
                    if ($has_product_restriction && !in_array($pid, $coupon_product_ids)) {
                        continue;
                    }
                    if (!$coupon->is_valid_for_product($product)) {
                        continue;
                    }
                    $qty = isset($quantities[$pid]) ? $quantities[$pid] : 1;
                    $price = (float) wc_get_price_to_display($product);
                    $discount += $price * $qty * ($amount / 100);
                }
                // 百分比优惠券可能有最大折扣上限
                $max_discount = $coupon->get_maximum_amount();
                if ($max_discount > 0 && $discount > $max_discount) {
                    $discount = (float) $max_discount;
                }
                break;

            case 'fixed_product':
                // 每件商品固定减免
                $limit = (int) $coupon->get_limit_usage_to_x_items(); // 0 表示不限制
                $applied_items = 0;
                foreach ($products as $pid => $product) {
                    if ($limit > 0 && $applied_items >= $limit) {
                        break;
                    }
                    if ($has_product_restriction && !in_array($pid, $coupon_product_ids)) {
                        continue;
                    }
                    if (!$coupon->is_valid_for_product($product)) {
                        continue;
                    }
                    $qty = isset($quantities[$pid]) ? $quantities[$pid] : 1;
                    if ($limit > 0) {
                        $qty = min($qty, $limit - $applied_items);
                    }
                    $price = (float) wc_get_price_to_display($product);
                    // 单件优惠不能超过商品价格
                    $per_item_discount = min($amount, $price);
                    $discount += $per_item_discount * $qty;
                    $applied_items += $qty;
                }
                break;

            case 'fixed_cart':
                // 整个购物车固定减免
                $total = 0;
                foreach ($products as $pid => $product) {
                    $qty = isset($quantities[$pid]) ? $quantities[$pid] : 1;
                    $total += (float) wc_get_price_to_display($product) * $qty;
                }
                // 折扣不能超过商品总价
                $discount = min($amount, $total);
                break;

            default:
                // 其他类型不计算
                break;
        }

        return round($discount, wc_get_price_decimals());
    }

    /**
     * 计算优惠券达到门槛后的潜在优惠金额
     *
     * @param WC_Coupon $coupon 优惠券对象
     * @param float     $minimum_amount 最低消费门槛
     * @return float 潜在优惠金额
     */
    private static function calculate_potential_discount($coupon, $minimum_amount)
    {
        $discount_type = $coupon->get_discount_type();
        $amount = (float) $coupon->get_amount();
        $discount = 0.0;

        switch ($discount_type) {
            case 'percent':
                $discount = $minimum_amount * ($amount / 100);
                $max_discount = (float) $coupon->get_maximum_amount();
                if ($max_discount > 0 && $discount > $max_discount) {
                    $discount = $max_discount;
                }
                break;

            case 'fixed_cart':
                $discount = min($amount, $minimum_amount);
                break;

            case 'fixed_product':
                $discount = $amount;
                break;

            default:
                break;
        }

        return round($discount, wc_get_price_decimals());
    }

    /**
     * 格式化优惠券数据
     *
     * @param WC_Coupon $coupon 优惠券对象
     * @param bool      $is_applied 是否已应用到购物车
     * @return array 格式化后的优惠券数据，包含 code、id、amount、discount_type、is_applied、description
     */
    private static function format_coupon_data($coupon, $is_applied = false)
    {
        $discount_type = $coupon->get_discount_type();
        $amount = $coupon->get_amount();

        return array(
            'code' => $coupon->get_code(),
            'id' => $coupon->get_id(),
            'amount' => wc_format_decimal($amount, wc_get_price_decimals()),
            'discount_type' => $discount_type,
            'is_applied' => $is_applied,
            'description' => $coupon->get_description(),
        );
    }

    /**
     * 获取地址字段定义及当前用户地址值
     *
     * @return WP_REST_Response 地址字段响应
     */
    public static function get_address_fields()
    {
        self::ensure_woocommerce_session_and_cart();

        if (!WC()->customer) {
            WC()->customer = new WC_Customer(get_current_user_id(), true);
        }

        try {
            $country = '';

            $raw_billing_fields = WC()->countries->get_address_fields($country, 'billing_');
            $raw_shipping_fields = WC()->countries->get_address_fields($country, 'shipping_');

            // 处理账单地址字段
            $billing_fields = array();
            $billing_values = array();
            foreach ($raw_billing_fields as $key => $field) {
                $fixed_key = preg_replace('/^billing([a-z])/', 'billing_$1', $key);
                $fixed_key = preg_replace('/^shipping([a-z])/', 'shipping_$1', $fixed_key);

                $safe_field = array(
                    'type' => $field['type'] ?? 'text',
                    'label' => $field['label'] ?? '',
                    'placeholder' => $field['placeholder'] ?? '',
                    'required' => !empty($field['required']),
                    'class' => $field['class'] ?? array(),
                    'options' => $field['options'] ?? array(),
                    'default' => $field['default'] ?? '',
                );

                $billing_fields[$fixed_key] = $safe_field;
                $billing_values[$fixed_key] = WC()->customer ? WC()->customer->{"get_{$fixed_key}"}() : '';
            }

            // 处理配送地址字段
            $shipping_fields = array();
            $shipping_values = array();
            foreach ($raw_shipping_fields as $key => $field) {
                $fixed_key = preg_replace('/^billing([a-z])/', 'billing_$1', $key);
                $fixed_key = preg_replace('/^shipping([a-z])/', 'shipping_$1', $fixed_key);

                $safe_field = array(
                    'type' => $field['type'] ?? 'text',
                    'label' => $field['label'] ?? '',
                    'placeholder' => $field['placeholder'] ?? '',
                    'required' => !empty($field['required']),
                    'class' => $field['class'] ?? array(),
                    'options' => $field['options'] ?? array(),
                    'default' => $field['default'] ?? '',
                );

                $shipping_fields[$fixed_key] = $safe_field;
                $shipping_values[$fixed_key] = WC()->customer ? WC()->customer->{"get_{$fixed_key}"}() : '';
            }

            return new WP_REST_Response(
                array(
                    'success' => true,
                    'data' => array(
                        'billing' => array(
                            'fields' => $billing_fields,
                            'values' => $billing_values,
                        ),
                        'shipping' => array(
                            'fields' => $shipping_fields,
                            'values' => $shipping_values,
                        ),
                    )
                ),
                200
            );
        } catch (Exception $e) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Could not load address fields.'),
                200
            );
        }
    }

    /**
     * 保存用户地址信息
     *
     * @param WP_REST_Request $request 请求参数，包含 billing 和 shipping 地址数据
     * @return WP_REST_Response 保存结果响应
     */
    public static function save_address($request)
    {
        self::ensure_woocommerce_session_and_cart();

        $data = $request->get_params();

        $billing_data = isset($data['billing']) && is_array($data['billing']) ? $data['billing'] : array();
        $shipping_data = isset($data['shipping']) && is_array($data['shipping']) ? $data['shipping'] : array();

        // 保存账单地址
        foreach ($billing_data as $key => $value) {
            if (!is_callable(array(WC()->customer, "set_billing_{$key}"))) {
                continue;
            }
            WC()->customer->{"set_billing_{$key}"}(sanitize_text_field($value));
        }

        // 保存配送地址（仅当需要配送时）
        if (WC()->cart->needs_shipping() && !empty($shipping_data)) {
            foreach ($shipping_data as $key => $value) {
                if (!is_callable(array(WC()->customer, "set_shipping_{$key}"))) {
                    continue;
                }
                WC()->customer->{"set_shipping_{$key}"}(sanitize_text_field($value));
            }
        }

        WC()->customer->save();

        return new WP_REST_Response(
            array('success' => true),
            200
        );
    }

    /**
     * 获取国家列表
     *
     * @return WP_REST_Response 国家列表响应
     */
    public static function get_countries()
    {
        try {
            $countries = WC()->countries->get_countries();

            $formatted_countries = array();
            foreach ($countries as $code => $name) {
                $formatted_countries[] = array(
                    'code' => $code,
                    'name' => $name,
                );
            }

            return new WP_REST_Response(
                array('success' => true, 'data' => $formatted_countries),
                200
            );
        } catch (Exception $e) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Could not fetch countries.'),
                200
            );
        }
    }

    /**
     * 获取指定国家的省/州列表
     *
     * @param WP_REST_Request $request 请求参数，包含 country 国家代码（必填）
     * @return WP_REST_Response 省/州列表响应
     */
    public static function get_states($request)
    {
        $country = $request->get_param('country');
        $country = is_string($country) ? sanitize_text_field($country) : '';

        // 参数校验
        if ('' === $country) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Country code is required.'),
                200
            );
        }

        try {
            $states = WC()->countries->get_states($country);

            if (!$states || !is_array($states)) {
                return new WP_REST_Response(
                    array('success' => true, 'data' => array()),
                    200
                );
            }

            $formatted_states = array();
            foreach ($states as $code => $name) {
                $formatted_states[] = array(
                    'code' => $code,
                    'name' => $name,
                );
            }

            return new WP_REST_Response(
                array('success' => true, 'data' => $formatted_states),
                200
            );
        } catch (Exception $e) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Could not fetch state'),
                200
            );
        }
    }

    // ======================
    // 配送管理
    // ======================

    /**
     * 计算当前购物车的配送方式和费用
     *
     * @return WP_REST_Response 配送方式列表响应
     */
    public static function calculate_shipping()
    {
        self::ensure_woocommerce_session_and_cart();

        try {
            WC()->cart->calculate_shipping();
            WC()->cart->calculate_totals();

            $packages = WC()->shipping->get_packages();
            $methods = array();

            foreach ($packages as $package) {
                if (empty($package['rates'])) {
                    continue;
                }
                foreach ($package['rates'] as $rate) {
                    $methods[] = array(
                        'id' => $rate->id,
                        'label' => $rate->label,
                        'cost' => (float) $rate->cost,
                        'cost_formatted' => wc_price($rate->cost),
                    );
                }
            }

            return new WP_REST_Response(
                array('success' => true, 'data' => $methods),
                200
            );
        } catch (Exception $e) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Shipping calculation failed.'),
                200
            );
        }
    }

    /**
     * 根据地址获取可用配送方式
     *
     * @param WP_REST_Request $request 请求参数，包含 address 地址对象
     * @return WP_REST_Response 配送方式列表响应
     */
    public static function get_shipping_methods(WP_REST_Request $request)
    {
        if (!function_exists('WC')) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'WooCommerce not active'),
                200
            );
        }

        // 确保 session/cart/customer 已初始化
        if (null === WC()->session) {
            WC()->initialize_session();
        }
        if (null === WC()->customer) {
            WC()->initialize_customer();
        }
        if (null === WC()->cart) {
            WC()->initialize_cart();
        }

        $params = $request->get_json_params();
        $address = isset($params['address']) && is_array($params['address']) ? $params['address'] : array();

        // 解析地址参数
        $country = isset($address['country']) ? wc_strtoupper(wc_clean($address['country'])) : '';
        $state = isset($address['state']) ? wc_strtoupper(wc_clean($address['state'])) : '';
        $postcode = isset($address['postcode']) ? wc_clean($address['postcode']) : '';
        $city = isset($address['city']) ? wc_clean($address['city']) : '';
        $address_1 = isset($address['address_1']) ? wc_clean($address['address_1']) : '';
        $address_2 = isset($address['address_2']) ? wc_clean($address['address_2']) : '';

        // 国家代码必填
        if ('' === $country) {
            return new WP_REST_Response(array('message' => 'country is required'), 400);
        }

        // 全虚拟购物车不需要配送
        if (!WC()->cart->needs_shipping()) {
            return new WP_REST_Response(
                array(
                    'success' => true,
                    'data' => array(
                        'has_shipping_methods' => false,
                        'needs_shipping' => false,
                        'message' => '',
                        'packages' => array(),
                    )
                ),
                200
            );
        }

        // 写入配送地址到 customer
        WC()->customer->set_shipping_country($country);
        WC()->customer->set_shipping_state($state);
        WC()->customer->set_shipping_postcode($postcode);
        WC()->customer->set_shipping_city($city);
        WC()->customer->set_shipping_address($address_1);
        WC()->customer->set_shipping_address_2($address_2);

        // 同时写入账单地址
        WC()->customer->set_billing_country($country);
        WC()->customer->set_billing_state($state);
        WC()->customer->set_billing_postcode($postcode);
        WC()->customer->set_billing_city($city);
        WC()->customer->set_billing_address($address_1);
        WC()->customer->set_billing_address_2($address_2);

        WC()->customer->save();

        // 计算运费
        WC()->cart->calculate_totals();

        $packages = WC()->shipping()->get_packages();
        // 如果 packages 为空，尝试重新计算
        if (empty($packages)) {
            WC()->shipping()->calculate_shipping(WC()->cart->get_shipping_packages());
            $packages = WC()->shipping()->get_packages();
        }

        $result = array();

        // 遍历包裹获取配送方式
        foreach ($packages as $package_index => $package) {
            $rates = isset($package['rates']) ? $package['rates'] : array();

            $methods = array();
            foreach ($rates as $rate_id => $rate) {
                /** @var WC_Shipping_Rate $rate */
                $methods[] = array(
                    'id' => $rate->get_id(),          // 如 flat_rate:3
                    'method_id' => $rate->get_method_id(),   // 如 flat_rate
                    'instance_id' => $rate->get_instance_id(),
                    'label' => $rate->get_label(),
                    'cost' => wc_format_decimal($rate->get_cost(), wc_get_price_decimals()),
                    'taxes' => array_values($rate->get_taxes()),
                    'total' => wc_format_decimal((float) $rate->get_cost() + array_sum($rate->get_taxes()), wc_get_price_decimals()),
                    'meta_data' => $rate->get_meta_data(),
                );
            }

            $result[] = array(
                'package_index' => $package_index,
                'destination' => isset($package['destination']) ? $package['destination'] : array(),
                'shipping_methods' => $methods,
            );
        }

        // 检查是否有可用配送方式
        $has_methods = false;
        if (!empty($result)) {
            foreach ($result as $pkg) {
                if (!empty($pkg['shipping_methods'])) {
                    $has_methods = true;
                    break;
                }
            }
        }

        $message = '';
        // 无可用配送方式时构造提示信息
        if (!$has_methods) {
            $destination = array(
                'country' => $country,
                'state' => $state,
                'postcode' => $postcode,
                'city' => $city,
                'address' => $address_1,
                'address_2' => $address_2,
            );

            $result = array(
                array(
                    'package_index' => 0,
                    'destination' => $destination,
                    'shipping_methods' => array(),
                ),
            );

            $formatted_destination = WC()->countries->get_formatted_address(array(
                'country' => $country,
                'state' => $state,
                'postcode' => $postcode,
                'city' => $city,
                'address_1' => $address_1,
                'address_2' => $address_2,
            ));
            $message = sprintf(
                'No shipping options were found for %s.',
                '<strong>' . esc_html(wp_strip_all_tags($formatted_destination)) . '</strong>'
            );
            $message .= ' Enter a different address.';
        }

        return new WP_REST_Response(
            array(
                'success' => true,
                'data' => array(
                    'address_used' => array(
                        'country' => $country,
                        'state' => $state,
                        'postcode' => $postcode,
                        'city' => $city,
                    ),
                    'has_shipping_methods' => $has_methods,
                    'message' => $message,
                    'packages' => $result,
                )
            ),
            200
        );
    }

    /**
     * 获取订单信息
     *
     * 支持两种模式：
     * 1. 通过 order_id + order_key 查询指定订单（无需登录）
     * 2. 登录用户返回近 1 个月的订单列表（最多 50 条）
     *
     * @param WP_REST_Request $request 请求参数
     * @return WP_REST_Response 订单数据响应
     */
    public static function get_orders(WP_REST_Request $request)
    {
        if (!function_exists('wc_get_order')) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'WooCommerce not active'),
                200
            );
        }

        $order_id = absint($request->get_param('order_id'));
        $order_key = (string) $request->get_param('order_key');

        // 模式 A：通过 order_id + order_key 查询指定订单
        if ($order_id && $order_key !== '') {
            $order = wc_get_order($order_id);
            if (!$order) {
                return new WP_REST_Response(
                    array('success' => false, 'message' => 'Order not found'),
                    200
                );
            }
            // 校验 order_key
            if (!hash_equals((string) $order->get_order_key(), $order_key)) {
                return new WP_REST_Response(
                    array('success' => false, 'message' => 'Invalid order key'),
                    200
                );
            }
            return new WP_REST_Response(
                array('success' => true, 'data' => self::format_order_detail($order)),
                200
            );
        }

        // 模式 B：登录用户返回近 1 个月的订单列表
        if (!is_user_logged_in()) {
            return new WP_REST_Response(
                array('success' => false, 'message' => "order_id is required or user must be logged in"),
                200
            );
        }

        $user_id = get_current_user_id();
        $after = (new DateTime('now', wp_timezone()))->modify('-1 month');
        $query = new WC_Order_Query(array(
            'customer_id' => $user_id,
            'limit' => 50,
            'orderby' => 'date',
            'order' => 'DESC',
            'date_created' => '>' . $after->format('Y-m-d H:i:s'),
            'return' => 'ids',
        ));
        $ids = $query->get_orders();
        $list = array();
        foreach ($ids as $id) {
            $o = wc_get_order($id);
            if (!$o) {
                continue;
            }
            $list[] = self::format_order_detail($o);
        }

        return new WP_REST_Response(
            array('success' => true, 'data' => $list),
            200
        );
    }

    /**
     * 格式化订单详情数据
     *
     * @param WC_Order $order 订单对象
     * @return array 格式化后的订单数据
     */
    private static function format_order_detail(WC_Order $order)
    {
        // 配送地址
        $shipping = array(
            'country' => (string) $order->get_shipping_country(),
            'city' => (string) $order->get_shipping_city(),
            'address_1' => (string) $order->get_shipping_address_1(),
            'postcode' => (string) $order->get_shipping_postcode(),
            'last_name' => (string) $order->get_shipping_last_name(),
            'state' => (string) $order->get_shipping_state(),
            'first_name' => (string) $order->get_shipping_first_name(),
        );

        // 商品列表
        $goods = array();
        foreach ($order->get_items('line_item') as $item) {
            if (!$item instanceof WC_Order_Item_Product) {
                continue;
            }
            $product = $item->get_product();
            if (!$product) {
                continue;
            }
            $product_id = $product->get_id();
            $image_id = $product->get_image_id();
            $image_url = $image_id ? wp_get_attachment_image_url($image_id, 'full') : '';
            $qty = max(1, (int) $item->get_quantity());
            $line_total = (float) $item->get_total(); // 不含税
            $unit_price = $line_total / $qty;
            $goods[] = array(
                'id' => $product_id,
                'name' => (string) $item->get_name(),
                'image' => (string) $image_url,
                'price' => wc_format_decimal($unit_price, 2),
                'quantity' => $qty,
                'regular_price' => wc_format_decimal((float) $product->get_regular_price(), 2),
                'sale_price' => wc_format_decimal((float) $product->get_sale_price(), 2),
                'short_description' => (string) wp_strip_all_tags($product->get_short_description()),
                'in_stock' => (bool) $product->is_in_stock(),
                'permalink' => (string) get_permalink($product_id),
            );
        }

        $discount_total = (float) $order->get_discount_total() + (float) $order->get_discount_tax();
        $shipping_total = (float) $order->get_shipping_total();
        $created = $order->get_date_created();
        $updated = $order->get_date_modified();

        return array(
            'total' => wc_format_decimal((float) $order->get_total(), 2),
            'shippingAddress' => $shipping,
            'orderId' => $order->get_id(),
            'orderKey' => (string) $order->get_order_key(),
            'buyerEmail' => (string) $order->get_billing_email(),
            'gmtUpdate' => $updated ? $updated->date('Y/m/d H:i') : null,
            'goods' => $goods,
            'discount' => wc_format_decimal($discount_total, 2),
            'shipping_total' => wc_format_decimal($shipping_total, 2),
            'currency' => (string) $order->get_currency(),
            'gmtCreate' => $created ? $created->date('Y/m/d H:i') : null,
            'status' => (string) $order->get_status(),
        );
    }

    // ======================
    // 支付管理
    // ======================

    /**
     * 获取可用支付方式列表
     *
     * @return WP_REST_Response 支付方式列表响应
     */
    public static function get_payment_methods()
    {
        self::ensure_woocommerce_session_and_cart();

        try {
            $available_gateways = WC()->payment_gateways->get_available_payment_gateways();
            $methods = array();

            foreach ($available_gateways as $gateway) {
                // 获取支付表单 HTML
                ob_start();
                $gateway->payment_fields();
                $payment_html = ob_get_clean();
                $payment_html = preg_replace('/\s+/', ' ', trim($payment_html));

                $methods[] = array(
                    'id' => $gateway->id,
                    'title' => $gateway->title,
                    'description' => $gateway->description ?? '',
                    'tag' => $payment_html,
                );
            }

            return new WP_REST_Response(
                array('success' => true, 'data' => $methods),
                200
            );
        } catch (Exception $e) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Could not load payment methods.'),
                200
            );
        }
    }

    /**
     * 处理结账流程
     *
     * @param WP_REST_Request $request 请求参数
     * @return WP_REST_Response 结账结果响应，成功时返回订单信息和支付跳转 URL
     */
    public static function process_checkout(WP_REST_Request $request)
    {
        self::ensure_woocommerce_session_and_cart();

        // 1. 解析入参
        $params = $request->get_json_params();
        $address_data = isset($params['addressData']) && is_array($params['addressData']) ? $params['addressData'] : array();
        $billing_data = isset($address_data['billing']) && is_array($address_data['billing']) ? $address_data['billing'] : array();
        $shipping_data = isset($address_data['shipping']) && is_array($address_data['shipping']) ? $address_data['shipping'] : array();

        // 2. 配送方式（虚拟商品无需配送，否则必填）
        $method = isset($address_data['shipping_method']) ? sanitize_text_field($address_data['shipping_method']) : '';
        if ('' === $method && WC()->cart->needs_shipping()) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Shipping method is required.'),
                200
            );
        }
        if ('' !== $method) {
            WC()->session->set('chosen_shipping_methods', array($method));
        }

        // 3. 支付网关（默认 antom）
        $gateway_id = sanitize_text_field((string) $request->get_param('payment_method_gateWay'));
        if ('' === $gateway_id) {
            $gateway_id = 'antom';
        }

        // 4. 购物车校验
        if (WC()->cart->is_empty()) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Your cart is empty.'),
                200
            );
        }

        // 5. 写入地址到 WC Customer，触发运费重算
        if (WC()->customer) {
            foreach ($billing_data as $key => $value) {
                $setter = "set_billing_{$key}";
                if (is_callable(array(WC()->customer, $setter))) {
                    WC()->customer->{$setter}(sanitize_text_field($value));
                }
            }
            foreach ($shipping_data as $key => $value) {
                $setter = "set_shipping_{$key}";
                if (is_callable(array(WC()->customer, $setter))) {
                    WC()->customer->{$setter}(sanitize_text_field($value));
                }
            }
            WC()->customer->save();
        }

        // 确保 shipping packages 已生成
        WC()->cart->calculate_shipping();
        WC()->cart->calculate_totals();

        // 6. 校验支付网关是否可用
        WC()->payment_gateways();
        $gateways = WC()->payment_gateways->payment_gateways();
        if (!isset($gateways[$gateway_id])) {
            return new WP_REST_Response(
                array('success' => false, 'message' => 'Selected payment gateway is not active.'),
                200
            );
        }

        // 7. 为 Stripe 写入 $_POST（Stripe 插件内部读取）
        if ('stripe' === $gateway_id) {
            $stripe_payment_method_id = sanitize_text_field((string) $request->get_param('payment_method_id'));
            $stripe_payment_method_type = sanitize_text_field((string) $request->get_param('payment_method_type'));
            if (empty($stripe_payment_method_id) && empty($stripe_payment_method_type)) {
                return new WP_REST_Response(
                    array('success' => false, 'message' => 'Missing Stripe payment_method_id or payment_method_type.'),
                    200
                );
            }
            $_POST['payment_method'] = $stripe_payment_method_type;
            $_POST['wc-stripe-payment-method'] = $stripe_payment_method_id;
            $gateway_is_deferred_intent = $request->get_param('stripe_is_deferred_intent');
            $_POST['wc-stripe-is-deferred-intent'] = $gateway_is_deferred_intent ? sanitize_text_field($gateway_is_deferred_intent) : '1';
        } else {
            $_POST['payment_method'] = $gateway_id;
        }

        // 8. 创建订单
        $checkout_data = array('payment_method' => $gateway_id);
        foreach ($billing_data as $key => $value) {
            $checkout_data["billing_{$key}"] = sanitize_text_field($value);
        }
        foreach ($shipping_data as $key => $value) {
            $checkout_data["shipping_{$key}"] = sanitize_text_field($value);
        }
        if (!empty($shipping_data)) {
            $checkout_data['ship_to_different_address'] = 1;
        }

        try {
            $checkout = WC()->checkout();
            $order_id = $checkout->create_order($checkout_data);

            if (is_wp_error($order_id)) {
                return new WP_REST_Response(
                    array('success' => false, 'message' => $order_id->get_error_message()),
                    200
                );
            }
            if (!$order_id) {
                return new WP_REST_Response(
                    array('success' => false, 'message' => 'Unable to create order.'),
                    200
                );
            }

            // 设置支付方式
            $order = wc_get_order($order_id);
            $order->set_payment_method($gateway_id);
            $order->save();
        } catch (Exception $e) {
            return new WP_REST_Response(
                array('success' => false, 'message' => $e->getMessage()),
                200
            );
        }

        // 9. 调用网关 process_payment()
        $gateway = $gateways[$gateway_id];
        $result = $gateway->process_payment($order_id);

        // 10. 处理支付结果
        if (is_array($result) && isset($result['result']) && 'success' === $result['result']) {
            $order = wc_get_order($order_id);
            WC()->cart->empty_cart();
            return new WP_REST_Response(
                array(
                    'success' => true,
                    'data' => array(
                        'success' => true,
                        'redirect' => isset($result['redirect']) ? $result['redirect'] : '',
                        'order_id' => $order->get_id(),
                        'order_key' => $order->get_order_key(),
                        'is_paid' => $order->is_paid(),
                        'payment_method' => $order->get_payment_method(),
                        'payment_method_title' => $order->get_payment_method_title(),
                    )
                ),
                200
            );
        }

        // 支付失败：标记订单为 failed
        $failed_order = wc_get_order($order_id);
        if ($failed_order) {
            $failed_order->update_status('failed', 'Payment failed via API.');
        }

        $msg = isset($result['messages']) ? wp_strip_all_tags($result['messages']) : 'Payment failed.';
        return new WP_REST_Response(
            array('success' => false, 'message' => $msg),
            200
        );
    }
}