实操指南：构建售后与退货处理接口的3个周全方法

引言：售后接口在电商系统中的重要性

在当今竞争激烈的电商环境中，完善的售后与退货处理系统不仅是提升客户满意度的关键，更是企业运营效率的重要保障。根据Statista的数据显示，超过60%的在线购物者在购买前会查看退货政策，而高效的退货处理可以将客户保留率提高30%以上。

对于使用WordPress构建电商网站的开发者和企业来说，构建一个稳定、高效的售后与退货处理接口尤为重要。WordPress作为全球最流行的内容管理系统，配合WooCommerce等电商插件，为开发者提供了强大的基础框架。然而，标准解决方案往往无法满足企业的个性化需求，这就需要我们深入代码层面，构建定制化的售后接口。

本文将基于WordPress开源系统，为行业新人和程序员提供三种周全的售后与退货处理接口构建方法，从基础到高级，逐步深入。

方法一：基于WooCommerce原生功能的扩展开发

1.1 WooCommerce售后系统基础架构分析

WooCommerce作为WordPress最流行的电商插件，已经内置了基本的订单管理和退款功能。要构建售后接口，首先需要理解其核心数据结构：

// WooCommerce订单退款相关的主要数据表
// wp_woocommerce_order_items - 订单项目
// wp_woocommerce_order_itemmeta - 订单项目元数据
// wp_posts (post_type = 'shop_order') - 订单主数据
// wp_postmeta - 订单元数据
// wp_comments (comment_type = 'order_note') - 订单备注/历史

// 退款创建的基本流程
function create_woocommerce_refund($order_id, $amount, $reason) {
    $order = wc_get_order($order_id);
    
    // 创建退款对象
    $refund = wc_create_refund(array(
        'amount'         => $amount,
        'reason'         => $reason,
        'order_id'       => $order_id,
        'refund_payment' => true, // 是否退款到支付方式
        'restock_items'  => true  // 是否恢复库存
    ));
    
    return $refund;
}

1.2 创建基础的售后请求处理接口

基于WooCommerce原生功能，我们可以构建一个基础的售后请求处理接口：

/**
 * 售后请求处理类
 */
class Basic_After_Sales_Handler {
    
    private $request_types = array('refund', 'return', 'exchange', 'repair');
    
    /**
     * 初始化售后系统
     */
    public function init() {
        // 注册售后请求自定义帖子类型
        add_action('init', array($this, 'register_after_sales_post_type'));
        
        // 添加REST API端点
        add_action('rest_api_init', array($this, 'register_rest_endpoints'));
        
        // 添加管理界面
        add_action('admin_menu', array($this, 'add_admin_menu'));
    }
    
    /**
     * 注册售后请求自定义帖子类型
     */
    public function register_after_sales_post_type() {
        $labels = array(
            'name'               => '售后请求',
            'singular_name'      => '售后请求',
            'menu_name'          => '售后管理',
            'add_new'            => '添加请求',
            'add_new_item'       => '添加新售后请求',
            'edit_item'          => '编辑售后请求',
            'new_item'           => '新售后请求',
            'view_item'          => '查看售后请求',
            'search_items'       => '搜索售后请求',
            'not_found'          => '未找到售后请求',
            'not_found_in_trash' => '回收站中无售后请求'
        );
        
        $args = array(
            'labels'             => $labels,
            'public'             => false,
            'publicly_queryable' => false,
            'show_ui'            => true,
            'show_in_menu'       => true,
            'query_var'          => true,
            'rewrite'            => array('slug' => 'after-sales'),
            'capability_type'    => 'post',
            'has_archive'        => false,
            'hierarchical'       => false,
            'menu_position'      => 56,
            'menu_icon'          => 'dashicons-undo',
            'supports'           => array('title', 'editor', 'author', 'custom-fields'),
            'show_in_rest'       => true // 启用REST API支持
        );
        
        register_post_type('after_sales_request', $args);
        
        // 注册售后状态分类
        register_taxonomy(
            'after_sales_status',
            'after_sales_request',
            array(
                'label' => '售后状态',
                'rewrite' => array('slug' => 'after-sales-status'),
                'hierarchical' => true,
                'show_in_rest' => true
            )
        );
    }
    
    /**
     * 注册REST API端点
     */
    public function register_rest_endpoints() {
        // 创建售后请求端点
        register_rest_route('after-sales/v1', '/request', array(
            'methods' => 'POST',
            'callback' => array($this, 'handle_after_sales_request'),
            'permission_callback' => array($this, 'check_request_permission'),
            'args' => array(
                'order_id' => array(
                    'required' => true,
                    'validate_callback' => function($param) {
                        return is_numeric($param) && $param > 0;
                    }
                ),
                'request_type' => array(
                    'required' => true,
                    'validate_callback' => function($param) {
                        $allowed_types = array('refund', 'return', 'exchange', 'repair');
                        return in_array($param, $allowed_types);
                    }
                ),
                'reason' => array(
                    'required' => true,
                    'sanitize_callback' => 'sanitize_text_field'
                ),
                'items' => array(
                    'required' => false,
                    'validate_callback' => function($param) {
                        return is_array($param);
                    }
                )
            )
        ));
        
        // 获取售后请求状态端点
        register_rest_route('after-sales/v1', '/status/(?P<id>d+)', array(
            'methods' => 'GET',
            'callback' => array($this, 'get_request_status'),
            'permission_callback' => function() {
                return current_user_can('read');
            }
        ));
    }
    
    /**
     * 处理售后请求
     */
    public function handle_after_sales_request($request) {
        $parameters = $request->get_params();
        
        // 验证订单是否存在且属于当前用户
        $order = wc_get_order($parameters['order_id']);
        if (!$order) {
            return new WP_Error('invalid_order', '订单不存在', array('status' => 404));
        }
        
        // 检查用户权限
        $user_id = get_current_user_id();
        if ($order->get_customer_id() !== $user_id && !current_user_can('manage_woocommerce')) {
            return new WP_Error('permission_denied', '无权访问此订单', array('status' => 403));
        }
        
        // 创建售后请求记录
        $request_id = wp_insert_post(array(
            'post_title'   => sprintf('售后请求 - 订单 #%s', $parameters['order_id']),
            'post_content' => $parameters['reason'],
            'post_status'  => 'publish',
            'post_type'    => 'after_sales_request',
            'post_author'  => $user_id,
            'meta_input'   => array(
                '_order_id'     => $parameters['order_id'],
                '_request_type' => $parameters['request_type'],
                '_status'       => 'pending',
                '_request_date' => current_time('mysql')
            )
        ));
        
        // 添加请求物品信息
        if (!empty($parameters['items']) && is_array($parameters['items'])) {
            update_post_meta($request_id, '_request_items', $parameters['items']);
        }
        
        // 发送通知邮件
        $this->send_notification_email($order, $request_id, $parameters);
        
        // 记录操作日志
        $order->add_order_note(sprintf('客户提交了%s请求，原因：%s', 
            $this->get_request_type_name($parameters['request_type']), 
            $parameters['reason']
        ));
        
        return array(
            'success' => true,
            'request_id' => $request_id,
            'message' => '售后请求已提交，我们将在24小时内处理'
        );
    }
    
    /**
     * 发送通知邮件
     */
    private function send_notification_email($order, $request_id, $parameters) {
        $to = get_option('admin_email');
        $subject = sprintf('新的售后请求 #%s - 订单 #%s', $request_id, $order->get_id());
        
        $message = sprintf(
            "收到新的售后请求：nn请求ID：%sn订单号：%sn请求类型：%sn原因：%sn客户：%snn请登录后台查看详情。",
            $request_id,
            $order->get_id(),
            $this->get_request_type_name($parameters['request_type']),
            $parameters['reason'],
            $order->get_billing_first_name() . ' ' . $order->get_billing_last_name()
        );
        
        wp_mail($to, $subject, $message);
    }
}

1.3 实现前端用户界面

为了让用户能够方便地提交售后请求，我们需要创建一个前端界面：

/**
 * 前端售后请求表单
 */
function after_sales_request_form($order_id = null) {
    // 如果未提供订单ID，尝试从URL参数获取
    if (!$order_id && isset($_GET['order_id'])) {
        $order_id = intval($_GET['order_id']);
    }
    
    // 验证订单
    if (!$order_id) {
        return '<div class="alert alert-danger">请提供有效的订单号</div>';
    }
    
    $order = wc_get_order($order_id);
    if (!$order) {
        return '<div class="alert alert-danger">订单不存在</div>';
    }
    
    // 检查当前用户是否有权访问此订单
    $user_id = get_current_user_id();
    if ($order->get_customer_id() !== $user_id && !current_user_can('manage_woocommerce')) {
        return '<div class="alert alert-danger">您无权访问此订单</div>';
    }
    
    // 检查订单是否在可售后时间内（例如30天内）
    $order_date = $order->get_date_created();
    $current_date = new DateTime();
    $order_age = $current_date->diff($order_date)->days;
    
    if ($order_age > 30) {
        return '<div class="alert alert-warning">此订单已超过30天售后期限</div>';
    }
    
    ob_start();
    ?>
    <div class="after-sales-request-form">
        <h3>提交售后请求 - 订单 #<?php echo $order->get_id(); ?></h3>
        
        <form id="after-sales-request-form" method="post">
            <input type="hidden" name="order_id" value="<?php echo $order->get_id(); ?>">
            
            <div class="form-group">
                <label for="request_type">请求类型 *</label>
                <select name="request_type" id="request_type" required class="form-control">
                    <option value="">请选择请求类型</option>
                    <option value="refund">仅退款</option>
                    <option value="return">退货退款</option>
                    <option value="exchange">换货</option>
                    <option value="repair">维修</option>
                </select>
            </div>
            
            <div class="form-group">
                <label for="reason">问题描述 *</label>
                <textarea name="reason" id="reason" rows="5" required class="form-control" 
                          placeholder="请详细描述您遇到的问题..."></textarea>
            </div>
            
            <div class="form-group">
                <label>选择需要售后的商品</label>
                <div class="order-items-list">
                    <?php foreach ($order->get_items() as $item_id => $item): ?>
                    <div class="order-item-checkbox">
                        <label>
                            <input type="checkbox" name="items[]" value="<?php echo $item_id; ?>">
                            <?php echo $item->get_name(); ?> × <?php echo $item->get_quantity(); ?>
                        </label>
                    </div>
                    <?php endforeach; ?>
                </div>
            </div>
            
            <div class="form-group">
                <button type="submit" class="btn btn-primary">提交请求</button>
            </div>
            
            <div id="form-message" class="alert" style="display:none;"></div>
        </form>
    </div>
    
    <script>
    jQuery(document).ready(function($) {
        $('#after-sales-request-form').on('submit', function(e) {
            e.preventDefault();
            
            var formData = $(this).serialize();
            
            // 显示加载状态
            $('#form-message').removeClass('alert-success alert-danger')
                             .addClass('alert-info')
                             .html('正在提交，请稍候...')
                             .show();
            
            $.ajax({
                url: '<?php echo rest_url('after-sales/v1/request'); ?>',
                method: 'POST',
                data: formData,
                beforeSend: function(xhr) {
                    xhr.setRequestHeader('X-WP-Nonce', '<?php echo wp_create_nonce('wp_rest'); ?>');
                },
                success: function(response) {
                    if (response.success) {
                        $('#form-message').removeClass('alert-info alert-danger')
                                         .addClass('alert-success')
                                         .html('请求提交成功！' + response.message)
                                         .show();
                        $('#after-sales-request-form')[0].reset();
                    } else {
                        $('#form-message').removeClass('alert-info alert-success')
                                         .addClass('alert-danger')
                                         .html('提交失败：' + response.message)
                                         .show();
                    }
                },
                error: function(xhr, status, error) {
                    var message = '请求失败，请稍后重试';
                    if (xhr.responseJSON && xhr.responseJSON.message) {
                        message = xhr.responseJSON.message;
                    }
                    $('#form-message').removeClass('alert-info alert-success')
                                     .addClass('alert-danger')
                                     .html(message)
                                     .show();
                }
            });
        });
    });
    </script>
    <?php
    
    return ob_get_clean();
}

// 注册短代码
add_shortcode('after_sales_form', 'after_sales_request_form');

方法二：构建模块化、可扩展的售后系统

2.1 设计模块化架构

对于需要更复杂功能的企业，我们需要构建一个模块化的售后系统：

/**
 * 模块化售后系统主类
 */
class Modular_After_Sales_System {
    
    private $modules = array();
    private $settings = array();
    
    /**
     * 初始化系统
     */
    public function init() {
        // 加载配置
        $this->load_settings();
        
        // 注册核心模块
        $this->register_core_modules();
        
        // 允许第三方模块注册
        do_action('after_sales_system_init', $this);
        
        // 初始化所有模块
        $this->initialize_modules();
    }
    
    /**
     * 加载设置
     */
    private function load_settings() {
        $defaults = array(
            'return_period' => 30,
            'refund_methods' => array('original', 'credit'),
            'auto_approve_threshold' => 100, // 自动审批金额阈值
            'enable_partial_refunds' => true,
            'restock_on_return' => true
        );
        
        $this->settings = wp_parse_args(
            get_option('after_sales_settings', array()),
            $defaults
        );
    }
    
    /**
     * 注册核心模块
     */
    private function register_core_modules() {
        // 请求管理模块
        $this->register_module('request_manager', new Request_Manager_Module());
        
        // 退款处理模块
        $this->register_module('refund_processor', new Refund_Processor_Module());
        
        // 物流跟踪模块
        $this->register_module('logistics_tracker', new Logistics_Tracker_Module());
        
        // 通知系统模块
        $this->register_module('notification_system', new Notification_System_Module());
        
        // 数据分析模块
        $this->register_module('analytics', new Analytics_Module());
    }
    
    /**
     * 注册模块
     */
    public function register_module($module_id, $module_instance) {
        if (isset($this->modules[$module_id])) {
            error_log(sprintf('售后系统模块 %s 已注册', $module_id));
            return false;
        }
        
        $this->modules[$module_id] = $module_instance;
        return true;
    }
    
    /**
     * 获取模块
     */
    public function get_module($module_id) {
        return isset($this->modules[$module_id]) ? $this->modules[$module_id] : null;
    }
}

/**
 * 请求管理模块
 */
class Request_Manager_Module {
    
    private $status_flow = array(
        'pending' => array('processing', 'cancelled'),
        'processing' => array('approved', 'rejected', 'cancelled'),
        'approved' => array('refunded', 'exchanged', 'completed'),
        'rejected' => array(),
        'cancelled' => array(),
        'refunded' => array('completed'),
        'exchanged' => array('completed'),
        'completed' => array()
    );
    
    /**
     * 处理状态转换
     */
    public function change_request_status($request_id, $new_status, $notes = '') {
        $current_status = get_post_meta($request_id, '_status', true);
        
        // 检查状态转换是否有效

        if (!isset($this->status_flow[$current_status]) || 
            !in_array($new_status, $this->status_flow[$current_status])) {
            return new WP_Error('invalid_status_transition', 
                sprintf('无法从状态 %s 转换到 %s', $current_status, $new_status));
        }
        
        // 更新状态
        update_post_meta($request_id, '_status', $new_status);
        
        // 记录状态变更历史
        $this->add_status_history($request_id, $current_status, $new_status, $notes);
        
        // 触发状态变更钩子
        do_action('after_sales_request_status_changed', $request_id, $current_status, $new_status, $notes);
        
        return true;
    }
    
    /**
     * 添加状态历史记录
     */
    private function add_status_history($request_id, $from_status, $to_status, $notes) {
        $history = get_post_meta($request_id, '_status_history', true);
        if (!is_array($history)) {
            $history = array();
        }
        
        $history[] = array(
            'from' => $from_status,
            'to' => $to_status,
            'timestamp' => current_time('mysql'),
            'user_id' => get_current_user_id(),
            'notes' => $notes
        );
        
        update_post_meta($request_id, '_status_history', $history);
    }
}

/**
 * 退款处理模块
 */
class Refund_Processor_Module {
    
    /**
     * 处理退款请求
     */
    public function process_refund($request_id) {
        $request = get_post($request_id);
        if (!$request || $request->post_type !== 'after_sales_request') {
            return new WP_Error('invalid_request', '无效的售后请求');
        }
        
        $order_id = get_post_meta($request_id, '_order_id', true);
        $order = wc_get_order($order_id);
        
        if (!$order) {
            return new WP_Error('invalid_order', '订单不存在');
        }
        
        // 获取退款金额
        $refund_amount = $this->calculate_refund_amount($request_id, $order);
        
        // 创建退款
        $refund = wc_create_refund(array(
            'amount' => $refund_amount,
            'reason' => get_post_meta($request_id, '_reason', true),
            'order_id' => $order_id,
            'refund_payment' => true,
            'restock_items' => $this->should_restock_items($request_id)
        ));
        
        if (is_wp_error($refund)) {
            return $refund;
        }
        
        // 更新请求状态
        update_post_meta($request_id, '_refund_id', $refund->get_id());
        update_post_meta($request_id, '_refund_amount', $refund_amount);
        update_post_meta($request_id, '_refund_date', current_time('mysql'));
        
        return $refund->get_id();
    }
    
    /**
     * 计算退款金额
     */
    private function calculate_refund_amount($request_id, $order) {
        $request_type = get_post_meta($request_id, '_request_type', true);
        $request_items = get_post_meta($request_id, '_request_items', true);
        
        // 如果是全额退款
        if (empty($request_items)) {
            return $order->get_total();
        }
        
        // 计算部分退款金额
        $refund_amount = 0;
        foreach ($request_items as $item_id) {
            $item = $order->get_item($item_id);
            if ($item) {
                $refund_amount += $item->get_total();
            }
        }
        
        // 考虑运费和税费
        $refund_amount = $this->adjust_for_fees_and_taxes($refund_amount, $order, $request_items);
        
        return $refund_amount;
    }
}

/**
 * 物流跟踪模块
 */
class Logistics_Tracker_Module {
    
    /**
     * 添加快递跟踪信息
     */
    public function add_tracking_info($request_id, $carrier, $tracking_number, $shipping_date = null) {
        $tracking_info = array(
            'carrier' => $carrier,
            'tracking_number' => $tracking_number,
            'shipping_date' => $shipping_date ?: current_time('mysql'),
            'status' => 'shipped',
            'last_updated' => current_time('mysql')
        );
        
        update_post_meta($request_id, '_tracking_info', $tracking_info);
        
        // 调用快递API获取实时跟踪信息
        $this->update_tracking_status($request_id, $carrier, $tracking_number);
        
        return true;
    }
    
    /**
     * 更新跟踪状态
     */
    private function update_tracking_status($request_id, $carrier, $tracking_number) {
        // 这里可以集成第三方快递API，如快递鸟、快递100等
        $api_response = $this->call_carrier_api($carrier, $tracking_number);
        
        if ($api_response && isset($api_response['status'])) {
            update_post_meta($request_id, '_tracking_status', $api_response['status']);
            update_post_meta($request_id, '_tracking_details', $api_response['details']);
        }
    }
}

2.2 实现RESTful API接口

/**
 * RESTful API接口类
 */
class After_Sales_REST_API {
    
    /**
     * 注册所有API端点
     */
    public function register_endpoints() {
        // 批量获取售后请求
        register_rest_route('after-sales/v2', '/requests', array(
            array(
                'methods' => 'GET',
                'callback' => array($this, 'get_requests'),
                'permission_callback' => array($this, 'check_admin_permission'),
                'args' => $this->get_collection_params()
            ),
            array(
                'methods' => 'POST',
                'callback' => array($this, 'create_request'),
                'permission_callback' => array($this, 'check_create_permission')
            )
        ));
        
        // 单个售后请求操作
        register_rest_route('after-sales/v2', '/requests/(?P<id>d+)', array(
            array(
                'methods' => 'GET',
                'callback' => array($this, 'get_request'),
                'permission_callback' => array($this, 'check_request_permission')
            ),
            array(
                'methods' => 'PUT',
                'callback' => array($this, 'update_request'),
                'permission_callback' => array($this, 'check_admin_permission')
            ),
            array(
                'methods' => 'DELETE',
                'callback' => array($this, 'delete_request'),
                'permission_callback' => array($this, 'check_admin_permission')
            )
        ));
        
        // 状态操作
        register_rest_route('after-sales/v2', '/requests/(?P<id>d+)/status', array(
            'methods' => 'PUT',
            'callback' => array($this, 'update_status'),
            'permission_callback' => array($this, 'check_admin_permission')
        ));
        
        // 退款操作
        register_rest_route('after-sales/v2', '/requests/(?P<id>d+)/refund', array(
            'methods' => 'POST',
            'callback' => array($this, 'process_refund'),
            'permission_callback' => array($this, 'check_admin_permission')
        ));
        
        // 统计信息
        register_rest_route('after-sales/v2', '/stats', array(
            'methods' => 'GET',
            'callback' => array($this, 'get_statistics'),
            'permission_callback' => array($this, 'check_admin_permission')
        ));
    }
    
    /**
     * 获取售后请求列表
     */
    public function get_requests($request) {
        $params = $request->get_params();
        
        $args = array(
            'post_type' => 'after_sales_request',
            'post_status' => 'publish',
            'posts_per_page' => isset($params['per_page']) ? intval($params['per_page']) : 10,
            'paged' => isset($params['page']) ? intval($params['page']) : 1
        );
        
        // 添加过滤条件
        if (!empty($params['status'])) {
            $args['meta_query'][] = array(
                'key' => '_status',
                'value' => $params['status']
            );
        }
        
        if (!empty($params['order_id'])) {
            $args['meta_query'][] = array(
                'key' => '_order_id',
                'value' => intval($params['order_id'])
            );
        }
        
        if (!empty($params['customer_id'])) {
            $args['author'] = intval($params['customer_id']);
        }
        
        if (!empty($params['date_from'])) {
            $args['date_query'][] = array(
                'after' => $params['date_from'],
                'inclusive' => true
            );
        }
        
        if (!empty($params['date_to'])) {
            $args['date_query'][] = array(
                'before' => $params['date_to'],
                'inclusive' => true
            );
        }
        
        $query = new WP_Query($args);
        
        $requests = array();
        foreach ($query->posts as $post) {
            $requests[] = $this->prepare_request_data($post);
        }
        
        $response = new WP_REST_Response($requests);
        
        // 添加分页头信息
        $total = $query->found_posts;
        $total_pages = ceil($total / $args['posts_per_page']);
        
        $response->header('X-WP-Total', $total);
        $response->header('X-WP-TotalPages', $total_pages);
        
        return $response;
    }
    
    /**
     * 准备请求数据
     */
    private function prepare_request_data($post) {
        $meta = get_post_meta($post->ID);
        
        $data = array(
            'id' => $post->ID,
            'title' => $post->post_title,
            'description' => $post->post_content,
            'date' => $post->post_date,
            'customer_id' => $post->post_author,
            'order_id' => isset($meta['_order_id'][0]) ? $meta['_order_id'][0] : null,
            'request_type' => isset($meta['_request_type'][0]) ? $meta['_request_type'][0] : null,
            'status' => isset($meta['_status'][0]) ? $meta['_status'][0] : 'pending',
            'items' => isset($meta['_request_items'][0]) ? maybe_unserialize($meta['_request_items'][0]) : array(),
            'refund_amount' => isset($meta['_refund_amount'][0]) ? $meta['_refund_amount'][0] : null,
            'tracking_info' => isset($meta['_tracking_info'][0]) ? maybe_unserialize($meta['_tracking_info'][0]) : null,
            'status_history' => isset($meta['_status_history'][0]) ? maybe_unserialize($meta['_status_history'][0]) : array()
        );
        
        // 获取客户信息
        $customer = get_userdata($post->post_author);
        if ($customer) {
            $data['customer'] = array(
                'name' => $customer->display_name,
                'email' => $customer->user_email
            );
        }
        
        // 获取订单信息
        if ($data['order_id']) {
            $order = wc_get_order($data['order_id']);
            if ($order) {
                $data['order'] = array(
                    'total' => $order->get_total(),
                    'currency' => $order->get_currency(),
                    'date' => $order->get_date_created()->date('Y-m-d H:i:s')
                );
            }
        }
        
        return $data;
    }
    
    /**
     * 处理退款
     */
    public function process_refund($request) {
        $request_id = $request['id'];
        $parameters = $request->get_params();
        
        $refund_processor = $GLOBALS['after_sales_system']->get_module('refund_processor');
        if (!$refund_processor) {
            return new WP_Error('module_not_found', '退款处理模块未找到', array('status' => 500));
        }
        
        $result = $refund_processor->process_refund($request_id);
        
        if (is_wp_error($result)) {
            return $result;
        }
        
        return array(
            'success' => true,
            'refund_id' => $result,
            'message' => '退款处理成功'
        );
    }
    
    /**
     * 获取统计信息
     */
    public function get_statistics($request) {
        $params = $request->get_params();
        $period = isset($params['period']) ? $params['period'] : 'month'; // day, week, month, year
        
        $stats = array(
            'total_requests' => $this->get_total_requests($period),
            'by_status' => $this->get_requests_by_status($period),
            'by_type' => $this->get_requests_by_type($period),
            'refund_amount' => $this->get_refund_amount($period),
            'processing_time' => $this->get_average_processing_time($period)
        );
        
        return $stats;
    }
    
    /**
     * 获取请求总数
     */
    private function get_total_requests($period) {
        $date_query = $this->get_date_query_for_period($period);
        
        $args = array(
            'post_type' => 'after_sales_request',
            'post_status' => 'publish',
            'date_query' => $date_query,
            'fields' => 'ids',
            'posts_per_page' => -1
        );
        
        $query = new WP_Query($args);
        return $query->found_posts;
    }
}

2.3 实现后台管理界面

/**
 * 后台管理界面
 */
class After_Sales_Admin_Interface {
    
    /**
     * 初始化管理界面
     */
    public function init() {
        add_action('admin_menu', array($this, 'add_admin_pages'));
        add_action('admin_enqueue_scripts', array($this, 'enqueue_admin_scripts'));
        add_action('add_meta_boxes', array($this, 'add_meta_boxes'));
        add_action('save_post_after_sales_request', array($this, 'save_request_meta'));
        
        // 添加列表页列
        add_filter('manage_after_sales_request_posts_columns', array($this, 'add_custom_columns'));
        add_action('manage_after_sales_request_posts_custom_column', array($this, 'render_custom_columns'), 10, 2);
        add_filter('manage_edit-after_sales_request_sortable_columns', array($this, 'make_columns_sortable'));
    }
    
    /**
     * 添加管理页面
     */
    public function add_admin_pages() {
        // 主菜单
        add_menu_page(
            '售后管理',
            '售后管理',
            'manage_woocommerce',
            'after-sales',
            array($this, 'render_dashboard'),
            'dashicons-undo',
            56
        );
        
        // 子菜单
        add_submenu_page(
            'after-sales',
            '售后仪表盘',
            '仪表盘',
            'manage_woocommerce',
            'after-sales',
            array($this, 'render_dashboard')
        );
        
        add_submenu_page(
            'after-sales',
            '售后请求',
            '所有请求',
            'manage_woocommerce',
            'edit.php?post_type=after_sales_request'
        );
        
        add_submenu_page(
            'after-sales',
            '售后设置',
            '设置',
            'manage_woocommerce',
            'after-sales-settings',
            array($this, 'render_settings_page')
        );
        
        add_submenu_page(
            'after-sales',
            '售后报表',
            '报表',
            'manage_woocommerce',
            'after-sales-reports',
            array($this, 'render_reports_page')
        );
    }
    
    /**
     * 渲染仪表盘
     */
    public function render_dashboard() {
        ?>
        <div class="wrap after-sales-dashboard">
            <h1 class="wp-heading-inline">售后管理仪表盘</h1>
            
            <div class="dashboard-widgets">
                <div class="widget-row">
                    <div class="widget-card">
                        <h3>待处理请求</h3>
                        <div class="widget-value" id="pending-requests">0</div>
                        <a href="<?php echo admin_url('edit.php?post_type=after_sales_request&status=pending'); ?>" class="widget-link">查看详情</a>
                    </div>
                    
                    <div class="widget-card">
                        <h3>今日请求</h3>
                        <div class="widget-value" id="today-requests">0</div>
                    </div>
                    
                    <div class="widget-card">
                        <h3>本月退款金额</h3>
                        <div class="widget-value" id="monthly-refund">¥0</div>
                    </div>
                    
                    <div class="widget-card">
                        <h3>平均处理时间</h3>
                        <div class="widget-value" id="avg-processing-time">0小时</div>
                    </div>
                </div>
                
                <div class="widget-row">
                    <div class="widget-large-card">
                        <h3>请求趋势</h3>
                        <div class="chart-container">
                            <canvas id="requests-trend-chart"></canvas>
                        </div>
                    </div>
                    
                    <div class="widget-large-card">
                        <h3>状态分布</h3>