<?php

namespace app\common\service;

class WechatPaymentService extends BasePaymentService
{
    // 微信支付API地址
    protected $apiUrl = 'https://api.mch.weixin.qq.com';

    // 配置参数
    protected $config = [];

    /**
     * 初始化微信支付配置
     */
    protected function initConfig()
    {
        $this->config = [
            'appid' => $this->payConfig['app_id'],
            'mch_id' => $this->payConfig['mch_id'],
            'key' => $this->payConfig['key'],
            'notify_url' => $this->payConfig['notify_url'] ?: url('/api/invitation/payment/wechatNotify', [], true, true)->build(),
            'cert_path' => $this->getCertPath('cert'),
            'key_path' => $this->getCertPath('key'),
        ];

        if (empty($this->config['appid']) || empty($this->config['mch_id']) || empty($this->config['key'])) {
            throw new \Exception('微信支付配置不完整');
        }
    }

    /**
     * 获取证书路径
     */
    protected function getCertPath($type)
    {
        // 可以从数据库或文件系统获取证书
        // 这里简化处理，实际需要根据业务获取
        return '';
    }

    /**
     * 生成支付二维码
     */
    public function createQrCode($orderNo, $amount, $subject, $body = '')
    {
        try {
            // 构建请求参数
            $params = [
                'appid' => $this->config['appid'],
                'mch_id' => $this->config['mch_id'],
                'nonce_str' => $this->generateNonceStr(),
                'body' => mb_substr($subject, 0, 127, 'UTF-8'), // 商品描述，128字节限制
                'out_trade_no' => $orderNo,
                'total_fee' => intval($amount * 100), // 单位：分
                'spbill_create_ip' => request()->ip(),
                'notify_url' => $this->config['notify_url'],
                'trade_type' => 'NATIVE', // 扫码支付
                'product_id' => $orderNo,
            ];

            // 生成签名
            $params['sign'] = $this->generateSign($params);

            // 调用微信统一下单接口
            $result = $this->postXmlCurl($this->apiUrl . '/pay/unifiedorder', $this->arrayToXml($params));

            // 解析结果
            $response = $this->xmlToArray($result);
            if ($response['return_code'] == 'SUCCESS' && $response['result_code'] == 'SUCCESS') {
                return [
                    'qr_code_url' => $response['code_url'],
                    'qr_code_content' => $response['code_url'],
                    'prepay_id' => $response['prepay_id'],
                ];
            } else {
                $errorMsg = $response['return_msg'] ?? $response['err_code_des'] ?? '微信支付下单失败';
                throw new \Exception($errorMsg);
            }

        } catch (\Throwable $e) {
            $this->log('生成微信支付二维码失败', [
                'order_no' => $orderNo,
                'error' => $e->getMessage()
            ], 'error');
            throw $e;
        }
    }

    /**
     * 处理支付回调
     */
    public function handleNotify($input)
    {
        try {
            // 解析XML数据
            $data = $this->xmlToArray($input);

            // 验证签名
            if (!$this->verifySign($data, $data['sign'])) {
                throw new \Exception('签名验证失败');
            }

            // 检查支付状态
            if ($data['return_code'] != 'SUCCESS' || $data['result_code'] != 'SUCCESS') {
                throw new \Exception('支付失败: ' . ($data['return_msg'] ?? '未知错误'));
            }

            return [
                'order_no' => $data['out_trade_no'],
                'trade_no' => $data['transaction_id'],
                'pay_amount' => $data['total_fee'] / 100,
                'pay_time' => $this->formatWxTime($data['time_end']),
                'raw_data' => $data,
            ];

        } catch (\Throwable $e) {
            $this->log('处理微信支付回调失败', [
                'input' => $input,
                'error' => $e->getMessage()
            ], 'error');
            throw $e;
        }
    }

    /**
     * 查询支付订单
     */
    public function queryOrder($orderNo)
    {
        try {
            $params = [
                'appid' => $this->config['appid'],
                'mch_id' => $this->config['mch_id'],
                'out_trade_no' => $orderNo,
                'nonce_str' => $this->generateNonceStr(),
            ];

            $params['sign'] = $this->generateSign($params);

            $result = $this->postXmlCurl($this->apiUrl . '/pay/orderquery', $this->arrayToXml($params));
            $response = $this->xmlToArray($result);

            if ($response['return_code'] == 'SUCCESS' && $response['result_code'] == 'SUCCESS') {
                $status = $response['trade_state'];
                $payStatus = 0; // 待支付

                if ($status == 'SUCCESS') {
                    $payStatus = 1; // 已支付
                } elseif (in_array($status, ['CLOSED', 'REVOKED', 'PAYERROR', 'USERPAYING'])) {
                    $payStatus = 2; // 支付失败
                }

                return [
                    'order_no' => $response['out_trade_no'],
                    'trade_no' => $response['transaction_id'],
                    'pay_status' => $payStatus,
                    'pay_amount' => $response['total_fee'] / 100,
                    'pay_time' => isset($response['time_end']) ? $this->formatWxTime($response['time_end']) : null,
                    'trade_state' => $status,
                ];
            }

            throw new \Exception('查询订单失败: ' . ($response['return_msg'] ?? '未知错误'));

        } catch (\Throwable $e) {
            $this->log('查询微信支付订单失败', [
                'order_no' => $orderNo,
                'error' => $e->getMessage()
            ], 'error');
            throw $e;
        }
    }

    /**
     * 验证签名
     */
    protected function verifySign($data, $sign)
    {
        $localSign = $this->generateSign($data);
        return $localSign === $sign;
    }

    /**
     * 生成签名
     */
    protected function generateSign($data)
    {
        // 过滤空值和sign参数
        $filterData = array_filter($data, function($value, $key) {
            return $value !== '' && $value !== null && $key !== 'sign';
        }, ARRAY_FILTER_USE_BOTH);

        // 按参数名ASCII码从小到大排序
        ksort($filterData);

        // 拼接字符串
        $string = '';
        foreach ($filterData as $key => $value) {
            $string .= $key . '=' . $value . '&';
        }
        $string .= 'key=' . $this->config['key'];

        // MD5加密并转为大写
        return strtoupper(md5($string));
    }

    /**
     * 生成随机字符串
     */
    protected function generateNonceStr($length = 32)
    {
        $chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
        $str = '';
        for ($i = 0; $i < $length; $i++) {
            $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
        }
        return $str;
    }

    /**
     * 格式化微信支付时间
     */
    protected function formatWxTime($timeStr)
    {
        if (empty($timeStr)) return null;

        // 微信时间格式：yyyyMMddHHmmss
        $year = substr($timeStr, 0, 4);
        $month = substr($timeStr, 4, 2);
        $day = substr($timeStr, 6, 2);
        $hour = substr($timeStr, 8, 2);
        $minute = substr($timeStr, 10, 2);
        $second = substr($timeStr, 12, 2);

        return "{$year}-{$month}-{$day} {$hour}:{$minute}:{$second}";
    }

    /**
     * 发送XML请求
     */
    private function postXmlCurl($url, $xml, $useCert = false, $timeout = 30)
    {
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $xml);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);

        // 设置SSL
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);

        // 如果需要证书
        if ($useCert) {
            curl_setopt($ch, CURLOPT_SSLCERTTYPE, 'PEM');
            curl_setopt($ch, CURLOPT_SSLCERT, $this->config['cert_path']);
            curl_setopt($ch, CURLOPT_SSLKEYTYPE, 'PEM');
            curl_setopt($ch, CURLOPT_SSLKEY, $this->config['key_path']);
        }

        $response = curl_exec($ch);

        if (curl_errno($ch)) {
            curl_close($ch);
            throw new \Exception('CURL错误: ' . curl_error($ch));
        }

        curl_close($ch);
        return $response;
    }

    /**
     * 数组转XML
     */
    private function arrayToXml($arr)
    {
        $xml = '<xml>';
        foreach ($arr as $key => $val) {
            if (is_numeric($val)) {
                $xml .= "<{$key}>{$val}</{$key}>";
            } else {
                $xml .= "<{$key}><![CDATA[{$val}]]></{$key}>";
            }
        }
        $xml .= '</xml>';
        return $xml;
    }

    /**
     * XML转数组（兼容PHP 8.0+）
     */
    private function xmlToArray($xml)
    {
        if (empty($xml)) {
            return [];
        }

        try {
            // 方法1：使用DOMDocument（推荐，兼容性好）
            $dom = new \DOMDocument();

            // 针对PHP版本的兼容处理
            if (version_compare(PHP_VERSION, '8.0.0', '>=')) {
                // PHP 8.0+ 不需要禁用实体加载器，直接加载
                $dom->loadXML($xml, LIBXML_NOENT | LIBXML_NOCDATA);
            } else {
                // PHP 8.0以下需要禁用实体加载器
                $previous = libxml_disable_entity_loader(true);
                $dom->loadXML($xml, LIBXML_NOENT | LIBXML_NOCDATA);
                libxml_disable_entity_loader($previous);
            }

            // 转换为数组
            $data = $this->domToArray($dom->documentElement);

            return $data ?: [];

        } catch (\Exception $e) {
            $this->log('XML解析失败', [
                'xml' => substr($xml, 0, 500), // 只记录前500字符
                'error' => $e->getMessage()
            ], 'error');

            // 备用解析方法
            return $this->fallbackXmlToArray($xml);
        }
    }

    /**
     * DOMElement转换为数组
     */
    private function domToArray($node)
    {
        $output = [];

        switch ($node->nodeType) {
            case XML_CDATA_SECTION_NODE:
            case XML_TEXT_NODE:
                $output = trim($node->textContent);
                break;

            case XML_ELEMENT_NODE:
                for ($i = 0; $i < $node->childNodes->length; $i++) {
                    $child = $node->childNodes->item($i);
                    $value = $this->domToArray($child);

                    if (isset($child->tagName)) {
                        $tag = $child->tagName;

                        if (!isset($output[$tag])) {
                            $output[$tag] = [];
                        }

                        if (is_array($value) && isset($value['@value'])) {
                            $output[$tag][] = $value['@value'];
                        } else {
                            $output[$tag][] = $value;
                        }

                        // 如果是单一元素，不要数组形式
                        if (count($output[$tag]) === 1 && !is_array($output[$tag][0])) {
                            $output[$tag] = $output[$tag][0];
                        }
                    } elseif ($value !== '') {
                        $output = $value;
                    }
                }

                if ($node->attributes->length) {
                    $attributes = [];
                    foreach ($node->attributes as $attrName => $attrNode) {
                        $attributes[$attrName] = (string)$attrNode->value;
                    }
                    if (!empty($output)) {
                        $output['@attributes'] = $attributes;
                    } else {
                        $output = ['@value' => '', '@attributes' => $attributes];
                    }
                }
                break;
        }

        // 如果是数组且只有一个元素，直接返回那个元素
        if (is_array($output) && count($output) == 1 && isset($output[0])) {
            $output = $output[0];
        }

        return $output;
    }

    /**
     * 备用XML解析方法（原来的方法，带版本检查）
     */
    private function fallbackXmlToArray($xml)
    {
        try {
            // 版本检查，PHP 8.0以上不调用已废弃函数
            if (version_compare(PHP_VERSION, '8.0.0', '<')) {
                libxml_disable_entity_loader(true);
            }

            $data = json_decode(json_encode(simplexml_load_string(
                $xml,
                'SimpleXMLElement',
                LIBXML_NOCDATA | LIBXML_NOENT
            )), true);

            return $data ?: [];
        } catch (\Exception $e) {
            $this->log('备用XML解析失败', [
                'error' => $e->getMessage()
            ], 'error');
            return [];
        }
    }
}