<?php

namespace app\common\service;

use app\common\model\User;
use EasyWeChat\Kernel\Encryptor;
use think\Cache;
use think\Log;

/**
 * 小程序虚拟支付（代币充值）
 * 文档：https://developers.weixin.qq.com/miniprogram/dev/platform-capabilities/business-capabilities/virtual-payment.html
 * 客户端：wx.requestVirtualPayment，mode=short_series_coin
 * 服务器：/xpay/query_order 确认现金单，/xpay/currency_pay 扣减代币
 */
class VirtualPayService
{
    const SESSION_PREFIX = 'wx_session_key:';
    const TRADE_PREFIX = 'vp_trade:';
    const LATEST_PREFIX = 'vp_order_latest:';
    const PLATFORM_PREFIX = 'vp_pay_platform:';
    const CACHE_TTL = 1296000; // 15天

    /**
     * 登录成功后缓存 session_key，用户态签名要用
     * @param int $userId
     * @param string $sessionKey
     */
    public static function saveSessionKey($userId, $sessionKey)
    {
        if (!$userId || $sessionKey === '') {
            return;
        }
        Cache::set(self::SESSION_PREFIX . $userId, $sessionKey, self::CACHE_TTL);
    }

    /**
     * 记下客户拉起支付时的终端。iOS 单独记，鸿蒙、Windows 等按安卓费率
     * @param string $orderNo
     * @param string $platform
     * @return string
     */
    public static function rememberPayPlatform($orderNo, $platform)
    {
        $normalized = self::normalizePayPlatform($platform);
        if ($orderNo !== '' && $normalized !== '') {
            Cache::set(self::PLATFORM_PREFIX . $orderNo, $normalized, self::CACHE_TTL);
        }

        return $normalized;
    }

    /**
     * @param string $orderNo
     * @return string
     */
    public static function payPlatformOf($orderNo)
    {
        $cached = $orderNo ? Cache::get(self::PLATFORM_PREFIX . $orderNo) : '';

        return self::normalizePayPlatform($cached);
    }

    /**
     * @param string $platform
     * @return string android|ios|空
     */
    public static function normalizePayPlatform($platform)
    {
        $platform = strtolower(trim((string)$platform));
        if ($platform === 'ios' || $platform === 'iphone') {
            return 'ios';
        }
        if ($platform === '') {
            return '';
        }

        return 'android';
    }

    /**
     * 生成 wx.requestVirtualPayment 参数。signData 必须原样传给客户端，不能再 JSON.stringify
     * @param string $orderNo
     * @param float|string $amountYuan
     * @param string $openid
     * @return array
     * @throws \Exception
     */
    public static function createClientPay($orderNo, $amountYuan, $openid)
    {
        $offerId = (string)(self::payConfig()['offer_id'] ?? '');
        if ($offerId === '') {
            self::logMissingOfferId();
            throw new \Exception('未配置虚拟支付 OfferID');
        }
        $buyQuantity = self::coinQuantity($amountYuan);
        $outTradeNo = 'V' . date('ymdHis') . substr(md5(uniqid('', true)), 0, 10);
        $signData = json_encode([
            'offerId' => $offerId,
            'buyQuantity' => $buyQuantity,
            'env' => self::env(),
            'currencyType' => 'CNY',
            'outTradeNo' => $outTradeNo,
            'attach' => (string)$orderNo,
        ], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
        if ($signData === false) {
            throw new \Exception('虚拟支付参数编码失败');
        }
        $sessionKey = self::sessionKeyByOpenid($openid);
        Cache::set(self::TRADE_PREFIX . $outTradeNo, (string)$orderNo, self::CACHE_TTL);
        Cache::set(self::LATEST_PREFIX . $orderNo, $outTradeNo, self::CACHE_TTL);
        Log::info('虚拟支付下单 ' . json_encode([
            'order_no' => $orderNo,
            'out_trade_no' => $outTradeNo,
            'buy_quantity' => $buyQuantity,
            'env' => self::env(),
        ], JSON_UNESCAPED_UNICODE));

        return [
            'mode' => 'short_series_coin',
            'signData' => $signData,
            'paySig' => hash_hmac('sha256', 'requestVirtualPayment&' . $signData, self::appKey()),
            'signature' => hash_hmac('sha256', $signData, $sessionKey),
        ];
    }

    /**
     * 现金单已支付时扣减代币并入账。没有可确认的支付单时返回 false，调用方再拉起新的支付
     * @param string $orderNo
     * @param string $openid
     * @return bool
     * @throws \Exception
     */
    public static function settleIfPaid($orderNo, $openid)
    {
        $order = OrderService::getOne(['order_no' => $orderNo]);
        if (!$order) {
            throw new \Exception('订单不存在');
        }
        if ((int)$order->order_status !== OrderService::ORDER_STATUS_WAIT_PAY) {
            return in_array((int)$order->order_status, [
                OrderService::ORDER_STATUS_WAIT_SHIP,
                OrderService::ORDER_STATUS_SHIPPED,
                OrderService::ORDER_STATUS_FINISHED,
            ], true);
        }
        $outTradeNo = Cache::get(self::LATEST_PREFIX . $orderNo);
        if (!$outTradeNo) {
            return false;
        }
        $res = self::queryOrder($openid, $outTradeNo);
        if ((int)($res['errcode'] ?? -1) !== 0) {
            Log::info('虚拟支付查单未支付 ' . json_encode([
                'order_no' => $orderNo,
                'out_trade_no' => $outTradeNo,
                'res' => $res,
            ], JSON_UNESCAPED_UNICODE));
            return false;
        }
        $wxOrder = $res['order'] ?? [];
        $status = (int)($wxOrder['status'] ?? 0);
        // 2已支付待发货 3发货中 4已发货。代币由平台入账，这三种都表示现金已支付
        if (!in_array($status, [2, 3, 4], true)) {
            return false;
        }
        self::deductCoins($order, $openid, $wxOrder);

        return true;
    }

    /**
     * 处理虚拟支付消息推送
     * @param array $msg
     * @return array
     * @throws \Exception
     */
    public static function handleMessage(array $msg)
    {
        $event = (string)($msg['Event'] ?? '');
        if ($event === 'xpay_coin_pay_notify') {
            self::finishFromCoinNotify($msg);
            return ['ErrCode' => 0, 'ErrMsg' => 'success'];
        }
        if ($event === 'xpay_refund_notify') {
            self::handleRefundNotify($msg);
            return ['ErrCode' => 0, 'ErrMsg' => 'success'];
        }
        if ($event === 'xpay_subscribe_ios_refund_query_notify') {
            return self::iosRefundQuery($msg);
        }
        Log::info('虚拟支付推送 ' . $event . ' ' . json_encode($msg, JSON_UNESCAPED_UNICODE));

        return ['ErrCode' => 0, 'ErrMsg' => 'success'];
    }

    /**
     * 解密安全模式下的消息，返回明文字符串
     * @param string $encrypt
     * @param string $msgSignature
     * @param string $nonce
     * @param string $timestamp
     * @return string
     * @throws \Exception
     */
    public static function decryptMessage($encrypt, $msgSignature, $nonce, $timestamp)
    {
        $payConfig = self::payConfig();
        $wechat = config('common.wechat');
        $token = (string)($payConfig['msg_token'] ?? '');
        $aesKey = (string)($payConfig['aes_key'] ?? '');
        $appId = is_array($wechat) ? (string)($wechat['app_id'] ?? '') : '';
        if ($token === '' || $aesKey === '' || $appId === '') {
            throw new \Exception('未配置虚拟支付消息加解密参数');
        }
        $encryptor = new Encryptor($appId, $token, $aesKey);

        return $encryptor->decrypt($encrypt, $msgSignature, $nonce, $timestamp);
    }

    /**
     * @param string $openid
     * @param string $outTradeNo
     * @return array
     * @throws \Exception
     */
    private static function queryOrder($openid, $outTradeNo)
    {
        return self::postXpay('/xpay/query_order', [
            'openid' => $openid,
            'env' => self::env(),
            'order_id' => (string)$outTradeNo,
        ]);
    }

    /**
     * 校验现金金额后扣减代币，再把业务订单标成已支付
     * @param \think\Model $order
     * @param string $openid
     * @param array $wxOrder
     * @throws \Exception
     */
    private static function deductCoins($order, $openid, array $wxOrder)
    {
        $paidFee = (int)($wxOrder['paid_fee'] ?? 0);
        if ($paidFee <= 0) {
            $paidFee = (int)($wxOrder['order_fee'] ?? 0);
        }
        $expect = self::amountFen($order->payment_amount);
        if ($paidFee !== $expect) {
            Log::error('虚拟支付金额不一致 ' . json_encode([
                'order_no' => $order->order_no,
                'paid_fee' => $paidFee,
                'expect' => $expect,
            ], JSON_UNESCAPED_UNICODE));
            throw new \Exception('支付金额与订单不一致');
        }
        $buyQuantity = self::coinQuantity($order->payment_amount);
        $res = self::postXpay('/xpay/currency_pay', [
            'openid' => $openid,
            'env' => self::env(),
            'user_ip' => self::userIp(),
            'amount' => $buyQuantity,
            'order_id' => (string)$order->order_no,
            'payitem' => json_encode([[
                'productid' => 'order',
                'unit_price' => $buyQuantity,
                'quantity' => 1,
            ]], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES),
            'remark' => '订单' . $order->order_no,
        ], self::sessionKeyByOpenid($openid));
        $errcode = (int)($res['errcode'] ?? -1);
        // 268490004：重复扣减，上一笔已经成功
        if ($errcode !== 0 && $errcode !== 268490004) {
            if ($errcode === 268490006) {
                throw new \Exception('支付确认中，请稍后在订单里再次点击支付，不会重复扣款');
            }
            throw new \Exception('代币扣减失败：' . ($res['errmsg'] ?? '未知错误'));
        }
        $transactionId = (string)($wxOrder['wxpay_order_id'] ?? ($wxOrder['channel_order_id'] ?? ''));
        $paidTime = (int)($wxOrder['paid_time'] ?? 0);
        OrderService::finishPaid(
            $order->order_no,
            $expect,
            $transactionId,
            'XPAY',
            $paidTime > 0 ? $paidTime : time(),
            'settle',
            self::payPlatformOf($order->order_no)
        );
    }

    /**
     * @param array $msg
     * @throws \Exception
     */
    private static function finishFromCoinNotify(array $msg)
    {
        $outTradeNo = (string)($msg['OutTradeNo'] ?? '');
        $orderNo = Cache::get(self::TRADE_PREFIX . $outTradeNo) ?: $outTradeNo;
        $coinInfo = isset($msg['CoinInfo']) && is_array($msg['CoinInfo']) ? $msg['CoinInfo'] : [];
        $order = OrderService::getOne(['order_no' => $orderNo]);
        if (!$order) {
            Log::error('虚拟支付代币通知未找到订单 ' . $outTradeNo);
            return;
        }
        $fen = isset($coinInfo['ActualPrice']) ? (int)$coinInfo['ActualPrice'] : self::amountFen($order->payment_amount);
        $payInfo = isset($msg['WeChatPayInfo']) && is_array($msg['WeChatPayInfo']) ? $msg['WeChatPayInfo'] : [];
        $paidTime = (int)($payInfo['PaidTime'] ?? 0);
        OrderService::finishPaid(
            $orderNo,
            $fen,
            (string)($payInfo['TransactionId'] ?? ''),
            'XPAY',
            $paidTime > 0 ? $paidTime : time(),
            'coin_notify',
            self::payPlatformOf($orderNo)
        );
    }

    /**
     * 未发货的订单退款成功后改为已退款。已发货或需求单只记日志，避免把已结算合同改回去
     * @param array $msg
     */
    private static function handleRefundNotify(array $msg)
    {
        Log::info('虚拟支付退款通知 ' . json_encode($msg, JSON_UNESCAPED_UNICODE));
        if ((int)($msg['RetCode'] ?? 1) !== 0) {
            return;
        }
        $mchOrderId = (string)($msg['MchOrderId'] ?? '');
        $orderNo = Cache::get(self::TRADE_PREFIX . $mchOrderId) ?: $mchOrderId;
        $order = OrderService::getOne(['order_no' => $orderNo]);
        if (!$order) {
            Log::error('虚拟支付退款未找到订单 ' . $mchOrderId);
            return;
        }
        if ((int)$order->order_status === OrderService::ORDER_STATUS_WAIT_SHIP
            && (int)$order->order_type === OrderService::ORDER_TYPE_SOFTWARE) {
            OrderService::where('order_no', $order->order_no)->update([
                'order_status' => OrderService::ORDER_STATUS_REFUNDED,
            ]);
        }
    }

    /**
     * iOS 退款问询：已交付建议拒绝，未交付建议退款。最终由苹果决定
     * @param array $msg
     * @return array
     */
    private static function iosRefundQuery(array $msg)
    {
        $payOrderId = (string)($msg['pay_order_id'] ?? ($msg['PayOrderId'] ?? ''));
        $orderNo = $payOrderId ? (Cache::get(self::TRADE_PREFIX . $payOrderId) ?: $payOrderId) : '';
        $order = $orderNo ? OrderService::getOne(['order_no' => $orderNo]) : null;
        $delivered = $order && in_array((int)$order->order_status, [
            OrderService::ORDER_STATUS_SHIPPED,
            OrderService::ORDER_STATUS_FINISHED,
        ], true);
        if ($delivered) {
            return [
                'result_code' => 1,
                'result_info' => '已交付',
                'evidence' => '虚拟商品已交付，建议拒绝退款',
            ];
        }

        return [
            'result_code' => 0,
            'result_info' => '未交付',
            'evidence' => '订单未交付，建议退款',
        ];
    }

    /**
     * @param string $uri
     * @param array $payload
     * @param string $sessionKey 需要用户态签名的接口才传
     * @return array
     * @throws \Exception
     */
    private static function postXpay($uri, array $payload, $sessionKey = '')
    {
        $body = json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
        if ($body === false) {
            throw new \Exception('虚拟支付参数编码失败');
        }
        $service = new EasyWeChatService();
        $result = self::requestXpay($service, $uri, $body, $sessionKey);
        $errcode = (int)($result['errcode'] ?? 0);
        // 40001 凭证不是最新，42001 凭证过期。刷新后只重试一次
        if ($errcode === 40001 || $errcode === 42001) {
            Log::info('虚拟支付 access_token 失效，刷新后重试 ' . $uri);
            $service->refreshMiniAccessToken(true);
            $result = self::requestXpay($service, $uri, $body, $sessionKey);
        }
        Log::info('虚拟支付请求 ' . $uri . ' ' . json_encode([
            'payload' => $payload,
            'res' => $result,
        ], JSON_UNESCAPED_UNICODE));

        return is_array($result) ? $result : [];
    }

    /**
     * @param EasyWeChatService $service
     * @param string $uri
     * @param string $body
     * @param string $sessionKey
     * @return array
     * @throws \Exception
     */
    private static function requestXpay(EasyWeChatService $service, $uri, $body, $sessionKey)
    {
        // access_token 由小程序 HTTP 客户端自动附在 query 上，不参与 pay_sig
        $query = [
            'pay_sig' => hash_hmac('sha256', $uri . '&' . $body, self::appKey()),
        ];
        if ($sessionKey !== '') {
            $query['signature'] = hash_hmac('sha256', $body, $sessionKey);
        }
        try {
            $response = $service->app->getClient()->post($uri, [
                'query' => $query,
                'headers' => ['Content-Type' => 'application/json'],
                'body' => $body,
            ]);
            $result = $response->toArray(false);
        } catch (\Exception $e) {
            Log::error('虚拟支付请求异常 ' . $uri . ' ' . $e->getMessage());
            throw new \Exception('虚拟支付请求失败');
        }

        return is_array($result) ? $result : [];
    }

    /**
     * @param string $openid
     * @return string
     * @throws \Exception
     */
    private static function sessionKeyByOpenid($openid)
    {
        $userId = User::where('openid', $openid)->value('id');
        $sessionKey = $userId ? Cache::get(self::SESSION_PREFIX . $userId) : '';
        if (!$sessionKey) {
            throw new \Exception('登录态已过期，请退出小程序后重新进入再支付');
        }

        return (string)$sessionKey;
    }

    /**
     * ThinkPHP 5 的 config() 只按第一个点拆成两级，三级键会读成空
     * @return array
     */
    private static function payConfig()
    {
        $config = config('common.virtual_pay');

        return is_array($config) ? $config : [];
    }

    /**
     * OfferID 为空时记下 .env 有没有被读到，不记录密钥内容
     */
    private static function logMissingOfferId()
    {
        $envFile = (defined('ROOT_PATH') ? ROOT_PATH : '') . '.env';
        $exists = $envFile !== '.env' && is_file($envFile);
        $section = '';
        $found = null;
        if ($exists) {
            $lines = file($envFile, FILE_IGNORE_NEW_LINES);
            if (is_array($lines)) {
                foreach ($lines as $line) {
                    $trim = trim($line);
                    if ($trim === '' || $trim[0] === ';' || $trim[0] === '#') {
                        continue;
                    }
                    if (preg_match('/^\[(.+)\]$/', $trim, $sectionMatch)) {
                        $section = $sectionMatch[1];
                        continue;
                    }
                    if (preg_match('/^vp_offer_id\s*=\s*(.*)$/', $trim, $valueMatch)) {
                        $value = trim($valueMatch[1], " \t\"'");
                        $found = [
                            'section' => $section,
                            'len' => strlen($value),
                        ];
                    }
                }
            }
        }
        $fromEnv = getenv('PHP_WECHAT_VP_OFFER_ID');
        $virtualPay = config('common.virtual_pay');
        Log::error('虚拟支付 OfferID 为空 ' . json_encode([
            'env_file' => $envFile,
            'env_exists' => $exists,
            'file_item' => $found ?: 'missing',
            'getenv' => $fromEnv === false ? 'false' : ('len:' . strlen(trim((string)$fromEnv))),
            'config_keys' => is_array($virtualPay) ? array_keys($virtualPay) : gettype($virtualPay),
        ], JSON_UNESCAPED_UNICODE));
    }

    /**
     * 代币数量，保留两位小数。1元=1代币时，0.01元对应 0.01 个代币
     * @param float|string $amountYuan
     * @return float
     * @throws \Exception
     */
    private static function coinQuantity($amountYuan)
    {
        $fen = self::amountFen($amountYuan);
        if ($fen < 1) {
            throw new \Exception('支付金额不能小于0.01元');
        }
        $coinPerYuan = (int)(self::payConfig()['coin_per_yuan'] ?? 0);
        if ($coinPerYuan < 1) {
            $coinPerYuan = 1;
        }
        $quantity = bcdiv(bcmul((string)$fen, (string)$coinPerYuan, 0), '100', 2);

        return (float)$quantity;
    }

    /**
     * @param float|string $amountYuan
     * @return int
     */
    private static function amountFen($amountYuan)
    {
        return (int)bcmul(sprintf('%.2f', $amountYuan), '100', 0);
    }

    /**
     * @return int
     */
    private static function env()
    {
        return (int)(self::payConfig()['env'] ?? 0) === 1 ? 1 : 0;
    }

    /**
     * @return string
     * @throws \Exception
     */
    private static function appKey()
    {
        $config = self::payConfig();
        $key = self::env() === 1 ? (string)($config['sandbox_app_key'] ?? '') : (string)($config['app_key'] ?? '');
        if ($key === '') {
            throw new \Exception('未配置虚拟支付 AppKey');
        }

        return $key;
    }

    /**
     * @return string
     */
    private static function userIp()
    {
        $ip = request()->ip();
        if (!filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) {
            return '127.0.0.1';
        }

        return $ip;
    }
}