<?php

namespace app\common\library;

use addons\epay\library\Service as EpayService;
use think\Db;
use think\Log;

/**
 * 订单退款（微信原路退回 / 余额退回 + 业务回滚 + 佣金冲销）
 *
 * 规则：
 *   1. 只有 status=paid 的订单可退；
 *   2. 退款金额 > 0、≤ 订单实付金额，同一订单只退一次；
 *   3. 微信订单先调微信退款接口，受理成功后才改库；余额订单直接退回余额；
 *   4. 退款后按订单类型回滚权益：
 *        recharge → 扣回余额（余额不足则拒绝退款）
 *        payview  → 删除解锁记录
 *        member   → 按套餐天数/条数扣减会员权益
 *        post     → 信息保留（由运营决定是否下架）
 *   5. 无论哪种订单，退款都会冲销该订单产生的分销佣金（防止“退款后仍拿佣金”）。
 */
class OrderRefund
{
    /**
     * @param int        $orderId
     * @param float|null $amount 不传则全额退款
     * @param string     $reason
     * @return array{refundNo:string,amount:float}
     * @throws \Exception
     */
    public static function refund($orderId, $amount = null, $reason = '')
    {
        $order = Db::name('fc_order')->where('id', (int)$orderId)->find();
        if (!$order) {
            throw new \Exception('订单不存在');
        }
        if ((string)$order['status'] !== 'paid') {
            throw new \Exception('只有已支付订单可以退款');
        }

        $paid = round((float)$order['amount'], 2);
        $amount = $amount === null ? $paid : round((float)$amount, 2);
        if ($amount <= 0) {
            throw new \Exception('退款金额需大于 0');
        }
        if ($amount > $paid) {
            throw new \Exception('退款金额不能超过订单实付金额 ' . $paid . ' 元');
        }

        $payType = (string)$order['pay_type'];
        if (!in_array($payType, ['wxpay', 'balance'], true)) {
            throw new \Exception('该订单支付方式不支持退款');
        }

        // 充值订单：余额必须足够扣回，否则先拒绝（避免钱退了余额扣不回来）
        if ((string)$order['type'] === 'recharge') {
            $balance = (float)Db::name('user')->where('id', (int)$order['user_id'])->value('money');
            if ($balance < $amount) {
                throw new \Exception('用户当前余额不足 ' . $amount . ' 元，无法退回该笔充值（请先冻结或人工处理）');
            }
        }

        $refundNo = $payType === 'wxpay' ? self::refundNo($order) : '';

        // 0) 原子抢占：paid → refunding，避免并发重复退款（两个请求都调微信）
        $claimed = Db::name('fc_order')
            ->where('id', (int)$order['id'])
            ->where('status', 'paid')
            ->update([
                'status'        => 'refunding',
                'out_refund_no' => $refundNo,
                'updatetime'    => time(),
            ]);
        if (!$claimed) {
            throw new \Exception('订单正在退款或已退款，请勿重复操作');
        }

        // 1) 微信订单先退款（外部调用，放在事务外）
        if ($payType === 'wxpay') {
            try {
                self::requestWechatRefund($order, $refundNo, $amount, $reason);
            } catch (\Throwable $e) {
                // 退款未受理：回退为已支付，允许重新操作
                Db::name('fc_order')->where('id', (int)$order['id'])->where('status', 'refunding')->update([
                    'status'        => 'paid',
                    'out_refund_no' => '',
                    'updatetime'    => time(),
                ]);
                throw $e;
            }
        }

        $now = time();
        Db::transaction(function () use ($order, $amount, $reason, $refundNo, $now, $payType) {
            // 行锁 + 二次校验：此时应为 refunding
            $locked = Db::name('fc_order')->where('id', (int)$order['id'])->lock(true)->find();
            if (!$locked || (string)$locked['status'] !== 'refunding') {
                throw new \Exception('订单状态已变化，退款未写入');
            }

            Db::name('fc_order')->where('id', (int)$order['id'])->update([
                'status'        => 'refunded',
                'refund_amount' => $amount,
                'refund_reason' => (string)$reason,
                'out_refund_no' => $refundNo,
                'updatetime'    => $now,
            ]);

            $userId = (int)$locked['user_id'];

            // 2) 余额订单：直接退回余额
            if ($payType === 'balance') {
                Db::name('user')->where('id', $userId)->setInc('money', $amount);
                $balance = round((float)Db::name('user')->where('id', $userId)->value('money'), 2);

                self::addFlow('income', '订单退款(余额)', $amount, $balance, (int)$locked['id'], '余额退款', $userId);
                // 钱包流水（fa_user.money 增）→ 余额中心「余额明细」
                self::addWalletFlow($userId, 'income', '订单退款(余额)', $amount, $balance, (int)$locked['id'], '余额退款');
            } else {
                self::addFlow('expense', '订单退款', $amount, 0, (int)$locked['id'], '微信退款 ' . $refundNo, $userId);
            }

            // 3) 权益回滚
            self::rollbackBenefits($locked, $amount, $now);

            // 3.5) 退回优惠券（退款后券可再次使用）
            CouponService::release((string)$locked['order_no']);

            // 4) 分销佣金冲销（所有支付方式都要做）
            self::reverseCommission($locked, $now);

            Db::name('fc_message')->insert([
                'user_id'    => $userId,
                'type'       => 'system',
                'title'      => '订单已退款',
                'content'    => '您的订单「' . $locked['title'] . '」已退款 ' . $amount . ' 元'
                    . ($payType === 'balance' ? '，已退回账户余额。' : '，将按原支付路径退回。'),
                'isread'     => 0,
                'createtime' => $now,
            ]);
        });

        Log::record('订单退款成功：订单 ' . $order['order_no'] . '，退款单号 ' . ($refundNo ?: '-') . '，金额 ' . $amount . ' 元，方式 ' . $payType, 'info');

        return ['refundNo' => $refundNo, 'amount' => $amount];
    }

    /**
     * 退款结果回调处理（微信 V3）
     *
     * @param array $data 解密后的回调数据
     * @return string 处理结果
     */
    public static function handleNotify(array $data)
    {
        $outRefundNo = isset($data['out_refund_no']) ? (string)$data['out_refund_no'] : '';
        if ($outRefundNo === '') {
            return 'ignored';
        }

        $order = Db::name('fc_order')->where('out_refund_no', $outRefundNo)->find();
        if (!$order) {
            Log::record('微信退款回调：未找到订单 out_refund_no=' . $outRefundNo, 'error');
            return 'ignored';
        }

        $status = strtoupper((string)(isset($data['refund_status']) ? $data['refund_status'] : ''));
        if ($status === 'SUCCESS') {
            // 正常流程里已置 refunded，这里只做幂等确认
            return 'refunded';
        }

        if (in_array($status, ['ABNORMAL', 'CLOSED'], true)) {
            // 退款失败/关闭：把订单改回 paid，等待人工重试
            Db::transaction(function () use ($order, $status) {
                $locked = Db::name('fc_order')->where('id', (int)$order['id'])->lock(true)->find();
                if (!$locked || (string)$locked['status'] !== 'refunded') {
                    return;
                }
                Db::name('fc_order')->where('id', (int)$locked['id'])->update([
                    'status'        => 'paid',
                    'refund_amount' => 0,
                    'refund_reason' => '',
                    'updatetime'    => time(),
                ]);
                Db::name('fc_message')->insert([
                    'user_id'    => (int)$locked['user_id'],
                    'type'       => 'system',
                    'title'      => '退款异常',
                    'content'    => '您的订单「' . $locked['title'] . '」退款未成功（' . $status . '），客服将尽快处理。',
                    'isread'     => 0,
                    'createtime' => time(),
                ]);
            });
            Log::record('微信退款异常：订单 ' . $order['order_no'] . ' 状态 ' . $status, 'error');
            return 'failed';
        }

        return 'refunding';
    }

    /* ==================== 内部实现 ==================== */

    /** 生成退款单号（≤ 64 字符，全局唯一） */
    protected static function refundNo(array $order)
    {
        return 'RF' . (string)$order['order_no'] . bin2hex(random_bytes(2));
    }

    /**
     * 调用微信退款（V2/V3 参数不同，交给插件 SDK 处理签名）
     *
     * @throws \Exception
     */
    protected static function requestWechatRefund(array $order, $refundNo, $amount, $reason)
    {
        // 确保 epay 的 Yansongda 命名空间已注册（后台/CLI 场景下 action_begin 钩子可能未触发）
        if (!class_exists('\Yansongda\Pay\Pay')) {
            (new \addons\epay\Epay())->actionBegin();
        }

        $config = EpayService::getConfig('wechat', []);
        $pay = \Yansongda\Pay\Pay::wechat($config);

        $paidCents = (int)round((float)$order['amount'] * 100);
        $refundCents = (int)round($amount * 100);

        try {
            if (EpayService::isVersionV3()) {
                $result = $pay->refund([
                    'out_trade_no'  => (string)$order['order_no'],
                    'out_refund_no' => $refundNo,
                    'reason'        => mb_substr((string)$reason, 0, 80),
                    'amount'        => [
                        'refund'   => $refundCents,
                        'total'    => $paidCents,
                        'currency' => 'CNY',
                    ],
                ]);
            } else {
                $result = $pay->refund([
                    'out_trade_no'  => (string)$order['order_no'],
                    'out_refund_no' => $refundNo,
                    'total_fee'     => $paidCents,
                    'refund_fee'    => $refundCents,
                    'refund_desc'   => mb_substr((string)$reason, 0, 80),
                ]);
            }
        } catch (\Throwable $e) {
            Log::record('微信退款失败：订单 ' . $order['order_no'] . '，' . $e->getMessage(), 'error');
            throw new \Exception('微信退款失败：' . $e->getMessage());
        }

        $res = $result instanceof \Yansongda\Supports\Collection ? $result->all() : (array)$result;
        $status = isset($res['status']) ? (string)$res['status'] : '';
        // V3 受理成功返回 PROCESSING / SUCCESS；V2 返回 result_code=SUCCESS
        $ok = $status === 'SUCCESS' || $status === 'PROCESSING'
            || (isset($res['result_code']) && (string)$res['result_code'] === 'SUCCESS');
        if (!$ok) {
            $msg = isset($res['message']) ? (string)$res['message'] : (isset($res['err_code_des']) ? (string)$res['err_code_des'] : '未知错误');
            Log::record('微信退款未受理：订单 ' . $order['order_no'] . '，' . json_encode($res, JSON_UNESCAPED_UNICODE), 'error');
            throw new \Exception('微信退款未受理：' . $msg);
        }
    }

    /**
     * 退款后的权益回滚
     */
    protected static function rollbackBenefits(array $order, $amount, $now)
    {
        $type = (string)$order['type'];
        $userId = (int)$order['user_id'];

        if ($type === 'recharge') {
            // 扣回余额（前面已校验余额充足，这里用条件更新兜底防并发）
            $affected = Db::name('user')
                ->where('id', $userId)
                ->where('money', '>=', $amount)
                ->setDec('money', $amount);
            if (!$affected) {
                Log::record('退款回滚余额失败（余额不足）：订单 ' . $order['order_no'] . '，用户 ' . $userId, 'error');
            } else {
                $balance = round((float)Db::name('user')->where('id', $userId)->value('money'), 2);
                self::addFlow('expense', '充值退款', $amount, $balance, (int)$order['id'], '充值订单退款扣回', $userId);
                // 钱包流水（fa_user.money 减）→ 余额中心「余额明细」
                self::addWalletFlow($userId, 'expense', '充值退款', $amount, $balance, (int)$order['id'], '充值订单退款扣回');
            }
            return;
        }

        if ($type === 'payview') {
            Db::name('fc_pay_view')->where('order_id', (int)$order['id'])->delete();
            return;
        }

        if ($type === 'member') {
            self::revokeMembership($order, $now);
            return;
        }

        // post：信息保留，由运营决定是否下架
    }

    /**
     * 会员权益回滚：按该订单套餐的天数与赠送条数扣减（支持多次叠加购买）
     */
    protected static function revokeMembership(array $order, $now)
    {
        $userId = (int)$order['user_id'];
        $ext = Db::name('fc_user_ext')->where('user_id', $userId)->find();
        if (!$ext) {
            return;
        }

        $plan = null;
        if (!empty($order['related_id'])) {
            $plan = Db::name('fc_plan')->where('id', (int)$order['related_id'])->find();
        }
        $days = $plan ? max(0, (int)$plan['days']) : 0;
        $quota = $plan && isset($plan['post_quota']) ? max(0, (int)$plan['post_quota']) : 0;

        $currentExpire = (int)$ext['member_expiretime'];
        $expire = max($now, $currentExpire - $days * 86400);
        $left = max(0, (int)$ext['post_quota_left'] - $quota);

        $update = [
            'post_quota_left' => $left,
            'updatetime'      => $now,
        ];
        if ($expire <= $now) {
            $update['is_member'] = 0;
            $update['member_level'] = '';
            $update['member_expiretime'] = null;
            $update['post_quota_left'] = 0;
        } else {
            $update['member_expiretime'] = $expire;
        }

        Db::name('fc_user_ext')->where('user_id', $userId)->update($update);
    }

    /**
     * 冲销订单产生的分销佣金：已结算记录改为未结算（status=0），并通知分销员
     *
     * 已提现部分不回滚现金，但会体现在「可提现余额」中（可能为负，后续佣金先抵扣）。
     */
    protected static function reverseCommission(array $order, $now)
    {
        $orderNo = (string)$order['order_no'];
        if ($orderNo === '') {
            return;
        }

        $rows = Db::name('fc_commission')
            ->where('order_no', $orderNo)
            ->where('status', 'in', [0, 1])
            ->select();

        foreach ($rows as $row) {
            // status=2 表示已冲销（不计入累计/待结算/可提现）
            Db::name('fc_commission')->where('id', (int)$row['id'])->update([
                'status'     => 2,
                'settletime' => null,
            ]);

            Db::name('fc_message')->insert([
                'user_id'    => (int)$row['user_id'],
                'type'       => 'system',
                'title'      => '佣金已冲销',
                'content'    => '下线订单「' . $order['title'] . '」已退款，对应佣金 ' . $row['amount'] . ' 元已冲销。',
                'isread'     => 0,
                'createtime' => $now,
            ]);
        }
    }

    /** 资金流水 */
    protected static function addFlow($type, $scene, $amount, $balance, $relatedId, $remark, $userId = 0)
    {
        Db::name('fc_finance_flow')->insert([
            'user_id'    => (int)$userId,
            'flow_no'    => 'F' . date('YmdHis') . bin2hex(random_bytes(3)),
            'type'       => $type,
            'scene'      => $scene,
            'amount'     => $amount,
            'balance'    => $balance,
            'related_id' => (int)$relatedId,
            'remark'     => (string)$remark,
            'createtime' => time(),
        ]);
    }

    /** 用户钱包流水（fa_user.money 增减）→ 余额中心「余额明细」 */
    protected static function addWalletFlow($userId, $type, $scene, $amount, $balance, $relatedId, $remark)
    {
        Db::name('fc_wallet_flow')->insert([
            'user_id'    => (int)$userId,
            'flow_no'    => 'W' . date('YmdHis') . bin2hex(random_bytes(4)),
            'type'       => $type,
            'scene'      => $scene,
            'amount'     => $amount,
            'balance'    => $balance,
            'related_id' => (int)$relatedId,
            'remark'     => (string)$remark,
            'createtime' => time(),
        ]);
    }
}