<?php

namespace App\Services;

use App\Exceptions\RepositoryException;
use App\Models\BillModel;
use App\Models\NoticeModel;
use App\Models\PaymentModel;
use App\Models\StoreModel;
use Illuminate\Support\Carbon;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;
use Throwable;

/**
 * 在线支付编排服务（渠道二选一：旺铺网关 / 微信官方支付）
 *
 * 链路：门店小程序选择账单合并付款
 *   → code2session 换 openid → 校验并锁定账单 → 创建支付单（pay_type=2）
 *   → 按当前渠道（site_config pay.online_channel）走旺铺统一下单或微信 JSAPI 下单
 *   → 返回调起支付参数 → 小程序 wx.requestPayment
 *   → 网关后台通知 / 小程序主动查询 → settle() 幂等结账：
 *   支付单置成功 + 关联账单批量置已支付 + 累加门店总采购金额（只统计商品金额）+ 通知门店
 *
 * 已创建的支付单按自身 pay_method 固定在原渠道查询/结账（渠道切换不影响进行中的支付单）。
 * 结账口径与后台「支付审核通过 / 线下收款登记」保持一致。
 */
class OnlinePaymentService
{
    /** 在线支付渠道：旺铺支付网关 */
    public const string CHANNEL_WANGPU = 'wangpu';
    /** 在线支付渠道：微信官方支付 */
    public const string CHANNEL_WECHAT = 'wechat';

    /** 支付场景：微信小程序（wx.login 换 openid，wx.requestPayment 调起） */
    public const string SCENE_MINI = 'mini';
    /** 支付场景：公众号 H5（网页授权换 openid，WeixinJSBridge 调起） */
    public const string SCENE_MP = 'mp';

    public function __construct(
        protected BillNumberService $billNumber,
        protected WangpuPayService $wangpu,
        protected WechatPayService $wxpay,
        protected WechatMiniService $wechat,
        protected WechatMpService $wechatMp,
    ) {}

    /**
     * 当前在线支付渠道（site_config pay.online_channel 优先，回退 env PAY_ONLINE_CHANNEL，默认旺铺）
     */
    public function channel(): string
    {
        $channel = (string) site_config('pay.online_channel', '');
        if ($channel === '') {
            $channel = (string) config('services.pay.online_channel', self::CHANNEL_WANGPU);
        }
        return $channel === self::CHANNEL_WECHAT ? self::CHANNEL_WECHAT : self::CHANNEL_WANGPU;
    }

    /**
     * 发起在线支付
     *
     * @param array<int, int> $billIds 合并付款的账单ID
     * @param string $code 小程序 wx.login() 登录凭证 / 公众号网页授权 code（按 scene 区分）
     * @param string $scene 支付场景：mini=小程序（默认） / mp=公众号 H5
     * @return array{0: PaymentModel, 1: array<string, mixed>} 支付单与渠道返回的调起支付参数
     * @throws Throwable
     */
    public function create(StoreModel $store, array $billIds, string $code, string $remark = '', string $scene = self::SCENE_MINI): array
    {
        $channel = $this->channel();
        $payMethod = $channel === self::CHANNEL_WECHAT ? PaymentModel::METHOD_WECHAT : PaymentModel::METHOD_WANGPU;

        // 换取付款人 openid 并绑定到门店（小程序/公众号分场景绑定，两者 openid 维度不同不可混用）
        if ($scene === self::SCENE_MP) {
            $openid = $this->wechatMp->code2openid($code);
            if ((string) $store->mp_openid !== $openid) {
                $store->mp_openid = $openid;
                $store->save();
            }
        } else {
            $openid = $this->wechat->code2session($code);
            if ((string) $store->openid !== $openid) {
                $store->openid = $openid;
                $store->save();
            }
        }

        [$payment, $bills] = DB::transaction(function () use ($store, $billIds, $openid, $remark, $payMethod) {
            $bills = BillModel::query()
                ->where('store_id', $store->id)
                ->whereIn('id', $billIds)
                ->lockForUpdate()
                ->get();
            if ($bills->count() !== count($billIds)) {
                throw new RepositoryException('包含不属于本店的账单，请刷新后重试');
            }
            foreach ($bills as $bill) {
                if ($bill->status === BillModel::STATUS_PAID) {
                    throw new RepositoryException('账单 ' . $bill->bill_no . ' 已支付，请刷新后重试');
                }
                if ((int) $bill->payment_id !== 0) {
                    throw new RepositoryException('账单 ' . $bill->bill_no . ' 正在支付中，请勿重复提交');
                }
            }

            $amount = $bills->reduce(
                static fn (string $carry, BillModel $bill): string => bcadd($carry, (string) $bill->total_amount, 2),
                '0'
            );
            if (bccomp($amount, '0', 2) <= 0) {
                throw new RepositoryException('支付金额必须大于 0');
            }

            $payment = PaymentModel::create([
                'payment_no' => $this->billNumber->make('ZF'),
                'store_id' => $store->id,
                'amount' => $amount,
                'pay_type' => PaymentModel::TYPE_ONLINE,
                'pay_method' => $payMethod,
                'voucher_ids' => '',
                'status' => PaymentModel::STATUS_PENDING,
                'openid' => $openid,
                'remark' => $remark,
            ]);

            // 锁定账单到本支付记录（支付失败/取消后释放，可重新付款）
            BillModel::query()->whereIn('id', $bills->pluck('id'))->update(['payment_id' => $payment->id]);

            return [$payment, $bills];
        });

        try {
            $gatewayData = $channel === self::CHANNEL_WECHAT
                ? $this->wxpay->createOrder(
                    $payment->payment_no,
                    (string) $payment->amount,
                    $openid,
                    '账单合并付款-' . $payment->payment_no,
                    $scene === self::SCENE_MP ? $this->wechatMp->appid() : '',
                )
                : $this->wangpu->createOrder([
                    'mer_order_id' => $payment->payment_no,
                    'order_amt' => (string) $payment->amount,
                    'open_id' => $openid,
                    'sub_appid' => $this->subAppid($scene),
                    'payway_code' => $this->wangpu->paywayCode($scene),
                    'order_title' => '账单合并付款-' . $payment->payment_no,
                    'notifyurl' => $this->wangpu->notifyUrl(),
                ]);
        } catch (Throwable $e) {
            // 网关下单失败：整笔作废并释放账单，门店可重新发起
            $this->discard($payment, $e->getMessage());
            throw $e;
        }

        if ($channel === self::CHANNEL_WANGPU) {
            $payment->order_id = (string) ($gatewayData['order_id'] ?? '');
        }
        $payment->pay_params = $gatewayData;
        $payment->save();

        // 调起支付参数：旺铺渠道在应答 wxjsapistr（JSON 串）中；微信渠道下单应答本身即调起参数
        $wxjsapiData = $channel === self::CHANNEL_WANGPU
            ? json_decode((string) ($gatewayData['wxjsapistr'] ?? '{}'))
            : $gatewayData;

        return [$payment, $wxjsapiData];
    }

    /**
     * 旺铺支付成功后台通知处理：验签由控制器完成，此处按 mer_order_id 定位支付单并幂等结账
     *
     * @param array<string, mixed> $params 通知报文（已验签）
     * @return bool 本次是否执行了结账（false = 重复通知）
     * @throws Throwable
     */
    public function settleByNotify(array $params): bool
    {
        $merOrderId = (string) ($params['mer_order_id'] ?? '');
        $payment = PaymentModel::query()
            ->where('payment_no', $merOrderId)
            ->where('pay_type', PaymentModel::TYPE_ONLINE)
            ->first();
        if ($payment === null) {
            throw new RepositoryException('支付记录不存在：' . $merOrderId);
        }
        if ((int) ($params['order_status'] ?? -1) !== WangpuPayService::ORDER_STATUS_PAID) {
            throw new RepositoryException('订单未支付成功（order_status=' . ($params['order_status'] ?? '空') . '）');
        }

        return $this->settle(
            $payment,
            (string) ($params['trade_no'] ?? ''),
            (string) ($params['order_id'] ?? ''),
            (string) ($params['trade_time'] ?? ''),
            (string) ($params['order_amt'] ?? '0'),
        );
    }

    /**
     * 微信支付成功后台通知处理：验签/解密由 WechatPayService 完成，此处按 out_trade_no 定位支付单并幂等结账
     *
     * @param array<string, mixed> $params 解密后的交易报文（out_trade_no/trade_state/transaction_id/success_time/amount）
     * @return bool 本次是否执行了结账（false = 重复通知）
     * @throws Throwable
     */
    public function settleByWechatNotify(array $params): bool
    {
        $outTradeNo = (string) ($params['out_trade_no'] ?? '');
        $payment = PaymentModel::query()
            ->where('payment_no', $outTradeNo)
            ->where('pay_type', PaymentModel::TYPE_ONLINE)
            ->first();
        if ($payment === null) {
            throw new RepositoryException('支付记录不存在：' . $outTradeNo);
        }
        if (($params['trade_state'] ?? '') !== WechatPayService::TRADE_STATE_SUCCESS) {
            throw new RepositoryException('订单未支付成功（trade_state=' . ($params['trade_state'] ?? '空') . '）');
        }
        // 商户号一致性校验，防串号
        $mchId = (string) ($params['mchid'] ?? '');
        if ($mchId !== '' && $mchId !== $this->wxpayMchId()) {
            throw new RepositoryException('通知商户号与配置不一致');
        }

        return $this->settle(
            $payment,
            (string) ($params['transaction_id'] ?? ''),
            '',
            (string) ($params['success_time'] ?? ''),
            bcdiv((string) (int) ($params['amount']['total'] ?? 0), '100', 2),
        );
    }

    /**
     * 主动查询渠道订单状态：已支付则结账（回调延迟/丢失时的兜底，小程序支付完成后调用）
     *
     * 按支付单的 pay_method 固定在原渠道查询，渠道切换不影响进行中的支付单
     *
     * @return array{payment: PaymentModel, order_status: int} 最新支付单与渠道订单状态（1=已支付）
     * @throws Throwable
     */
    public function queryAndSettle(PaymentModel $payment): array
    {
        if ($payment->status === PaymentModel::STATUS_APPROVED) {
            return ['payment' => $payment, 'order_status' => WangpuPayService::ORDER_STATUS_PAID];
        }

        if ($payment->pay_method === PaymentModel::METHOD_WECHAT) {
            return $this->queryWechatAndSettle($payment);
        }

        $data = $this->wangpu->queryOrder($payment->payment_no, (string) $payment->order_id);
        $orderStatus = (int) ($data['order_status'] ?? -1);

        if ($orderStatus === WangpuPayService::ORDER_STATUS_PAID) {
            $this->settle(
                $payment,
                (string) ($data['trade_no'] ?? ''),
                (string) ($data['order_id'] ?? ''),
                (string) ($data['trade_time'] ?? ''),
                (string) ($data['order_amt'] ?? '0'),
            );
        }

        return ['payment' => $payment->fresh(), 'order_status' => $orderStatus];
    }

    /**
     * 微信渠道主动查询：trade_state=SUCCESS 则结账
     *
     * @return array{payment: PaymentModel, order_status: int}
     * @throws Throwable
     */
    protected function queryWechatAndSettle(PaymentModel $payment): array
    {
        $data = $this->wxpay->queryOrder($payment->payment_no);
        $paid = ($data['trade_state'] ?? '') === WechatPayService::TRADE_STATE_SUCCESS;

        if ($paid) {
            $this->settle(
                $payment,
                (string) ($data['transaction_id'] ?? ''),
                '',
                (string) ($data['success_time'] ?? ''),
                bcdiv((string) (int) ($data['amount']['total'] ?? 0), '100', 2),
            );
        }

        return ['payment' => $payment->fresh(), 'order_status' => $paid ? 1 : 0];
    }

    /**
     * 幂等结账（网关通知与主动查询共用入口，内部事务 + 行锁防重）
     *
     * @return bool 本次是否执行了结账（false = 已结账，直接吞掉重复通知）
     * @throws Throwable
     */
    public function settle(PaymentModel $payment, string $tradeNo, string $orderId, string $tradeTime, string $paidAmount): bool
    {
        $settled = DB::transaction(function () use ($payment, $tradeNo, $orderId, $tradeTime, $paidAmount) {
            $payment = PaymentModel::query()->lockForUpdate()->find($payment->id);
            if ($payment === null) {
                throw new RepositoryException('支付记录不存在');
            }
            if ($payment->status === PaymentModel::STATUS_APPROVED) {
                return false; // 幂等：重复通知/查询直接成功
            }
            if ($payment->pay_type !== PaymentModel::TYPE_ONLINE || $payment->status !== PaymentModel::STATUS_PENDING) {
                throw new RepositoryException('支付记录状态异常，无法结账');
            }
            // 金额一致性校验，防通知篡改
            if (bccomp($paidAmount, (string) $payment->amount, 2) !== 0) {
                throw new RepositoryException('支付金额与订单金额不一致（通知 ' . $paidAmount . ' / 订单 ' . $payment->amount . '）');
            }

            $bills = $payment->bills()->lockForUpdate()->get();
            // 任一账单已通过其他方式收款（如线下登记）则中止，避免重复收款，需人工核实
            $paid = $bills->where('status', BillModel::STATUS_PAID);
            if ($paid->isNotEmpty()) {
                throw new RepositoryException('账单 ' . $paid->pluck('bill_no')->implode('、') . ' 已通过其他方式收款，请人工核实');
            }

            $paidAt = $this->parseTradeTime($tradeTime);
            BillModel::query()->whereIn('id', $bills->pluck('id'))->update([
                'status' => BillModel::STATUS_PAID,
                'paid_at' => $paidAt,
                'paid_operator_id' => 0,
                'pay_remark' => (PaymentModel::METHOD_NAMES[$payment->pay_method] ?? '在线支付') . '（支付单号 ' . $payment->payment_no . '）',
            ]);

            // 按门店累加总采购金额（只统计商品金额，不含配送费/附加金额）
            $store = StoreModel::query()->lockForUpdate()->find($payment->store_id);
            if ($store !== null) {
                $amount = '0';
                foreach ($bills as $bill) {
                    $amount = bcadd($amount, (string) $bill->product_amount, 2);
                }
                $store->total_purchase_amount = bcadd((string) $store->total_purchase_amount, $amount, 2);
                $store->save();
            }

            $payment->status = PaymentModel::STATUS_APPROVED;
            $payment->trade_no = $tradeNo;
            if ($orderId !== '') {
                $payment->order_id = $orderId;
            }
            $payment->paid_at = $paidAt;
            $payment->save();

            return true;
        });

        if ($settled) {
            $this->notifyStore($payment->fresh());
        }

        return $settled;
    }

    /**
     * 网关下单失败后作废支付单：置失败并释放账单（保留记录便于排查）
     */
    protected function discard(PaymentModel $payment, string $reason): void
    {
        try {
            DB::transaction(function () use ($payment, $reason) {
                BillModel::query()
                    ->where('payment_id', $payment->id)
                    ->where('status', BillModel::STATUS_UNPAID)
                    ->update(['payment_id' => 0]);
                PaymentModel::query()->where('id', $payment->id)->update([
                    'status' => PaymentModel::STATUS_REJECTED,
                    'audit_remark' => mb_substr('网关下单失败：' . $reason, 0, 255),
                ]);
            });
        } catch (Throwable $e) {
            Log::error('在线支付作废失败', ['payment_id' => $payment->id, 'error' => $e->getMessage()]);
        }
    }

    /**
     * 结账成功后通知门店
     */
    protected function notifyStore(PaymentModel $payment): void
    {
        try {
            $billsCount = $payment->bills()->count();
            NoticeModel::create([
                'store_id' => $payment->store_id,
                'type' => NoticeModel::TYPE_SYSTEM,
                'title' => '账单支付成功',
                'content' => mb_substr("您的 {$billsCount} 张账单已通过在线支付完成付款，金额 {$payment->amount} 元（支付单号 {$payment->payment_no}）", 0, 500),
                'data' => ['payment_id' => $payment->id],
                'is_read' => NoticeModel::UNREAD,
            ]);
        } catch (Throwable $e) {
            Log::warning('支付成功通知门店失败', ['payment_id' => $payment->id, 'error' => $e->getMessage()]);
        }
    }

    /**
     * 网关交易时间解析（格式 yyyy-MM-dd HH:mm:ss，异常回退当前时间）
     */
    protected function parseTradeTime(string $tradeTime): Carbon
    {
        try {
            return $tradeTime !== '' ? Carbon::parse($tradeTime) : now();
        } catch (Throwable) {
            return now();
        }
    }

    /**
     * 下单微信子 appid（默认取小程序 appid；公众号 H5 场景取公众号 appid）
     */
    protected function subAppid(string $scene = self::SCENE_MINI): string
    {
        if ($scene === self::SCENE_MP) {
            return $this->wechatMp->appid();
        }
        $subAppid = (string) site_config('wangpu.sub_appid', '');
        if ($subAppid === '') {
            $subAppid = (string) config('services.wangpu.sub_appid', '');
        }
        if ($subAppid === '') {
            $subAppid = $this->wechat->appid();
        }
        return trim($subAppid);
    }

    /**
     * 微信渠道商户号（用于通知商户号一致性校验）
     */
    protected function wxpayMchId(): string
    {
        $mchId = (string) site_config('wxpay.mch_id', '');
        if ($mchId === '') {
            $mchId = (string) config('services.wxpay.mch_id', '');
        }
        return trim($mchId);
    }
}