<?php
namespace app\common\service;

use app\common\model\Order;
use app\common\model\PaymentTransaction;
use app\common\model\WechatMerchant;
use app\common\model\UserWechatIdentity;
use Illuminate\Database\Capsule\Manager as DB;

class PaymentService
{
    public static function createWechatJsapiPay(Order $order, string $appId, string $openid = ''): array
    {
        if ($order->status !== 'wait_pay') {
            throw new \RuntimeException('订单状态不正确');
        }

        $merchant = self::selectWechatMerchantForJsapi($order, $appId);
        if (!$merchant) {
            throw new \RuntimeException('未配置可用的微信商户号');
        }

        $notifyUrl = (string)($merchant->notify_url ?? '');
        if ($notifyUrl === '') {
            $notifyUrl = (string)(getenv('WECHATPAY_NOTIFY_URL') ?: '');
        }
        if ($notifyUrl === '') {
            throw new \RuntimeException('回调地址未配置');
        }

        $outTradeNo = self::genOutTradeNo($order);
        $amountFen = (int)round(((float)$order->total_price) * 100);
        $description = '安心验-鉴定订单 ' . $order->order_no;

        $openid = trim($openid);
        if ($openid === '') {
            $identity = UserWechatIdentity::where('user_id', $order->user_id)->where('app_id', $appId)->first();
            if ($identity) {
                $openid = (string)$identity->openid;
            }
        }
        if ($openid === '') {
            throw new \RuntimeException('缺少 openid，无法发起 JSAPI 支付');
        }

        DB::beginTransaction();
        try {
            $tx = PaymentTransaction::create([
                'order_id' => $order->id,
                'channel' => 'wechat',
                'merchant_id' => $merchant->id,
                'out_trade_no' => $outTradeNo,
                'amount' => $order->total_price,
                'status' => 'created',
            ]);

            $order->pay_channel = 'wechat';
            $order->pay_status = 'paying';
            $order->pay_merchant_id = $merchant->id;
            $order->pay_out_trade_no = $outTradeNo;
            $order->save();

            $client = new WechatPayV3Client($merchant);
            $resp = $client->createJsapiTransaction($outTradeNo, $description, $amountFen, $notifyUrl, $openid);

            $tx->prepay_id = $resp['prepay_id'] ?? null;
            $tx->raw_json = $resp;
            $tx->save();

            if (!$tx->prepay_id) {
                throw new \RuntimeException('微信支付下单失败：缺少 prepay_id');
            }

            $payParams = $client->buildJsapiPayParams($appId, $tx->prepay_id);

            DB::commit();

            return [
                'channel' => 'wechat',
                'pay_type' => 'jsapi',
                'out_trade_no' => $outTradeNo,
                'merchant' => [
                    'id' => $merchant->id,
                    'name' => $merchant->name,
                    'mode' => $merchant->mode,
                    'mch_id' => $merchant->mch_id,
                ],
                'pay_params' => $payParams,
            ];
        } catch (\Throwable $e) {
            DB::rollBack();
            throw $e;
        }
    }

    public static function createWechatNativePay(Order $order): array
    {
        if ($order->status !== 'wait_pay') {
            throw new \RuntimeException('订单状态不正确');
        }

        $merchant = self::selectWechatMerchant($order);
        if (!$merchant) {
            throw new \RuntimeException('未配置可用的微信商户号');
        }

        $notifyUrl = (string)($merchant->notify_url ?? '');
        if ($notifyUrl === '') {
            $notifyUrl = (string)(getenv('WECHATPAY_NOTIFY_URL') ?: '');
        }
        if ($notifyUrl === '') {
            throw new \RuntimeException('回调地址未配置');
        }

        $outTradeNo = self::genOutTradeNo($order);
        $amountFen = (int)round(((float)$order->total_price) * 100);
        $description = '安心验-鉴定订单 ' . $order->order_no;

        DB::beginTransaction();
        try {
            $tx = PaymentTransaction::create([
                'order_id' => $order->id,
                'channel' => 'wechat',
                'merchant_id' => $merchant->id,
                'out_trade_no' => $outTradeNo,
                'amount' => $order->total_price,
                'status' => 'created',
            ]);

            $order->pay_channel = 'wechat';
            $order->pay_status = 'paying';
            $order->pay_merchant_id = $merchant->id;
            $order->pay_out_trade_no = $outTradeNo;
            $order->save();

            $client = new WechatPayV3Client($merchant);
            $resp = $client->createNativeTransaction($outTradeNo, $description, $amountFen, $notifyUrl);

            $tx->prepay_id = $resp['prepay_id'] ?? null;
            $tx->code_url = $resp['code_url'] ?? null;
            $tx->raw_json = $resp;
            $tx->save();

            DB::commit();

            return [
                'channel' => 'wechat',
                'pay_type' => 'native',
                'out_trade_no' => $outTradeNo,
                'code_url' => $tx->code_url,
                'merchant' => [
                    'id' => $merchant->id,
                    'name' => $merchant->name,
                    'mode' => $merchant->mode,
                    'mch_id' => $merchant->mch_id,
                ],
            ];
        } catch (\Throwable $e) {
            DB::rollBack();
            throw $e;
        }
    }

    public static function selectWechatMerchant(Order $order): ?WechatMerchant
    {
        $list = WechatMerchant::where('status', 1)
            ->whereIn('mode', ['direct', 'service_provider'])
            ->whereNotNull('serial_no')->where('serial_no', '<>', '')
            ->whereNotNull('api_v3_key')->where('api_v3_key', '<>', '')
            ->where(function ($q) {
                $q->where(function ($q2) {
                    $q2->whereNotNull('private_key_pem')->where('private_key_pem', '<>', '');
                })->orWhere(function ($q2) {
                    $q2->whereNotNull('apiclient_key_path')->where('apiclient_key_path', '<>', '');
                });
            })
            ->orderByDesc('is_default')
            ->orderBy('id')
            ->get();
        if ($list->count() === 0) return null;
        if ($list->count() === 1) return $list->first();

        $default = $list->firstWhere('is_default', 1);
        if ($default) return $default;

        $idx = abs(crc32((string)$order->order_no)) % $list->count();
        return $list->values()->get($idx);
    }

    public static function selectWechatMerchantForJsapi(Order $order, string $appId): ?WechatMerchant
    {
        $appId = trim($appId);
        if ($appId === '') {
            throw new \RuntimeException('缺少 app_id');
        }

        $list = WechatMerchant::where('status', 1)
            ->whereIn('mode', ['direct', 'service_provider'])
            ->whereNotNull('serial_no')->where('serial_no', '<>', '')
            ->whereNotNull('api_v3_key')->where('api_v3_key', '<>', '')
            ->where(function ($q) {
                $q->where(function ($q2) {
                    $q2->whereNotNull('private_key_pem')->where('private_key_pem', '<>', '');
                })->orWhere(function ($q2) {
                    $q2->whereNotNull('apiclient_key_path')->where('apiclient_key_path', '<>', '');
                });
            })
            ->get()
            ->filter(function ($m) use ($appId) {
                $mode = (string)($m->mode ?? '');
                if ($mode === 'direct') {
                    return (string)($m->app_id ?? '') === $appId;
                }
                if ($mode === 'service_provider') {
                    $subAppId = (string)($m->sub_app_id ?? '');
                    if ($subAppId !== '') return $subAppId === $appId;
                    return (string)($m->app_id ?? '') === $appId;
                }
                return false;
            })
            ->values();

        if ($list->count() === 0) return null;
        if ($list->count() === 1) return $list->first();

        $default = $list->firstWhere('is_default', 1);
        if ($default) return $default;

        $idx = abs(crc32((string)$order->order_no)) % $list->count();
        return $list->get($idx);
    }

    private static function genOutTradeNo(Order $order): string
    {
        return 'AXY' . date('YmdHis') . $order->id . random_int(1000, 9999);
    }

    private static function resolveJsapiAppId(WechatMerchant $merchant): string
    {
        $mode = (string)($merchant->mode ?? 'direct');
        $appId = (string)($merchant->app_id ?? '');
        $subAppId = (string)($merchant->sub_app_id ?? '');

        if ($mode === 'direct') {
            if ($appId === '') throw new \RuntimeException('商户 AppID 未配置');
            return $appId;
        }
        if ($mode === 'service_provider') {
            if ($subAppId !== '') return $subAppId;
            if ($appId === '') throw new \RuntimeException('服务商 AppID 未配置');
            return $appId;
        }
        throw new \RuntimeException('该商户类型暂不支持 JSAPI');
    }
}