<?php

namespace App\Services;

use App\Enums\OfflineOrderStatus;
use App\Enums\PayWay;
use App\Enums\PointLogAction;
use App\Enums\SocialiteType;
use App\Enums\WxpayTradeType;
use App\Exceptions\BizException;
use App\Models\OfflineOrder;
use App\Models\OfflineOrderItem;
use App\Models\OfflineOrderPreview;
use App\Models\OfflineProductCategory;
use App\Models\SocialiteUser;
use App\Models\User;
use App\Services\Payment\WxpayService;


class OfflineOrderService
{
    public function create(User $user, OfflineOrderPreview $orderPreview, int $points = 0): OfflineOrder
    {
        $items = $this->mapItems($orderPreview->payload['items']);

        [
            $productsTotalAmount,
            $discountReductionAmount,
            $paymentAmount,
        ] = $this->calculateFees($items);

        // 积分抵扣金额
        $pointsDeductionAmount = $points;

        $paymentAmount -= $pointsDeductionAmount;
        if ($paymentAmount < 0) {
            $paymentAmount = 0;
        }

        do {
            $sn = serial_number();
        } while(OfflineOrder::where('sn', $sn)->exists());

        /** @var \App\Models\OfflineOrder */
        $order = OfflineOrder::create([
            'user_id' => $user->id,
            'store_id' => $orderPreview->store_id,
            'staff_id' => $orderPreview->staff_id,
            'sn' => $sn,
            'products_total_amount' => $productsTotalAmount,
            'discount_reduction_amount' => $discountReductionAmount,
            'points_deduction_amount' => $pointsDeductionAmount,
            'payment_amount' => $paymentAmount,
            'status' => OfflineOrderStatus::Pending,
            'orderable_type' => $orderPreview->getMorphClass(),
            'orderable_id' => $orderPreview->id,
        ]);

        $this->insertOrderItems($order, $items);

        // 扣除积分
        if ($points > 0) {
            (new PointService)->change($user, -$points, PointLogAction::Consumption, "线下订单{$order->sn}使用积分", $order);
        }

        if ($order->payment_amount === 0) {
            $this->pay($order, PayWay::None);

            $order->refresh();
        }

        return $order;
    }

    public function check(User $user, array $items): array
    {
        $productCategoryIds = collect($items)->pluck('product_category_id');

        $productCategories = OfflineProductCategory::query()
            ->whereIn('id',  $productCategoryIds->all())
            ->get()
            ->keyBy('id');

        if ($productCategories->count() != $productCategoryIds->count()) {
            throw new BizException('商品分类异常');
        }

        $mapItems = $this->mapItems($items);

        [
            $productsTotalAmount,
            $discountReductionAmount,
            $paymentAmount,
        ] = $this->calculateFees($mapItems);

        //---------------------------------------
        // 积分当钱花
        //---------------------------------------
        $remainingPoints = $user->userInfo->points; // 用户剩余积分
        $availablePoints = $paymentAmount > $remainingPoints ? $remainingPoints : $paymentAmount; // 可用积分

        return [
            'items' => collect($mapItems)->map(fn($item) => [
                'product_category' => $productCategories->get($item['product_category_id']),
                'discount_reduction_amount' => bcdiv($item['discount_reduction_amount'], 100, 2),
                'products_total_amount' => bcdiv($item['products_total_amount'], 100, 2),
                'payment_amount' => bcdiv($item['payment_amount'], 100, 2),
            ]),
            'products_total_amount' => bcdiv($productsTotalAmount, 100, 2),
            'discount_reduction_amount' => bcdiv($discountReductionAmount, 100, 2),
            'payment_amount' => bcdiv($paymentAmount, 100, 2),
            'remaining_points' => bcdiv($remainingPoints, 100, 2), // 剩余积分
            'available_points' => bcdiv($availablePoints, 100, 2), // 可用积分
            'points_discount_amount' => bcdiv($availablePoints, 100, 2), // 积分抵扣金额
        ];
    }

    public function pay(OfflineOrder $order, PayWay $payWay)
    {
        if (! $order->isPending()) {
            throw new BizException('订单状态不是待付款');
        }

        $payLog = $order->payLogs()->create([
            'pay_way' => $payWay,
        ]);

        $data = null;

        if ($order->payment_amount === 0) {
            (new PayService())->handleSuccess($payLog, [
                'pay_at' => now(),
            ]);
        } elseif ($payLog->isWxpay()) {
            if (is_null($tradeType = WxpayTradeType::tryFromPayWay($payLog->pay_way))) {
                throw new BizException('支付方式 非法');
            }
            $params = [
                'body' => app_settings('app.app_name').'-线下订单',
                'out_trade_no' => $payLog->pay_sn,
                'total_fee' => $order->payment_amount,
                'trade_type' => $tradeType->value,
            ];

            if ($payLog->pay_way === PayWay::WxpayMiniProgram) {
                $socialite = SocialiteUser::where([
                    'user_id' => $order->user_id,
                    'socialite_type' => SocialiteType::WechatMiniProgram,
                ])->first();

                if ($socialite === null) {
                    throw new BizException('未绑定微信小程序');
                }

                $params['openid'] = $socialite->socialite_id;
            }

            $data = (new WxpayService())->pay($params, match ($payLog->pay_way) {
                PayWay::WxpayMiniProgram => 'mini_program',
                default => 'default',
            });
        }

        return [
            'pay_way' => $payLog->pay_way,
            'data' => $data,
        ];
    }

    protected function insertOrderItems(OfflineOrder $order, array $items)
    {
        $remainingPointDiscountAmount = $order->points_deduction_amount;

        OfflineOrderItem::insert(
            collect($items)->map(function ($item) use ($order, &$remainingPointDiscountAmount) {
                $pointsDeductionAmount = $item['payment_amount'];
                if ($item['payment_amount'] > $remainingPointDiscountAmount) {
                    $pointsDeductionAmount = $remainingPointDiscountAmount;
                }
                $remainingPointDiscountAmount -= $pointsDeductionAmount;

                return [
                    'order_id' => $order->id,
                    'product_category_id' => $item['product_category_id'],
                    'products_total_amount' => $item['products_total_amount'],
                    'discount_reduction_amount' => $item['discount_reduction_amount'],
                    'points_deduction_amount' => $pointsDeductionAmount,
                    'payment_amount' => $item['payment_amount'] - $pointsDeductionAmount,
                    'created_at' => $order->created_at,
                    'updated_at' => $order->updated_at,
                ];
            })->all()
        );
    }

    protected function mapItems(array $items): array
    {
        return collect($items)->map(function ($item) {
            $productsTotalAmount = bcmul($item['products_total_amount'], 100);
            if ($productsTotalAmount < 0) {
                throw new BizException('商品总额不能小于0');
            }

            $paymentAmount = $productsTotalAmount;
            if (is_numeric($item['discount'])) {
                if ($item['discount'] <= 0) {
                    throw new BizException('折扣必须大于0');
                } elseif ($item['discount'] >= 10) {
                    throw new BizException('折扣必须小于10');
                }
                $discount = bcdiv($item['discount'], 10, 3);
                $paymentAmount = round(bcmul($productsTotalAmount, $discount, 2));
            }

            return [
                'product_category_id' => $item['product_category_id'],
                'products_total_amount' => (int) $productsTotalAmount,
                'discount_reduction_amount' => (int) ($productsTotalAmount - $paymentAmount),
                'payment_amount' => (int) $paymentAmount,
            ];
        })->all();
    }

    protected function calculateFees(array $items)
    {
        $totalProductsTotalAmount = 0;
        $totalDiscountReductionAmount = 0;
        $totalPaymentAmount = 0;

        foreach ($items as $item) {
            $totalProductsTotalAmount += $item['products_total_amount'];
            $totalDiscountReductionAmount += $item['discount_reduction_amount'];
            $totalPaymentAmount += $item['payment_amount'];
        }

        return [$totalProductsTotalAmount, $totalDiscountReductionAmount, $totalPaymentAmount];
    }
}