package order

import (
	"context"

	"github.com/break/junhong_cmp_fiber/internal/model"
	"github.com/break/junhong_cmp_fiber/internal/model/dto"
	"github.com/break/junhong_cmp_fiber/pkg/constants"
	"github.com/break/junhong_cmp_fiber/pkg/errors"
)

// orderHasOnlinePaymentInfo 判断订单是否为 C 端在线购买且已支付或已退款，只有这类订单返回原始支付信息。
func orderHasOnlinePaymentInfo(order *model.Order) bool {
	if order == nil || order.BuyerType != model.BuyerTypePersonal {
		return false
	}
	if order.PaymentMethod != model.PaymentMethodWechat && order.PaymentMethod != model.PaymentMethodAlipay {
		return false
	}
	return order.PaymentStatus == model.PaymentStatusPaid || order.PaymentStatus == model.PaymentStatusRefunded
}

// orderIsOnlinePurchase 判断订单是否为个人客户微信或支付宝订单，详情支付单列表按此范围返回。
func orderIsOnlinePurchase(order *model.Order) bool {
	if order == nil || order.BuyerType != model.BuyerTypePersonal {
		return false
	}
	return order.PaymentMethod == model.PaymentMethodWechat || order.PaymentMethod == model.PaymentMethodAlipay
}

// fillOrderPaymentInfo 批量为订单响应填充交易流水号、支付渠道与商户名称；一次查询支付单、一次查询支付配置。
func (s *Service) fillOrderPaymentInfo(ctx context.Context, orders []*model.Order, responses []*dto.OrderResponse) error {
	orderIDs := make([]uint, 0, len(orders))
	for _, order := range orders {
		if orderHasOnlinePaymentInfo(order) {
			orderIDs = append(orderIDs, order.ID)
		}
	}
	if len(orderIDs) == 0 {
		return nil
	}
	var payments []*model.Payment
	// 带 order_type 过滤：tb_payment 同时存充值类支付，业务单 ID 空间与套餐订单不同。
	if err := s.db.WithContext(ctx).
		Where("order_id IN ? AND order_type = ? AND status = ?", orderIDs, model.PaymentOrderTypePackage, constants.PaymentRecordStatusPaid).
		Order("order_id ASC, paid_at DESC NULLS LAST, id DESC").
		Find(&payments).Error; err != nil {
		return errors.Wrap(errors.CodeDatabaseError, err, "查询订单支付记录失败")
	}
	channels, err := s.resolvePaymentChannels(ctx, payments)
	if err != nil {
		return err
	}
	paidByOrder := make(map[uint]*model.Payment, len(payments))
	for _, payment := range payments {
		if _, exists := paidByOrder[payment.OrderID]; !exists {
			paidByOrder[payment.OrderID] = payment
		}
	}
	for index, order := range orders {
		payment, ok := paidByOrder[order.ID]
		if !ok || !orderHasOnlinePaymentInfo(order) {
			continue
		}
		responses[index].ThirdPartyTradeNo = payment.ThirdPartyTradeNo
		responses[index].PaymentChannel = paymentChannel(payment, channels)
		responses[index].PaymentMerchantName = payment.MerchantNameSnapshot
	}
	return nil
}

// listOrderPayments 返回订单详情的全部支付单（任何状态），按创建时间倒序；不适用的订单返回空数组。
func (s *Service) listOrderPayments(ctx context.Context, order *model.Order) ([]*dto.OrderPaymentResponse, error) {
	result := make([]*dto.OrderPaymentResponse, 0)
	if !orderIsOnlinePurchase(order) {
		return result, nil
	}
	var payments []*model.Payment
	if err := s.db.WithContext(ctx).
		Where("order_id = ? AND order_type = ?", order.ID, model.PaymentOrderTypePackage).
		Order("created_at DESC, id DESC").
		Find(&payments).Error; err != nil {
		return nil, errors.Wrap(errors.CodeDatabaseError, err, "查询订单支付单失败")
	}
	channels, err := s.resolvePaymentChannels(ctx, payments)
	if err != nil {
		return nil, err
	}
	for _, payment := range payments {
		result = append(result, &dto.OrderPaymentResponse{
			PaymentNo:           payment.PaymentNo,
			PaymentMethod:       payment.PaymentMethod,
			PaymentChannel:      paymentChannel(payment, channels),
			PaymentMerchantName: payment.MerchantNameSnapshot,
			ThirdPartyTradeNo:   payment.ThirdPartyTradeNo,
			Amount:              payment.Amount,
			Status:              payment.Status,
			StatusName:          constants.GetPaymentRecordStatusName(payment.Status),
			CreatedAt:           payment.CreatedAt,
			PaidAt:              payment.PaidAt,
			ExpireAt:            payment.ExpireAt,
		})
	}
	return result, nil
}

// resolvePaymentChannels 为缺少渠道快照的历史支付单批量读取原支付配置的渠道类型（含已删除配置）。
func (s *Service) resolvePaymentChannels(ctx context.Context, payments []*model.Payment) (map[uint]string, error) {
	configIDs := make([]uint, 0)
	for _, payment := range payments {
		if payment.MerchantProviderTypeSnapshot == "" && payment.PaymentConfigID != nil {
			configIDs = append(configIDs, *payment.PaymentConfigID)
		}
	}
	channels := make(map[uint]string, len(configIDs))
	if len(configIDs) == 0 {
		return channels, nil
	}
	var configs []model.WechatConfig
	if err := s.db.WithContext(ctx).Unscoped().Select("id", "provider_type").
		Where("id IN ?", configIDs).Find(&configs).Error; err != nil {
		return nil, errors.Wrap(errors.CodeDatabaseError, err, "查询历史支付配置失败")
	}
	for _, config := range configs {
		channels[config.ID] = config.ProviderType
	}
	return channels, nil
}

// paymentChannel 取支付单渠道类型快照，没有快照时按原支付配置推断，推断不出为空串。
func paymentChannel(payment *model.Payment, channels map[uint]string) string {
	if payment.MerchantProviderTypeSnapshot != "" {
		return payment.MerchantProviderTypeSnapshot
	}
	if payment.PaymentConfigID == nil {
		return ""
	}
	return channels[*payment.PaymentConfigID]
}