package service

import (
	"encoding/json"
	"errors"
	"strings"
	"time"

	"affiliate_dash/internal/model"
	"gorm.io/gorm"
)

type CreateTestOrderInput struct {
	MerchantID     uint
	ActorUserID    uint
	SKU            string
	BuyerReference string
	Note           string
	OrderStatus    string
}

// CreateTestOrder 创建后台联调订单：不扣钱包、不占库存，只用于上游按订单号查询与发货回传。
func (s *FulfillmentService) CreateTestOrder(in CreateTestOrderInput) (*model.FulfillmentOrder, error) {
	in.SKU = strings.TrimSpace(in.SKU)
	in.BuyerReference = strings.TrimSpace(in.BuyerReference)
	in.Note = strings.TrimSpace(in.Note)
	if in.MerchantID == 0 {
		return nil, errors.New("无效的商户")
	}
	if in.SKU == "" {
		return nil, errors.New("sku 不能为空")
	}
	if in.BuyerReference == "" {
		in.BuyerReference = "测试买家"
	}
	if len(in.BuyerReference) > 128 {
		return nil, errors.New("买家标识最长 128 位")
	}
	if len(in.Note) > 512 {
		return nil, errors.New("备注最长 512 位")
	}
	if in.OrderStatus == "" {
		in.OrderStatus = model.OrderStatusPaid
	}
	switch in.OrderStatus {
	case model.OrderStatusPaid, model.OrderStatusShipFailed, model.OrderStatusCancelled:
	default:
		return nil, errors.New("测试订单仅支持已支付待发货、发货失败或已取消状态")
	}

	requestData := map[string]interface{}{
		"source": "merchant_test_order",
	}
	if in.Note != "" {
		requestData["note"] = in.Note
	}
	rawRequestData, err := json.Marshal(requestData)
	if err != nil {
		return nil, errors.New("订单请求数据无法序列化")
	}
	var out model.FulfillmentOrder
	err = s.db.Transaction(func(tx *gorm.DB) error {
		var merchant model.Merchant
		if err := tx.Where("id = ? AND status = ?", in.MerchantID, model.MerchantStatusActive).First(&merchant).Error; err != nil {
			if errors.Is(err, gorm.ErrRecordNotFound) {
				return errors.New("商户不存在或已禁用")
			}
			return err
		}

		var product model.MerchantProduct
		if err := tx.Preload("Product").
			Where("merchant_id = ? AND sku = ? AND status = ?", in.MerchantID, in.SKU, model.ProductStatusActive).
			First(&product).Error; err != nil {
			if errors.Is(err, gorm.ErrRecordNotFound) {
				return errors.New("商品不存在或已下架")
			}
			return err
		}
		if product.Product == nil || product.Product.Status != model.ProductStatusActive {
			return errors.New("商品目录已下架")
		}

		orderNo := newTestFulfillmentOrderNo()
		order := &model.FulfillmentOrder{
			MerchantID:        in.MerchantID,
			OrderNo:           orderNo,
			ClientOrderNo:     "TEST-" + orderNo,
			MerchantProductID: product.ID,
			ProductSKU:        product.SKU,
			ProductName:       fallbackName(product.DisplayName, product.Product.Name),
			Quantity:          1,
			BaseAmount:        0,
			FeeType:           merchant.FeeType,
			FeeRateBP:         merchant.FeeRateBP,
			FeeFixedAmount:    merchant.FeeFixedAmount,
			ServiceFeeAmount:  0,
			Amount:            0,
			Currency:          product.Currency,
			OrderStatus:       in.OrderStatus,
			OrderSource:       model.OrderSourceTest,
			BuyerReference:    in.BuyerReference,
			RequestData:       string(rawRequestData),
		}
		if in.OrderStatus == model.OrderStatusShipFailed {
			order.FailureReason = fallbackName(in.Note, "联调测试订单初始化为发货失败，可重新发货")
		}
		if in.OrderStatus == model.OrderStatusCancelled {
			now := time.Now()
			order.CancelledAt = &now
		}
		if err := tx.Create(order).Error; err != nil {
			return err
		}
		canShip, _ := CanFulfill(order)
		if err := writeAudit(tx, &in.MerchantID, &in.ActorUserID, nil, "merchant_test_order.create", "fulfillment_order", order.OrderNo, map[string]interface{}{
			"sku":          in.SKU,
			"order_status": in.OrderStatus,
			"can_ship":     canShip,
		}); err != nil {
			return err
		}
		out = *order
		out.MerchantProduct = &product
		return nil
	})
	if err != nil {
		return nil, err
	}
	return &out, nil
}