Files
platform/web/services/coupon.go

65 lines
1.5 KiB
Go

package services
import (
"errors"
"fmt"
"platform/web/core"
m "platform/web/models"
q "platform/web/queries"
"time"
"github.com/shopspring/decimal"
"gorm.io/gorm"
)
var Coupon = &couponService{}
type couponService struct{}
func (s *couponService) GetCouponAvailableByCode(code string, amount decimal.Decimal, uid *int32) (*m.Coupon, error) {
// 获取优惠券
coupon, err := q.Coupon.Where(
q.Coupon.Code.Eq(code),
q.Coupon.Status.Eq(int(m.CouponStatusUnused)),
q.Coupon.
Where(q.Coupon.ExpireAt.Gt(time.Now())).
Or(q.Coupon.ExpireAt.IsNull()),
).Take()
if errors.Is(err, gorm.ErrRecordNotFound) {
return nil, core.NewBizErr("优惠券不存在或已失效")
}
if err != nil {
return nil, core.NewBizErr("获取优惠券数据失败", err)
}
// 检查最小使用额度
if amount.Cmp(coupon.MinAmount) < 0 {
return nil, core.NewBizErr(fmt.Sprintf("使用此优惠券的最小额度为 %s", coupon.MinAmount))
}
// 检查所属
if coupon.UserID != nil {
if uid == nil {
return nil, core.NewBizErr("检查优惠券所属用户失败")
}
if *coupon.UserID != *uid {
return nil, core.NewBizErr("优惠券不属于当前用户")
}
}
return coupon, nil
}
func (s *couponService) UseCoupon(q *q.Query, id int32) error {
_, err := q.Coupon.
Where(
q.Coupon.ID.Eq(id),
q.Coupon.Status.Eq(int(m.CouponStatusUnused)),
q.Coupon.ExpireAt.Gt(time.Now()),
).
UpdateSimple(
q.Coupon.Status.Value(int(m.CouponStatusUsed)),
)
return err
}