feat: implement coupon management and receive flow

backend/app/http/v1/user.go

@@ -1,6 +1,7 @@
 package v1
 
 import (
+	"quyun/v2/app/errorx"
 	"quyun/v2/app/http/v1/dto"
 	auth_dto "quyun/v2/app/http/v1/dto"
 	"quyun/v2/app/requests"
@@ -319,3 +320,40 @@ func (u *User) MyCoupons(ctx fiber.Ctx, user *models.User, status string) ([]dto
 	tenantID := getTenantID(ctx)
 	return services.Coupon.ListUserCoupons(ctx, tenantID, user.ID, status)
 }
+
+// List available coupons for order amount
+//
+// @Router /t/:tenantCode/v1/me/coupons/available [get]
+// @Summary List available coupons
+// @Description List coupons available for the given order amount
+// @Tags UserCenter
+// @Accept json
+// @Produce json
+// @Param amount query int64 true "Order amount (cents)"
+// @Success 200 {array} dto.UserCouponItem
+// @Bind user local key(__ctx_user)
+// @Bind amount query
+func (u *User) AvailableCoupons(ctx fiber.Ctx, user *models.User, amount int64) ([]dto.UserCouponItem, error) {
+	tenantID := getTenantID(ctx)
+	return services.Coupon.ListAvailable(ctx, tenantID, user.ID, amount)
+}
+
+// Receive coupon
+//
+// @Router /t/:tenantCode/v1/me/coupons/receive [post]
+// @Summary Receive coupon
+// @Description Receive a coupon by coupon_id
+// @Tags UserCenter
+// @Accept json
+// @Produce json
+// @Param form body dto.CouponReceiveForm true "Receive form"
+// @Success 200 {object} dto.UserCouponItem
+// @Bind user local key(__ctx_user)
+// @Bind form body
+func (u *User) ReceiveCoupon(ctx fiber.Ctx, user *models.User, form *dto.CouponReceiveForm) (*dto.UserCouponItem, error) {
+	tenantID := getTenantID(ctx)
+	if form == nil {
+		return nil, errorx.ErrInvalidParameter.WithMsg("参数无效")
+	}
+	return services.Coupon.Receive(ctx, tenantID, user.ID, form.CouponID)
+}