feat: implement coupon management and receive flow

backend/app/services/coupon_test.go

@@ -58,7 +58,7 @@ func (s *CouponTestSuite) Test_CouponFlow() {
 		cp := &models.Coupon{
 			TenantID:       tenantID,
 			Title:          "Save 5",
-			Type:           "fix_amount",
+			Type:           consts.CouponTypeFixAmount,
 			Value:          500,
 			MinOrderAmount: 1000,
 		}
@@ -68,7 +68,7 @@ func (s *CouponTestSuite) Test_CouponFlow() {
 		uc := &models.UserCoupon{
 			UserID:   user.ID,
 			CouponID: cp.ID,
-			Status:   "unused",
+			Status:   consts.UserCouponStatusUnused,
 		}
 		models.UserCouponQuery.WithContext(ctx).Create(uc)
 
@@ -91,7 +91,7 @@ func (s *CouponTestSuite) Test_CouponFlow() {
 				TenantID:    tenantID,
 				ContentID:   c.ID,
 				PriceAmount: 2000, // 20.00 CNY
-				Currency:    "CNY",
+				Currency:    consts.CurrencyCNY,
 			})
 
 			form := &order_dto.OrderCreateForm{
@@ -112,8 +112,87 @@ func (s *CouponTestSuite) Test_CouponFlow() {
 
 			// Verify Coupon Status
 			ucReload, _ := models.UserCouponQuery.WithContext(ctx).Where(models.UserCouponQuery.ID.Eq(uc.ID)).First()
-			So(ucReload.Status, ShouldEqual, "used")
+			So(ucReload.Status, ShouldEqual, consts.UserCouponStatusUsed)
 			So(ucReload.OrderID, ShouldEqual, oid)
 		})
 	})
 }
+
+func (s *CouponTestSuite) Test_Receive() {
+	Convey("Receive", s.T(), func() {
+		ctx := s.T().Context()
+		tenantID := int64(2)
+		database.Truncate(
+			ctx,
+			s.DB,
+			models.TableNameCoupon,
+			models.TableNameUserCoupon,
+			models.TableNameUser,
+		)
+
+		user := &models.User{Username: "coupon_receive", Phone: "13800000002"}
+		So(models.UserQuery.WithContext(ctx).Create(user), ShouldBeNil)
+
+		cp := &models.Coupon{
+			TenantID:       tenantID,
+			Title:          "Receive Test",
+			Type:           consts.CouponTypeFixAmount,
+			Value:          300,
+			MinOrderAmount: 0,
+			TotalQuantity:  1,
+		}
+		So(models.CouponQuery.WithContext(ctx).Create(cp), ShouldBeNil)
+
+		item, err := Coupon.Receive(ctx, tenantID, user.ID, cp.ID)
+		So(err, ShouldBeNil)
+		So(item, ShouldNotBeNil)
+		So(item.CouponID, ShouldEqual, cp.ID)
+
+		// second receive should return existing
+		item2, err := Coupon.Receive(ctx, tenantID, user.ID, cp.ID)
+		So(err, ShouldBeNil)
+		So(item2.CouponID, ShouldEqual, cp.ID)
+	})
+}
+
+func (s *CouponTestSuite) Test_ListAvailable() {
+	Convey("ListAvailable", s.T(), func() {
+		ctx := s.T().Context()
+		tenantID := int64(3)
+		database.Truncate(
+			ctx,
+			s.DB,
+			models.TableNameCoupon,
+			models.TableNameUserCoupon,
+			models.TableNameUser,
+		)
+
+		user := &models.User{Username: "coupon_available", Phone: "13800000003"}
+		So(models.UserQuery.WithContext(ctx).Create(user), ShouldBeNil)
+
+		cp := &models.Coupon{
+			TenantID:       tenantID,
+			Title:          "Available Test",
+			Type:           consts.CouponTypeFixAmount,
+			Value:          500,
+			MinOrderAmount: 1000,
+		}
+		So(models.CouponQuery.WithContext(ctx).Create(cp), ShouldBeNil)
+
+		uc := &models.UserCoupon{
+			UserID:   user.ID,
+			CouponID: cp.ID,
+			Status:   consts.UserCouponStatusUnused,
+		}
+		So(models.UserCouponQuery.WithContext(ctx).Create(uc), ShouldBeNil)
+
+		list, err := Coupon.ListAvailable(ctx, tenantID, user.ID, 500)
+		So(err, ShouldBeNil)
+		So(len(list), ShouldEqual, 0)
+
+		list, err = Coupon.ListAvailable(ctx, tenantID, user.ID, 1200)
+		So(err, ShouldBeNil)
+		So(len(list), ShouldEqual, 1)
+		So(list[0].CouponID, ShouldEqual, cp.ID)
+	})
+}