change add-product endpoint + remove-product

app/repos/cartsRepo/cartsRepo.go

@@ -1,9 +1,13 @@
 package cartsRepo
 
 import (
+	"errors"
+
 	"git.ma-al.com/goc_daniel/b2b/app/db"
 	"git.ma-al.com/goc_daniel/b2b/app/model"
 	constdata "git.ma-al.com/goc_daniel/b2b/app/utils/const_data"
+	"git.ma-al.com/goc_daniel/b2b/app/utils/responseErrors"
+	"gorm.io/gorm"
 )
 
 type UICartsRepo interface {
@@ -15,7 +19,8 @@ type UICartsRepo interface {
 	RetrieveCartsInfo(user_id uint) ([]model.CustomerCart, error)
 	RetrieveCart(user_id uint, cart_id uint) (*model.CustomerCart, error)
 	CheckProductExists(product_id uint, product_attribute_id *uint) (bool, error)
-	AddProduct(user_id uint, cart_id uint, product_id uint, product_attribute_id *uint, amount uint) error
+	AddProduct(cart_id uint, product_id uint, product_attribute_id *uint, amount uint, set_amount bool) error
+	RemoveProduct(cart_id uint, product_id uint, product_attribute_id *uint) error
 }
 
 type CartsRepo struct{}
@@ -129,14 +134,61 @@ func (repo *CartsRepo) CheckProductExists(product_id uint, product_attribute_id
 	}
 }
 
-func (repo *CartsRepo) AddProduct(user_id uint, cart_id uint, product_id uint, product_attribute_id *uint, amount uint) error {
-	product := model.CartProduct{
-		CartID:             cart_id,
-		ProductID:          product_id,
-		ProductAttributeID: product_attribute_id,
-		Amount:             amount,
-	}
-	err := db.DB.Create(&product).Error
+func (repo *CartsRepo) AddProduct(cart_id uint, product_id uint, product_attribute_id *uint, amount uint, set_amount bool) error {
+	var product model.CartProduct
 
-	return err
+	err := db.DB.
+		Where(&model.CartProduct{
+			CartID:             cart_id,
+			ProductID:          product_id,
+			ProductAttributeID: product_attribute_id,
+		}).
+		First(&product).Error
+
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			if amount < 1 {
+				return responseErrors.ErrAmountMustBePositive
+			} else if amount > constdata.MAX_AMOUNT_OF_PRODUCT_IN_CART {
+				return responseErrors.ErrAmountMustBeReasonable
+			}
+
+			product = model.CartProduct{
+				CartID:             cart_id,
+				ProductID:          product_id,
+				ProductAttributeID: product_attribute_id,
+				Amount:             amount,
+			}
+
+			return db.DB.Create(&product).Error
+		}
+
+		// Some other DB error
+		return err
+	}
+
+	// Product already exists in cart
+	if set_amount {
+		product.Amount = amount
+	} else {
+		product.Amount = product.Amount + amount
+	}
+
+	if product.Amount < 1 {
+		return responseErrors.ErrAmountMustBePositive
+	} else if product.Amount > constdata.MAX_AMOUNT_OF_PRODUCT_IN_CART {
+		return responseErrors.ErrAmountMustBeReasonable
+	}
+
+	return db.DB.Save(&product).Error
+}
+
+func (repo *CartsRepo) RemoveProduct(cart_id uint, product_id uint, product_attribute_id *uint) error {
+	return db.DB.
+		Where(&model.CartProduct{
+			CartID:             cart_id,
+			ProductID:          product_id,
+			ProductAttributeID: product_attribute_id,
+		}).
+		Delete(&model.CartProduct{}).Error
 }