add CreateProduct method to ProductRepository for product creation

Author: GabrielNat1

cmd/main.go

@@ -31,6 +31,7 @@ func main() {
 	})
 
 	server.GET("/products", ProductController.GetProducts)
+	server.POST("/product", ProductController.CreateProduct)
 
 	server.Run(":8000")
 

controller/product_controller.go

@@ -1,6 +1,7 @@
 package controller
 
 import (
+	"api-go/model"
 	"api-go/usecase"
 	"net/http"
 
@@ -26,3 +27,21 @@ func (p *productController) GetProducts(ctx *gin.Context) {
 
 	ctx.JSON(http.StatusOK, products)
 }
+
+func (p *productController) CreateProduct(ctx *gin.Context) {
+
+	var product model.Product
+	err := ctx.BindJSON(&product)
+	if err != nil {
+		ctx.JSON(http.StatusBadRequest, err)
+		return
+	}
+
+	insertedProduct, err := p.productUseCase.CreateProduct(product)
+	if err != nil {
+		ctx.JSON(http.StatusInternalServerError, err)
+		return
+	}
+
+	ctx.JSON(http.StatusCreated, insertedProduct)
+}

repository/product_repository.go

@@ -45,3 +45,24 @@ func (pr *ProductRepository) GetProducts() ([]model.Product, error) {
 
 	return productList, nil
 }
+
+func (pr *ProductRepository) CreateProduct(product model.Product) (int, error) {
+
+	var id int
+	query, err := pr.connection.Prepare("INSERT INTO product" +
+		"(product_name, price)" +
+		"VALUES($1, $2) RETURNING id")
+	if err != nil {
+		fmt.Println(err)
+		return 0, err
+	}
+
+	err = query.QueryRow(product.Name, product.Price).Scan(&id)
+	if err != nil {
+		fmt.Println(err)
+		return 0, err
+	}
+
+	query.Close()
+	return id, nil
+}

usecase/product_usecase.go

@@ -18,3 +18,15 @@ func NewProductUseCase(repo repository.ProductRepository) *ProductUseCase {
 func (pu *ProductUseCase) GetProducts() ([]model.Product, error) {
 	return pu.repository.GetProducts()
 }
+
+func (pu *ProductUseCase) CreateProduct(product model.Product) (model.Product, error) {
+
+	productId, err := pu.repository.CreateProduct(product)
+	if err != nil {
+		return model.Product{}, err
+	}
+
+	product.ID = productId
+
+	return product, nil
+}