Filter products per machine

products/app/api/router.go

@@ -24,7 +24,22 @@ func handlePing(c *gin.Context) {
 
 func handleGetProducts(dbConn *gorm.DB) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		products := db.GetProducts(dbConn)
+		var (
+			machineId *int = nil
+			err       error
+			mId       int
+		)
+
+		machineIdStr, ok := c.GetQuery("machineId")
+		if ok && len(machineIdStr) > 0 {
+			if mId, err = strconv.Atoi(machineIdStr); err != nil {
+				raiseBadRequestError(c, "Invalid machineId filter")
+				return
+			}
+			machineId = &mId
+		}
+
+		products := db.GetProducts(dbConn, machineId)
 
 		c.JSON(
 			http.StatusOK,

products/app/db/repository.go

@@ -2,10 +2,19 @@ package db
 
 import "gorm.io/gorm"
 
-func GetProducts(dbConn *gorm.DB) *[]Product {
+func GetProducts(dbConn *gorm.DB, machineId *int) *[]Product {
-	var products []Product
+	var (
+		products []Product
+		query    = dbConn
+	)
 
-	dbConn.Order("name").Find(&products)
+	if machineId != nil {
+		query = query.
+			Joins("LEFT JOIN machine_products mp ON mp.product_id = products.id").
+			Where("mp.machine_id = ?", machineId)
+	}
+
+	query.Order("name").Find(&products)
 
 	return &products
 }