feat: sorting for primitive fields

# Conflicts:
#	frontend/src/App.vue

internal/utils/sorting.go

@@ -0,0 +1,40 @@
+package utils
+
+import (
+	"app/internal/database"
+	"errors"
+	"fmt"
+	"reflect"
+)
+
+// SortByOrder Order items by specified field and a sort type
+// Example: SortByOrder(map[string]string{"name": "ASC"}, &models.Post{})
+// ASC - по возрастанию (от А до Я)
+// DESC - по убыванию (от Я до А)
+func SortByOrder[T any](fieldsSortOrder map[string]string, entity T) ([]*T, error) {
+	var (
+		orderQuery string
+		items      []*T
+	)
+
+	for name, order := range fieldsSortOrder {
+		structInfo := reflect.ValueOf(entity).Type()
+		_, fieldExist := structInfo.FieldByName(name)
+
+		if !fieldExist {
+			return nil, errors.New(fmt.Sprintf("Field `%s` not found", name))
+		}
+
+		if order != "ASC" && order != "DESC" {
+			return nil, errors.New(fmt.Sprintf("Field `%s` can only be sorted by ASC or DESC", name))
+		}
+
+		orderQuery += fmt.Sprintf("%s %s", name, order)
+	}
+
+	result := database.GetInstance().Order(orderQuery).Find(&items)
+	if result.Error != nil {
+		return items, result.Error
+	}
+	return items, nil
+}