feat: sorting for primitive fields

# Conflicts:
#	frontend/src/App.vue

internal/utils/replace_empty_to_nil.go

@@ -0,0 +1,49 @@
+package utils
+
+import "reflect"
+
+// ReplaceEmptySlicesWithNil takes a pointer to any struct (or struct-like type)
+// and replaces all empty slices with nil, traversing nested fields recursively.
+func ReplaceEmptySlicesWithNil(v interface{}) {
+	// Must be a pointer so we can set fields
+	rv := reflect.ValueOf(v)
+	if rv.Kind() != reflect.Ptr {
+		panic("ReplaceEmptySlicesWithNil expects a pointer to a struct")
+	}
+
+	replaceEmptySlices(rv.Elem())
+}
+
+// replaceEmptySlices is the recursive helper that does the actual reflection work.
+func replaceEmptySlices(v reflect.Value) {
+	switch v.Kind() {
+	case reflect.Ptr:
+		// If it is a pointer, recurse on the element it points to.
+		if !v.IsNil() {
+			replaceEmptySlices(v.Elem())
+		}
+
+	case reflect.Struct:
+		// For a struct, iterate each field and process it.
+		for i := 0; i < v.NumField(); i++ {
+			fieldVal := v.Field(i)
+			if !fieldVal.CanSet() {
+				// If we can't set the field (e.g. unexported), skip it
+				continue
+			}
+			replaceEmptySlices(fieldVal)
+		}
+
+	case reflect.Slice:
+		// If it is a slice, check if it's empty; if it is, set it to nil.
+		if v.Len() == 0 && v.CanSet() {
+			// v.Set(reflect.Zero(v.Type())) sets slice to nil
+			v.Set(reflect.Zero(v.Type()))
+		} else {
+			// If not empty, we should recurse on each element in case it's a struct.
+			for i := 0; i < v.Len(); i++ {
+				replaceEmptySlices(v.Index(i))
+			}
+		}
+	}
+}