fix: update associations

internal/services/update_associations.go

@@ -0,0 +1,41 @@
+package services
+
+import (
+	"errors"
+	"reflect"
+
+	"gorm.io/gorm"
+)
+
+func UpdateAssociations(db *gorm.DB, item interface{}) error {
+    // We expect a pointer to a struct so we can do db.Model(item).
+    val := reflect.ValueOf(item)
+    if val.Kind() != reflect.Ptr {
+        return errors.New("item must be a pointer to a struct")
+    }
+
+    elem := val.Elem()
+    if elem.Kind() != reflect.Struct {
+        return errors.New("item must be a pointer to a struct")
+    }
+
+    t := elem.Type()
+    for i := 0; i < elem.NumField(); i++ {
+        fieldVal := elem.Field(i)
+        fieldType := t.Field(i)
+
+        // Only process exported fields (capitalized) and slices.
+        if fieldType.PkgPath == "" && fieldVal.Kind() == reflect.Slice {
+            // For clarity, the association name is the struct field name by default.
+            assocName := fieldType.Name
+
+            // Replace the association with the current slice value.
+            // If you only want to replace on non-nil or non-empty slices, you can add extra checks here.
+            if err := db.Model(item).Association(assocName).Replace(fieldVal.Interface()); err != nil {
+                return err
+            }
+        }
+    }
+
+    return nil
+}