Implement missing feature

src/helpers/virtual_directory_helper.rs

@@ -4,6 +4,7 @@
 
 use crate::data::error::ResultBoxError;
 use crate::data::group_id::GroupID;
+use crate::data::user::UserID;
 use crate::helpers::{account_helper, groups_helper};
 use crate::utils::virtual_directories_utils::check_virtual_directory;
 
@@ -20,8 +21,10 @@ pub fn check_availability(dir: &str, target_id: u64, target_type: VirtualDirType
 
     match target_type {
         VirtualDirType::USER => {
-            // TODO : implement this check
-            unimplemented!();
+            Ok(
+                account_helper::check_user_directory_availability(dir, Some(UserID::new(target_id)))? &&
+                    groups_helper::check_directory_availability(dir, None)?
+            )
         }
         VirtualDirType::GROUP => {
             Ok(