Batch Folder Rename through JavaScript

Please guide me how to batch rename folders through a JavaScript according to my following requirement:

1. The folders to be renamed using the full first and last name initial separated by a comma.

2. Every folder name must be in small letters

For Example:

Lets suppose the folder's actual name is John Doe / John Steven Doe and etc. So I want the folders to be renamed as john.d / john.d