Users can rate product after their order status changed to completed I want to give permission to user to rate a product when their order status set to completed. For that I've tried using rules but in action i was not able to set permission for particular user whose order completed.

I'm using five star drupal module which is using voting api. Need help to implement this feature.
What I am suggesting is to create a new node type "review" and referenced this to product with references module. Create one view to display reviews or rating on product page. Create one permission or need to hook for permission to access already purchase of same product.