Change role after the user has read all the posts in a category

Hi to all community.
So i’m creating a platform with “X” categories and “X” roles with the same name to each category.

I would like to know how to change the user’s role after they have read all the posts in a category. When the role changes, the user will have access to the next category. And so on…

To make the categories private and to create the related groups of users I’m using the Role Scoper plugin.

Does anyone know a plugin to do this? I searched but without any success…

Thanks to all!