Substance Painter Python API - access existing layers and groups?

I'm writing an automation tool that will process hundreds of .spp files and output textures from them based on our custom preset. For the most part everything is working.

The tricky part is that some of the assets have texture/color variations that are stored in grouped layers such as "0001" , "0002", "0003" etc.  Only one of those groups is visible at a time, the rest are hidden. 

I see no info about layers in the documentaion, is it possible to get access to document's layers, layer types, and their names? Is it possible to toggle their visibility?   Ideally I want the tool to be able to toggle folders on and off and export each variation