Reading and updating Gradle files and Android files from the Android Studio / IntelliJ plugin

Question

Im working on an Android Studio plugin that integrates the SDK app into Android. Similar to Fabric.io do.

I was able to follow the documentation to create a simple plugin. Now I am trying to read the Gradle assembly file and the activity file and the code for adding dependencies to the project, how can I do this?

Note. Any pointers or sample projects will be helpful, I tried to look at sample projects, but the only interesting thing I found was some plugins that use this package com.android.tools.idea.gradlebut are not sure where these APIs are publicly documented.

Edit:

I found more information, the package I mentioned above is an IDE Android Plugin. I could also use some of its methods if I added jar to my project. I still have problems running the code, it will be updated if I find out why it breaks.