libpurple: get list of ALL buddies of a user

We have an application where we want to let our users retrieve their full buddy list ( online + offline) from the different networks (yahoo, gmail, hotmail, etc).

The user will enter their user/pass for each network and our app will connect the users to those networks with libpurple.

Two questions: 

1. is is possible to retrieve the full list of this user's buddies ? if so, what function should I use ?

2. is it possible to not bring the user online but still be able to get the full buddy list ?

We want to use only libpurple for the above and not any custom scripts for each network...

Thank you,

Cristian