How to identify / verify FaceTime contact information?

Question

I am making an iOS application with FaceTime support. I am using FaceTime URL schemes to run FaceTime, which works great. I want users to be able to select contacts from their address book, store their FaceTime contact information and use it later.

A contact can contain several contact details (phone number, several email addresses, etc.). How can I determine which one needs FaceTime? I understand that in iOS 7, when a user selects FaceTime for a contact from his contact list, he will try to simultaneously call all his phone numbers / email address. Is there any way to do this from my application? Alternatively, is there a way for my application to check if the contact information is a valid FaceTime contact?

thank