facebook register/login
https://m.facebook.com/dialog/oauth?client_id=your-client-id&redirect_uri=xxx&scope=listof-information-you-want

https://graph.facebook.com/oauth/access_token?redirect_uri=xxx&client_id=xxx&client_secret=xxx&code=xxxx

https://graph.facebook.com/me?method=GET&metadata=true&format=json&access_token=access_token