I am building a social platform in Codeigniter..And i wish to implement a Social Login Option like StackOverflow(which uses OpenId) where user can select Facebook, LinkedIn, Twitter or Google to login into my site.. I know of few PHP libraries like OpenId, A3M for CI..
My query is will A3M detect a user loggin in via Linked In is already a signed-up user who initially used FB and map both the Ids with the same user instead of generating new User.
Is there a better suggested alternative to A3M for my requiremnets