Joomla API authentification, Kunena and AUP integration

Hello, I want to create a gaming community that will use Joomla 3, Kunena, and Alphauserpoints components. As template I’ll use Purity III. What I need from you is to create a CMP that will use the Steam API to register users. Only this option should be available for registration, users should not be able to register on the site using shortcuts to Joomla default registration or Kunena/AUP registration pages. The auth process should be like this: user clicks on login with steam button redirected to steam site to login with his user and pass returning to my site he will be asked for an email address if he provides a valid email address he will be registered else NOT if registered a small icon with his avatar and profile name from steam and a logout link will appear instead of “login with steam button” On auth we need to pull all info available on user, steamID64, Profile Name, Avatar, Country etc. and that info should be on his Kunena and AUP Profile. The id64 will be the login name in joomla because that is the unique identifier on steam, the Profile Name will be Name in Joomla, that we will use it to display on Kunena, and if it changed on steam it should also get automatically changed on site on next login.