SSO using a custom oAuth

Good afternoon.

Currently our application works as an OAuth provider, this is the behaviour we expect related to chat integration into our platform:

1. The user sign-in in our platform by first time using his credentials.

2. The user then log-in in chat using our OAuth service, chat system should automatically procede to create a new user inside chat DB without requesting credentials or any form fill, instead it should use the data provided by our custom OAuth procedure.

3. Any time this user sign-in in our platform in the future, the chat app should automatically sign-in as well.

My question is: does Mattermost has a single sign-on (SSO) method based on custom oAuth that allow us to perform a procedure as described above?.

If not, are you planning to implement that?, if true, will you make this available only for the comercial version?

Thank you.