It looks like there is a good amount of config for handling different providers. Have you check out OAuth.io and its opensource core oauthd?:

https://github.com/oauth-io/oauthd

https://github.com/oauth-io/oauth-js

It's a simple node app and js sdk that lets you handle providers in a standardized way.

I created a ruby omniauth strategy that simplifies multiple provider support on the backend. A similar approach could be applied to any language:

https://github.com/jgrowl/omniauth-oauthio