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