Define a clear way to switch between different authentication methods

[UServiceRepo]

User may be authenticated via id/pass, tokens, and 3rd party authentication services.
Define a clear way to switch between different options.
Current idea is to define a class that will represent each method, and create an array with defined enum to select each method as needed.

Also, multiple authentication methods may be used simultaneously. It is also possible that only a select few methods are available, depending on the configuration.