GER-1260 - make authenticator private and expose methods for passthrough and initial capture

[germ-mark]

This hides the implementation of ATProtoAuthenticator wrapping an Authenticator object

[ThisIsMissEm]

This is all temporary until the authenticate() method returns the session, right?

[germ-mark]

Yes. And it’s my assertion/belief that once authenticate returns we should have no further need for the authenticator and the (local) login storage. The resulting token gets passed to another object which spawns its own authenticator object(s)

[germ-mark]

Alternatively, we could define a login storage that handles both initial and ongoing storage, that gets handed off from in-memory storage to persistent storage. That seems more complex, but could handle refresh calls that happen after authenticate() returns

[ThisIsMissEm]

Yes, refresh could be required immediately after authenticate() in some certain scenarios.

ChimeHQ/OAuthenticator#46 — here's the change to return the current session from the authenticate method.

[ThisIsMissEm]

That seems more complex, but could handle refresh calls that happen after authenticate() returns

It is slightly more complex, but guarantees safe handling everywhere, and prevents leaking the Login, so maybe with that we wouldn't need #46 above.

[ThisIsMissEm]

This will work, but it looks a little weird

The sendAuthenticatedRequest in ATProtoLiteClient will trigger calls to loginStorage to store changes to the tokens, or even clear the current login. So it'd probably make sense to have a single shared LoginStorage implementation that stores the data correctly and securely, then share that across all authenticators.

In this case, until we have authenticate() returning the Login we'd need to use a custom loginStorage here, but it should probably still interact with the global implementation, I think.

[germ-mark]

To properly hide the implementation in tests, ended up defining an ATProtoInterface, behind which are a struct that encapsulates the online calls, and an actor that mocks out ATProtocol for multiple test apps to interact with

[germ-mark]

rebased atop PR #1 and added a similar interface for load Protected Metadata so we can run offline tests