Distinguish between localHangup, remoteHangup, and call failure.
This allows us to put CallKit in the proper state, ready to receive new
calls without having a backlog of phantom calls which haven't been
properly removed.
Note the "call error" occurs at the point ICE fails, which takes a
while. Anecdotally, like 10 seconds, which feels like a long to be
talking into the ether.
I briefly considered failing at 'disconnected', which happens much
sooner, but that's actually a recoverable state. E.g. if you toggle
airplane mode you can see that you bounce into `disconnected` and then
back to `connected`, so I don't think we'd want to fail the call as long
as WebRTC considers it "recoverable".
// FREEBIE
The removed code was from an older eon. CallService shouldn't be touched
except via the CallUIAdapter since only there is the omnipresent
distinction between CallKit vs. NonCallKit made.
i.e. when the RTCAudioSession get's started depends on the
CallUIAdaptee.
// FREEBIE
TODO: this is going to be weird when two parties are *just* enabling
webrtc for the first time. We might want to do something as drastic as
refetch contact information before completing the call.
// FREEBIE
coordinate SignalProtocol encryption/decryption on a single serial
queue. Previously message sending encrypted on the sending thread, while
message receiving decrypted on the main thread.
// FREEBIE
And run all non-cipher code on the main thread.
Note: Running encryption on the sessionCipher queue is more about
serializing access to session mutations than it is about any performance
gains.
// FREEBIE
...in response to CR, move the AudioService off of the CallViewController
Adopt multiple observer pattern vs. a singular delegate. Doing so
required implementing some machinery to address the ARC (see:
Weak.swift)
// FREEBIE
Implement speakerphone toggle directly. Previously we were using
AppAudioManager for several things, but this is that last lingering bit.
Much of the AppAudioManager code is based on RedPhone calling, so by
removing the dependency we pave the way to throw that code away.
// FREEBIE
8 Cases considered:
(Silent Switch toggled vs. Silent Switch not-toggled)
x (App in Foreground vs. App in Background)
x (CallKit vs. NonCallKit)
CallKit already does the "right thing"
// FREEBIE
