Move state from CallViewController -> Call

I think whenever reasonable we prefer to consodlidate state on the call

// FREEBIE

Signal/src/ViewControllers/CallViewController.swift

@@ -119,26 +119,6 @@ class CallViewController: UIViewController, CallObserver, CallServiceObserver, R
         }
     }
 
-    var audioSource: AudioSource? {
-        didSet {
-            if audioSource != oldValue {
-                if let audioSource = audioSource {
-                    if audioSource.isBuiltInSpeaker {
-                        // TODO seems like CVC knows too much about AudioSource.
-                        // Maybe these conditionals belong in the callUIAdapter? Or audioService?
-                        //                    self.callUIAdapter.audioService.setPreferredInput(audioSource: audioSource)
-
-                        self.callUIAdapter.setIsSpeakerphoneEnabled(call: self.call, isEnabled: true)
-                        return
-                    }
-                }
-
-                self.callUIAdapter.setIsSpeakerphoneEnabled(call: self.call, isEnabled: false)
-                self.callUIAdapter.audioService.setPreferredInput(call: self.call, audioSource: audioSource)
-            }
-        }
-    }
-
     // MARK: Initializers
 
     required init?(coder aDecoder: NSCoder) {
@@ -390,11 +370,8 @@ class CallViewController: UIViewController, CallObserver, CallServiceObserver, R
 
         let currentAudioSource = callUIAdapter.audioService.currentAudioSource(call: self.call)
         for audioSource in self.appropriateAudioSources {
-            // TODO add image
             let routeAudioAction = UIAlertAction(title: audioSource.localizedName, style: .default) { _ in
-                // Disable any speakerphone
-                // TODO will this update the UI appropriately?
-                self.audioSource = audioSource
+                self.callUIAdapter.setAudioSource(call: self.call, audioSource: audioSource)
             }
 
             // HACK: private API to create checkmark for active audio source.
@@ -879,7 +856,12 @@ class CallViewController: UIViewController, CallObserver, CallServiceObserver, R
         Logger.info("\(TAG) called \(#function)")
         button.isSelected = !button.isSelected
         if let call = self.call {
-            callUIAdapter.setIsSpeakerphoneEnabled(call: call, isEnabled: button.isSelected)
+            if button.isSelected {
+                callUIAdapter.setAudioSource(call: call, audioSource: AudioSource.builtInSpeaker)
+            } else {
+                // use default audio source
+                callUIAdapter.setAudioSource(call: call, audioSource: nil)
+            }
         } else {
             Logger.warn("\(TAG) pressed mute, but call was unexpectedly nil")
         }
@@ -993,7 +975,7 @@ class CallViewController: UIViewController, CallObserver, CallServiceObserver, R
         self.updateCallUI(callState: call.state)
     }
 
-    internal func speakerphoneDidChange(call: SignalCall, isEnabled: Bool) {
+    internal func audioSourceDidChange(call: SignalCall, audioSource: AudioSource?) {
         AssertIsOnMainThread()
         self.updateCallUI(callState: call.state)
     }

Signal/src/call/CallAudioService.swift

@@ -139,10 +139,19 @@ struct AudioSource: Hashable {
         Logger.verbose("\(TAG) in \(#function) is no-op")
     }
 
-    internal func speakerphoneDidChange(call: SignalCall, isEnabled: Bool) {
+    internal func audioSourceDidChange(call: SignalCall, audioSource: AudioSource?) {
         AssertIsOnMainThread()
 
         ensureProperAudioSession(call: call)
+
+        // It's importent to set preferred input *after* ensuring properAudioSession
+        // because some sources are only valid for certain categories.
+        let session = AVAudioSession.sharedInstance()
+        do {
+            try session.setPreferredInput(audioSource?.portDescription)
+        } catch {
+            owsFail("\(TAG) setPreferredInput in \(#function) failed with error: \(error)")
+        }
     }
 
     internal func hasLocalVideoDidChange(call: SignalCall, hasLocalVideo: Bool) {

Signal/src/call/CallService.swift

@@ -1442,7 +1442,7 @@ protocol CallServiceObserver: class {
         // Do nothing
     }
 
-    internal func speakerphoneDidChange(call: SignalCall, isEnabled: Bool) {
+    internal func audioSourceDidChange(call: SignalCall, audioSource: AudioSource?) {
         AssertIsOnMainThread()
         // Do nothing
     }

Signal/src/call/SignalCall.swift

@@ -26,7 +26,7 @@ protocol CallObserver: class {
     func stateDidChange(call: SignalCall, state: CallState)
     func hasLocalVideoDidChange(call: SignalCall, hasLocalVideo: Bool)
     func muteDidChange(call: SignalCall, isMuted: Bool)
-    func speakerphoneDidChange(call: SignalCall, isEnabled: Bool)
+    func audioSourceDidChange(call: SignalCall, audioSource: AudioSource?)
 }
 
 /**
@@ -104,18 +104,25 @@ protocol CallObserver: class {
         }
     }
 
-    var isSpeakerphoneEnabled = false {
+    var audioSource: AudioSource? = nil {
         didSet {
             AssertIsOnMainThread()
-
-            Logger.debug("\(TAG) isSpeakerphoneEnabled changed: \(oldValue) -> \(self.isSpeakerphoneEnabled)")
+            Logger.debug("\(TAG) audioSource changed: \(String(describing:oldValue)) -> \(String(describing: audioSource))")
 
             for observer in observers {
-                observer.value?.speakerphoneDidChange(call: self, isEnabled: isSpeakerphoneEnabled)
+                observer.value?.audioSourceDidChange(call: self, audioSource: audioSource)
             }
         }
     }
 
+    var isSpeakerphoneEnabled: Bool {
+        guard let audioSource = self.audioSource else {
+            return false
+        }
+
+        return audioSource.isBuiltInSpeaker
+    }
+
     var isOnHold = false
 
     var connectedDate: NSDate?

Signal/src/call/UserInterface/CallUIAdapter.swift

@@ -207,13 +207,13 @@ extension CallUIAdaptee {
         adaptee.setHasLocalVideo(call: call, hasLocalVideo: hasLocalVideo)
     }
 
-    internal func setIsSpeakerphoneEnabled(call: SignalCall, isEnabled: Bool) {
+    internal func setAudioSource(call: SignalCall, audioSource: AudioSource?) {
         AssertIsOnMainThread()
 
-        // Speakerphone is not handled by CallKit (e.g. there is no CXAction), so we handle it w/o going through the
-        // adaptee, relying on the AudioService CallObserver to put the system in a state consistent with the call's 
+        // AudioSource is not handled by CallKit (e.g. there is no CXAction), so we handle it w/o going through the
+        // adaptee, relying on the AudioService CallObserver to put the system in a state consistent with the call's
         // assigned property.
-        call.isSpeakerphoneEnabled = isEnabled
+        call.audioSource = audioSource
     }
 
     // CallKit handles ringing state on it's own. But for non-call kit we trigger ringing start/stop manually.