fix(healthchat): rewire the NSE and call service to upstream's settings

ElementX/Sources/Services/ElementCall/ElementCallService.swift

@@ -9,6 +9,7 @@
 import AVFoundation
 import CallKit
 import Combine
+import ElementCall
 import Foundation
 import MatrixRustSDK
 import PushKit
@@ -26,13 +27,14 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
         let roomID: String
         let rtcNotificationID: String?
         let isVoiceCall: Bool
+        var isNative = false
     }
     
+    private let appSettings: AppSettings
     private let pushRegistry: PKPushRegistry
-    private let callController = CXCallController()
+    private let callController: CXCallControllerProtocol
     private let callProvider: CXProviderProtocol
     private let timeProvider: TimeProvider
-    private let appSettings: AppSettings
     
     private weak var clientProxy: ClientProxyProtocol? {
         didSet {
@@ -52,6 +54,10 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
     
     private var endUnansweredCallTask: Task<Void, Never>?
     
+    /// A call answered for the native stack, until the stack takes it over.
+    private var answeredNativeCallID: CallID?
+    private var endPendingCallTask: Task<Void, Never>?
+    
     private var ongoingCallID: CallID? {
         didSet { ongoingCallRoomIDSubject.send(ongoingCallID?.roomID) }
     }
@@ -68,11 +74,26 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
     
     private var declineListenerHandle: TaskHandle?
     
-    init(callProvider: CXProviderProtocol? = nil, timeProvider: TimeProvider? = nil, appSettings: AppSettings) {
+    /// The native call stack, for as long as there's a session running calls through it.
+    private var nativeCallStack: NativeCallStack?
+    private var nativeCallCancellable: AnyCancellable?
+    private var mediaProvider: MediaProviderProtocol?
+    
+    var nativeCallController: ElementCallController? {
+        nativeCallStack?.controller
+    }
+    
+    private var cancellables = Set<AnyCancellable>()
+    
+    init(appSettings: AppSettings,
+         callProvider: CXProviderProtocol? = nil,
+         callController: CXCallControllerProtocol? = nil,
+         timeProvider: TimeProvider? = nil) {
+        self.appSettings = appSettings
+        self.callController = callController ?? CXCallController()
         pushRegistry = PKPushRegistry(queue: nil)
         
         self.timeProvider = timeProvider ?? TimeProvider(clock: ContinuousClock(), now: Date.init)
-        self.appSettings = appSettings
         
         if let callProvider {
             self.callProvider = callProvider
@@ -97,45 +118,145 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
         pushRegistry.desiredPushTypes = [.voIP]
         
         self.callProvider.setDelegate(self, queue: nil)
+        
+        appSettings.nativeCallEnabledPublisher
+            .sink { [weak self] _ in
+                self?.updateNativeCallStack()
+            }
+            .store(in: &cancellables)
     }
     
-    func setClientProxy(_ clientProxy: any ClientProxyProtocol) {
-        self.clientProxy = clientProxy
+    func setUserSession(_ userSession: UserSessionProtocol?) {
+        // A stack is built against one client proxy and can't be handed to another, which is what a
+        // soft logout or a cache clear brings: a new session without the sign out that drops this one.
+        if userSession?.clientProxy !== clientProxy {
+            stopNativeCallStack()
         }
         
-    func setupCallSession(roomID: String, roomDisplayName: String) async {
+        clientProxy = userSession?.clientProxy
+        mediaProvider = userSession?.mediaProvider
+        
+        updateNativeCallStack()
+    }
+    
+    @discardableResult
+    func handleNativeCallRequest(roomProxy: JoinedRoomProxyProtocol, isVoiceCall: Bool) -> Bool {
+        guard let nativeCallStack else {
+            return false
+        }
+        
+        nativeCallStack.handleCallRequest(roomProxy: roomProxy, isVoiceCall: isVoiceCall)
+        return true
+    }
+    
+    func minimizeNativeCall() {
+        nativeCallStack?.minimize()
+    }
+    
+    func restoreNativeCall() {
+        nativeCallStack?.restore()
+    }
+    
+    func setupCallSession(roomID: String, roomDisplayName: String, isVideo: Bool) async {
+        // Unlike the push handling below, this always runs with a session, so the stack itself is
+        // the answer rather than the setting that would have built one.
+        let isNative = nativeCallStack != nil
+        MXLog.info("Setting up a call session, native: \(isNative), video: \(isVideo), replacing an ongoing call: \(ongoingCallID != nil)")
+        
         // Drop any ongoing calls when starting a new one
         if ongoingCallID != nil {
-            tearDownCallSession()
+            tearDownCallSession(sendEndCallAction: true)
         }
         
         // If this starting from a ring reuse those identifiers
         // Make sure the roomID matches
-        let callID = if let incomingCallID, incomingCallID.roomID == roomID {
+        var callID = if let incomingCallID, incomingCallID.roomID == roomID {
             incomingCallID
         } else {
-            CallID(callKitID: UUID(), roomID: roomID, rtcNotificationID: nil, isVoiceCall: false)
+            CallID(callKitID: UUID(), roomID: roomID, rtcNotificationID: nil, isVoiceCall: !isVideo)
         }
+        callID.isNative = isNative
+        let isAnsweringIncomingCall = callID.rtcNotificationID != nil
         
         clearIncomingCallState()
         ongoingCallID = callID
         
-        // Don't bother starting another CallKit session as it won't work properly
+        // A web view call must not be tracked by CallKit, as that gives this process exclusive
+        // access to media and the web view runs in another (see `CXAnswerCallAction`).
         // https://developer.apple.com/forums//thread/767949?answerId=812951022#812951022
-        
-        // let handle = CXHandle(type: .generic, value: roomDisplayName)
-        // let startCallAction = CXStartCallAction(call: callID.callKitID, handle: handle)
-        // startCallAction.isVideo = true
-        
-        // do {
-        //     try await callController.request(CXTransaction(action: startCallAction))
-        // } catch {
-        //     MXLog.error("Failed requesting start call action with error: \(error)")
-        // }
+        guard isNative else {
+            return
         }
         
-    func tearDownCallSession() {
+        // Answering the ringing call: it is already reported, keep it.
+        guard !isAnsweringIncomingCall else {
+            return
+        }
+        
+        let handle = CXHandle(type: .generic, value: roomID)
+        let startCallAction = CXStartCallAction(call: callID.callKitID, handle: handle)
+        startCallAction.contactIdentifier = roomDisplayName
+        startCallAction.isVideo = isVideo
+        
+        // Awaited because our membership goes out straight after: a peer that sees it before the
+        // system knows about the call reads the call as answered elsewhere.
+        await requestTransaction(CXTransaction(action: startCallAction), describedAs: "start call")
+        
+        // Without this the system call UI shows the handle, i.e. the room ID.
+        let update = CXCallUpdate()
+        update.localizedCallerName = roomDisplayName
+        update.remoteHandle = handle
+        update.hasVideo = isVideo
+        callProvider.reportCall(with: callID.callKitID, updated: update)
+    }
+    
+    func reportCallSessionConnected(roomID: String) {
+        guard let ongoingCallID, ongoingCallID.roomID == roomID else {
+            // The system ends an outgoing call that never reports connecting, so a silent guard
+            // here shows up much later as a call that hangs itself up.
+            MXLog.warning("Not reporting the call as connected, no matching ongoing call")
+            return
+        }
+        
+        guard ongoingCallID.isNative else {
+            MXLog.info("Not reporting a web view call as connected, CallKit doesn't track it")
+            return
+        }
+        
+        MXLog.info("Reporting the call as connected")
+        callProvider.reportOutgoingCall(with: ongoingCallID.callKitID, connectedAt: nil)
+    }
+    
+    func tearDownCallSession(roomID: String) {
+        if ongoingCallID?.roomID == roomID {
             tearDownCallSession(sendEndCallAction: true)
+            return
+        }
+        
+        // Answered and handed over, but the stack couldn't take it. Ending it here rather than
+        // waiting for the watchdog takes the system call UI away straight away.
+        if answeredNativeCallID?.roomID == roomID {
+            MXLog.warning("Ending an answered call the native call stack didn't take over")
+            endPendingCall()
+            return
+        }
+        
+        MXLog.info("Not tearing down the call session, no call for room \(roomID)")
+    }
+    
+    func reportCallSessionEnded(roomID: String, reason: CXCallEndedReason) {
+        guard let ongoingCallID, ongoingCallID.roomID == roomID else {
+            MXLog.info("Not reporting the end of a call for \(roomID), it isn't the ongoing call")
+            return
+        }
+        
+        // A web view call is not tracked by CallKit, as in `reportCallSessionConnected`.
+        if ongoingCallID.isNative {
+            MXLog.info("Reporting the call as ended without us: \(reason.rawValue)")
+            callProvider.reportCall(with: ongoingCallID.callKitID, endedAt: nil, reason: reason)
+        }
+        
+        self.ongoingCallID = nil
     }
     
     func setAudioEnabled(_ enabled: Bool, roomID: String) {
@@ -157,6 +278,57 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
         }
     }
     
+    // MARK: - Native calls
+    
+    /// Builds or releases the call stack to match the session and the setting.
+    private func updateNativeCallStack() {
+        guard appSettings.nativeCallEnabled, let clientProxy else {
+            stopNativeCallStack()
+            return
+        }
+        
+        guard nativeCallStack == nil else { return }
+        
+        guard let transport = clientProxy.makeNativeCallTransport() else {
+            MXLog.error("Cannot start the native call stack without a transport")
+            return
+        }
+        
+        let style = ElementCallStyle(theme: NativeCallTheme(),
+                                     icons: NativeCallIcons(),
+                                     avatars: NativeCallAvatars(mediaProvider: mediaProvider),
+                                     strings: .init(you: L10n.commonYou,
+                                                    error: L10n.commonError,
+                                                    stop: L10n.actionStop,
+                                                    back: L10n.actionBack))
+        
+        // The stats overlay is raw RTP counters, so it follows whatever already reveals developer
+        // surface. Screen sharing stays off until the broadcast extension that makes it work lands.
+        let options = ElementCallOptions(isDeveloperModeEnabled: appSettings.developerOptionsEnabled)
+        
+        let stack = NativeCallStack(transport: transport,
+                                    system: NativeCallSystem(service: self),
+                                    options: options,
+                                    style: style)
+        nativeCallStack = stack
+        
+        nativeCallCancellable = stack.actions
+            .sink { [weak self] presentation in
+                self?.actionsSubject.send(.nativeCall(presentation))
+            }
+        
+        Task { await stack.start() }
+    }
+    
+    private func stopNativeCallStack() {
+        guard let nativeCallStack else { return }
+        self.nativeCallStack = nil
+        nativeCallCancellable = nil
+        
+        nativeCallStack.stop()
+        actionsSubject.send(.nativeCall(.dismiss))
+    }
+    
     // MARK: - PKPushRegistryDelegate
     
     func pushRegistry(_ registry: PKPushRegistry, didUpdate pushCredentials: PKPushCredentials, for type: PKPushType) {
@@ -226,7 +398,7 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
         // If not for audio call the app will not be put to foreground and the webview won't be able to handle the call...
         // Consequence: The call will be presented to the user as a video call in CallKit UI,
         // but once Element Call is launched it will correctly route to a voice-only call.
-        update.hasVideo = true
+        update.hasVideo = appSettings.nativeCallEnabled ? !isVoiceCall : true
         update.localizedCallerName = roomDisplayName
         // https://stackoverflow.com/a/41230020/730924
         update.remoteHandle = .init(type: .generic, value: roomID)
@@ -264,10 +436,19 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
     
     func provider(_ provider: CXProvider, didActivate audioSession: AVAudioSession) {
         MXLog.info("Call provider did activate audio session")
+        actionsSubject.send(.audioSessionActivated)
     }
     
     func provider(_ provider: CXProvider, didDeactivate audioSession: AVAudioSession) {
         MXLog.info("Call provider did deactivate audio session")
+        actionsSubject.send(.audioSessionDeactivated)
+    }
+    
+    func provider(_ provider: CXProvider, perform action: CXStartCallAction) {
+        // The native controller configured the audio session already; CallKit activates it and
+        // reports back through `didActivate`.
+        action.fulfill()
+        callProvider.reportOutgoingCall(with: action.callUUID, startedConnectingAt: nil)
     }
     
     func providerDidReset(_ provider: CXProvider) {
@@ -298,6 +479,15 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
         // First fullfill the action
         action.fulfill()
         
+        if appSettings.nativeCallEnabled {
+            // The native stack owns media in this process, so the CallKit call stays up: the
+            // controller attaches to it in `setupCallSession`.
+            endUnansweredCallTask?.cancel()
+            endCallIfLeftPending(incomingCallID)
+            actionsSubject.send(.startCall(roomID: incomingCallID.roomID, isVoiceCall: incomingCallID.isVoiceCall))
+            return
+        }
+        
         // And delay ending the call so that the app has enough time
         // to get deeplinked into
         DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
@@ -313,7 +503,7 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
         if let ongoingCallID {
             actionsSubject.send(.setAudioEnabled(!action.isMuted, roomID: ongoingCallID.roomID))
         } else {
-            MXLog.error("Failed muting/unmuting call, missing ongoingCallID")
+            MXLog.info("Ignoring a mute action without an ongoing call")
         }
         
         action.fulfill()
@@ -324,30 +514,56 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
         // This gets called for no reason on simulators, where CallKit
         // isn't even supported, ignore it.
         #else
-        if let ongoingCallID {
-            actionsSubject.send(.endCall(roomID: ongoingCallID.roomID))
-        }
-        
-        if let incomingCallID {
-            Task {
-                await sendDeclineCallEvent(incomingCallID)
-            }
-        }
-        
-        if incomingCallID?.callKitID == action.callUUID {
-            clearIncomingCallState()
-        }
-        
-        tearDownCallSession(sendEndCallAction: false)
-        
+        endCall(withCallKitID: action.callUUID)
         action.fulfill()
         #endif
     }
     
+    /// Ends the call the system identified, whether that's the ongoing one, the ringing one, or
+    /// neither because it has already been replaced.
+    ///
+    /// Kept out of the delegate method so that it's reachable on the simulator, where the provider
+    /// performs end call actions of its own and the delegate has to ignore them.
+    func endCall(withCallKitID callKitID: UUID) {
+        MXLog.info("Ending the call for \(callKitID), ongoing: \(ongoingCallID != nil), incoming: \(incomingCallID != nil)")
+        
+        // Both branches are gated on the identifier. Leaving a call to start one in another room
+        // requests an end call action for the old call and replaces `ongoingCallID` before the
+        // system gets round to performing it, so an ungated handler reads it as the new call ending
+        // and hangs up the call that was just started.
+        if let ongoingCallID, ongoingCallID.callKitID == callKitID {
+            actionsSubject.send(.endCall(roomID: ongoingCallID.roomID))
+            tearDownCallSession(sendEndCallAction: false)
+        }
+        
+        if let incomingCallID, incomingCallID.callKitID == callKitID {
+            Task {
+                await sendDeclineCallEvent(incomingCallID)
+            }
+            
+            clearIncomingCallState()
+        }
+    }
+    
     // MARK: - Private
     
+    /// Bridges the controller's completion handler, which is all ``CXCallControllerProtocol`` can
+    /// carry, back to an awaitable call.
+    private func requestTransaction(_ transaction: CXTransaction, describedAs description: String) async {
+        await withCheckedContinuation { continuation in
+            callController.request(transaction) { error in
+                if let error {
+                    MXLog.error("Failed requesting \(description) action with error: \(error)")
+                }
+                
+                continuation.resume()
+            }
+        }
+    }
+    
     private func tearDownCallSession(sendEndCallAction: Bool = true) {
         if sendEndCallAction, let ongoingCallID {
+            MXLog.info("Requesting an end call action for the ongoing call")
             let transaction = CXTransaction(action: CXEndCallAction(call: ongoingCallID.callKitID))
             callController.request(transaction) { error in
                 if let error {
@@ -405,6 +621,32 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
         }
     }
     
+    /// Ends an answered call that the native stack never took over, which nothing else would: the
+    /// call is deliberately left up for the controller to attach to in `setupCallSession`.
+    private func endCallIfLeftPending(_ callID: CallID) {
+        answeredNativeCallID = callID
+        
+        endPendingCallTask = Task { [weak self] in
+            try? await self?.timeProvider.clock.sleep(for: .seconds(30))
+            
+            guard let self, !Task.isCancelled, answeredNativeCallID == callID else {
+                return
+            }
+            
+            MXLog.error("The native call stack never took over the answered call, ending it")
+            endPendingCall()
+        }
+    }
+    
+    private func endPendingCall() {
+        guard let answeredNativeCallID else {
+            return
+        }
+        
+        callProvider.reportCall(with: answeredNativeCallID.callKitID, endedAt: nil, reason: .failed)
+        clearIncomingCallState()
+    }
+    
     private func sendDeclineCallEvent(_ incomingCallID: CallID) async {
         guard let rtcNotificationID = incomingCallID.rtcNotificationID else {
             MXLog.info("No rtc notification event to decline.")
@@ -506,6 +748,9 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
     private func clearIncomingCallState() {
         endUnansweredCallTask?.cancel()
         endUnansweredCallTask = nil
+        endPendingCallTask?.cancel()
+        endPendingCallTask = nil
+        answeredNativeCallID = nil
         declineListenerHandle?.cancel()
         declineListenerHandle = nil
         incomingCallRoomInfoCancellable = nil

NSE/Sources/NotificationHandler.swift

@@ -273,8 +273,8 @@ nonisolated class NotificationHandler {
     /// Asks the push gateway to deliver a PushKit push with the call details, the way the legacy
     /// element-ios app did. The app's `PKPushRegistryDelegate` then reports the call to CallKit.
     private func requestVoIPPush(roomID: String, roomDisplayName: String, rtcNotifyEventID: String, expirationDate: Date, isVoiceCall: Bool) async {
-        guard let token = settings.pushKitDeviceToken,
-              let notifyURL = settings.voipPushGatewayNotifyURL.flatMap(URL.init(string:)) else {
+        guard let token = userSettings.app.pushKitDeviceToken,
+              let notifyURL = userSettings.app.voipPushGatewayNotifyURL.flatMap(URL.init(string:)) else {
             MXLog.warning("No PushKit token or push gateway stored by the app, cannot request a VoIP push")
             return
         }
@@ -288,7 +288,7 @@ nonisolated class NotificationHandler {
         let body: [String: Any] = ["notification": ["event_id": rtcNotifyEventID,
                                                     "room_id": roomID,
                                                     "prio": "high",
-                                                    "devices": [["app_id": settings.voipPusherAppID,
+                                                    "devices": [["app_id": userSettings.app.voipPusherAppID,
                                                                  "pushkey": token,
                                                                  "data": ["format": "event_id_only",
                                                                           "default_payload": defaultPayload]]]]]