Fixes #3042 - Cancel ElementCall ringing as soon as the call ends

ElementX/Sources/Services/ElementCall/ElementCallService.swift

@@ -44,7 +44,17 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
         return CXProvider(configuration: configuration)
     }()
     
-    private var incomingCallID: CallID?
+    private weak var clientProxy: ClientProxyProtocol?
+    
+    private var cancellables = Set<AnyCancellable>()
+    private var incomingCallID: CallID? {
+        didSet {
+            Task {
+                await observeIncomingCallRoomStateUpdates()
+            }
+        }
+    }
+    
     private var endUnansweredCallTask: Task<Void, Never>?
     
     private var ongoingCallID: CallID?
@@ -65,6 +75,10 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
         callProvider.setDelegate(self, queue: nil)
     }
     
+    func setClientProxy(_ clientProxy: any ClientProxyProtocol) {
+        self.clientProxy = clientProxy
+    }
+    
     func setupCallSession(roomID: String, roomDisplayName: String) async {
         // Drop any ongoing calls when starting a new one
         if ongoingCallID != nil {
@@ -221,4 +235,46 @@ class ElementCallService: NSObject, ElementCallServiceProtocol, PKPushRegistryDe
         
         ongoingCallID = nil
     }
+    
+    func observeIncomingCallRoomStateUpdates() async {
+        cancellables.removeAll()
+        
+        guard let clientProxy, let incomingCallID else {
+            return
+        }
+        
+        guard let roomProxy = await clientProxy.roomForIdentifier(incomingCallID.roomID) else {
+            return
+        }
+        
+        roomProxy.subscribeToRoomInfoUpdates()
+        
+        // There's no incoming event for call cancellations so try to infer
+        // it from what we have. If the call is running before subscribing then wait
+        // for it to change to `false` otherwise wait for it to turn `true` before
+        // changing to `false`
+        let isCallOngoing = roomProxy.hasOngoingCall
+        
+        roomProxy
+            .actionsPublisher
+            .map { action in
+                switch action {
+                case .roomInfoUpdate:
+                    return roomProxy.hasOngoingCall
+                }
+            }
+            .removeDuplicates()
+            .dropFirst(isCallOngoing ? 0 : 1)
+            .sink { [weak self] hasOngoingCall in
+                guard let self else { return }
+                
+                if !hasOngoingCall {
+                    MXLog.info("Call has been cancelled")
+                    cancellables.removeAll()
+                    endUnansweredCallTask?.cancel()
+                    callProvider.reportCall(with: incomingCallID.callKitID, endedAt: nil, reason: .remoteEnded)
+                }
+            }
+            .store(in: &cancellables)
+    }
 }

ElementX/Sources/Services/ElementCall/ElementCallServiceConstants.swift

@@ -0,0 +1,24 @@
+//
+// Copyright 2024 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Foundation
+
+enum ElementCallServiceNotificationKey: String {
+    case roomID
+    case roomDisplayName
+}
+
+let ElementCallServiceNotificationDiscardDelta = 10.0

ElementX/Sources/Services/ElementCall/ElementCallServiceProtocol.swift

@@ -22,17 +22,12 @@ enum ElementCallServiceAction {
     case setCallMuted(_ muted: Bool, roomID: String)
 }
 
-enum ElementCallServiceNotificationKey: String {
-    case roomID
-    case roomDisplayName
-}
-
-let ElementCallServiceNotificationDiscardDelta = 10.0
-
 // sourcery: AutoMockable
 protocol ElementCallServiceProtocol {
     var actions: AnyPublisher<ElementCallServiceAction, Never> { get }
     
+    func setClientProxy(_ clientProxy: ClientProxyProtocol)
+    
     func setupCallSession(roomID: String, roomDisplayName: String) async
     
     func tearDownCallSession()