[Amazon] StopConnect for UDC in Android tv-casting-app

Updated native layer and iOS tv-casting-app to use native layer
ConnectionState instead of a pendingPasscode customer check.

Changes
* Expose native layer ConnectionState to iOS tv-casting-app
* Update iOS tv-casting-app to use ConnectionState to determine if we
  should call stopConnect()
* Only call stopConnect() on navigate back from ConnectionExampleView
* Updated doc to indicate when a object method will free itself as a
  side effect

Test
1. Manually verified UDC attempt is successful both Android iOS for following
   1. Attempt UDC attempt (both commissionee & commissioner generated passcode)
   2. Navigate back to discovery page
   3. Start new UDC attempt (both commissionee & commissioner generated passcode)

2. Manually verified UDC attempt is successful both Android iOS for following. UDC will finish in the background.
   1. Attempt UDC attempt (both commissionee & commissioner generated passcode)
   2. Confirm passcode on TV app or casting app depending on who
      generated passcode
   3. Navigate back before commission fnishes.

3. Manual regression test following
   * UDC attempt happy path (no navigate back) for both commissinee &
     commissioner generated passcode

Author: yuenton-amazon

examples/tv-casting-app/darwin/MatterTvCastingBridge/MatterTvCastingBridge/MCCastingPlayer.h

@@ -26,6 +26,16 @@
 
 @class MCEndpoint;
 
+/**
+ * @brief Represents CastingPlayer ConnectionState.
+ * @note Should be kept up to date with matter::casting::core::ConnectionState.
+ */
+typedef enum {
+    MC_CASTING_PLAYER_NOT_CONNECTED,
+    MC_CASTING_PLAYER_CONNECTING,
+    MC_CASTING_PLAYER_CONNECTED,
+} MCCastingPlayerConnectionState;
+
 /**
  * @brief MCCastingPlayer represents a Matter commissioner that is able to play media to a physical
  * output or to a display screen which is part of the device.
@@ -149,9 +159,11 @@
 - (void)disconnect;
 
 /**
- * @return true if this CastingPlayer is still pending pass code from user and therefore is not ready
+ * @brief Get the CastingPlayer's connection state
+ * @param state The current connection state that will be return.
+ * @return nil if request submitted successfully, otherwise a NSError object corresponding to the error.
  */
-- (bool)isPendingPasscodeFromUser;
+- (NSError * _Nullable)getConnectionState:(MCCastingPlayerConnectionState * _Nonnull)state;
 
 - (NSString * _Nonnull)identifier;
 - (NSString * _Nonnull)deviceName;

examples/tv-casting-app/darwin/MatterTvCastingBridge/MatterTvCastingBridge/MCCastingPlayer.mm

@@ -190,18 +190,33 @@ - (void)disconnect
     });
 }
 
-- (bool)isPendingPasscodeFromUser
+- (NSError * _Nullable)getConnectionState:(MCCastingPlayerConnectionState * _Nonnull)state;
 {
-    ChipLogProgress(AppServer, "MCCastingPlayer.isPendingPasscodeFromUser() called");
-    VerifyOrReturnValue([[MCCastingApp getSharedInstance] isRunning], false, ChipLogError(AppServer, "MCCastingPlayer.isPendingPasscodeFromUser() MCCastingApp NOT running"));
+    ChipLogProgress(AppServer, "MCCastingPlayer.getConnectionState() called");
+    VerifyOrReturnValue([[MCCastingApp getSharedInstance] isRunning], [MCErrorUtils NSErrorFromChipError:CHIP_ERROR_INCORRECT_STATE], ChipLogError(AppServer, "MCCastingPlayer.getConnectionState() MCCastingApp NOT running"));
 
+    __block matter::casting::core::ConnectionState native_state = matter::casting::core::ConnectionState::CASTING_PLAYER_NOT_CONNECTED;
     dispatch_queue_t workQueue = [[MCCastingApp getSharedInstance] getWorkQueue];
-    
-    __block bool isPending = false;
     dispatch_sync(workQueue, ^{
-        isPending = _cppCastingPlayer->IsPendingPasscodeFromUser();
+        native_state = _cppCastingPlayer->GetConnectionState();
     });
-    return isPending;
+
+    switch (native_state) {
+    case matter::casting::core::ConnectionState::CASTING_PLAYER_NOT_CONNECTED:
+        *state = MC_CASTING_PLAYER_NOT_CONNECTED;
+        break;
+    case matter::casting::core::ConnectionState::CASTING_PLAYER_CONNECTING:
+        *state = MC_CASTING_PLAYER_CONNECTING;
+        break;
+    case matter::casting::core::ConnectionState::CASTING_PLAYER_CONNECTED:
+        *state = MC_CASTING_PLAYER_CONNECTED;
+        break;
+    default:
+        [NSException raise:@"Unhandled matter::casting::core::ConnectionState" format:@"%d is not handled", native_state];
+        break;
+    }
+
+    return nil;
 }
 
 - (instancetype _Nonnull)initWithCppCastingPlayer:(matter::casting::memory::Strong<matter::casting::core::CastingPlayer>)cppCastingPlayer

examples/tv-casting-app/darwin/TvCasting/TvCasting/MCConnectionExampleViewModel.swift

@@ -44,9 +44,13 @@ class MCConnectionExampleViewModel: ObservableObject {
 
     func cancelConnectionAttempt(selectedCastingPlayer: MCCastingPlayer?) {
         DispatchQueue.main.async {
-            // Only stop connection if we are pending passcode confirmation
-            if selectedCastingPlayer?.isPendingPasscodeFromUser() == true {
+            var connectionState = MC_CASTING_PLAYER_NOT_CONNECTED;
+            let err = selectedCastingPlayer?.getConnectionState(&connectionState);
+
+            // Only stop connection if we are still connecting to the device
+            if err == nil && connectionState == MC_CASTING_PLAYER_CONNECTING {
                 self.Log.info("MCConnectionExampleViewModel cancelConnect(). User navigating back from ConnectionView")
+                // NOTE, once stopConnecting() is called, the targetCastingPlayer's native object is freed
                 let err = selectedCastingPlayer?.stopConnecting()
                 if err == nil {
                     self.connectionStatus = "User cancelled the connection attempt with CastingPlayer.stopConnecting()."
@@ -125,17 +129,9 @@ class MCConnectionExampleViewModel: ObservableObject {
                                 dataSource.update(newCommissionableData)
                                 self.Log.info("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, Updated MCAppParametersDataSource instance with new MCCommissionableData.")
                             } else {
-                                self.Log.error("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, InitializationExample.getAppParametersDataSource() failed, calling stopConnecting()")
-                                self.connectionStatus = "Failed to update the MCAppParametersDataSource with the user entered passcode: \n\nRoute back and try again."
+                                self.Log.error("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, InitializationExample.getAppParametersDataSource() failed")
+                                self.connectionStatus = "Failed to update the MCAppParametersDataSource with the user entered passcode: \n\nRoute back to disconnect and try again."
                                 self.connectionSuccess = false
-                                // Since we failed to update the passcode, Attempt to cancel the connection attempt with
-                                // the CastingPlayer/Commissioner.
-                                let err = selectedCastingPlayer?.stopConnecting()
-                                if err == nil {
-                                    self.Log.info("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, InitializationExample.getAppParametersDataSource() failed, then stopConnecting() succeeded")
-                                } else {
-                                    self.Log.error("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, InitializationExample.getAppParametersDataSource() failed, then stopConnecting() failed due to: \(err)")
-                                }
                                 return
                             }
 
@@ -144,28 +140,13 @@ class MCConnectionExampleViewModel: ObservableObject {
                             if errContinue == nil {
                                 self.connectionStatus = "Continuing to connect with user entered passcode: \(userEnteredPasscode)"
                             } else {
-                                self.connectionStatus = "Continue Connecting to Casting Player failed with: \(String(describing: errContinue)) \n\nRoute back and try again."
+                                self.connectionStatus = "Continue Connecting to Casting Player failed with: \(String(describing: errContinue)) \n\nRoute back to disconnect and try again."
                                 self.Log.error("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, MCCastingPlayer.continueConnecting() failed due to: \(errContinue)")
-                                // Since continueConnecting() failed, Attempt to cancel the connection attempt with
-                                // the CastingPlayer/Commissioner.
-                                let err = selectedCastingPlayer?.stopConnecting()
-                                if err == nil {
-                                    self.Log.info("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, MCCastingPlayer.continueConnecting() failed, then stopConnecting() succeeded")
-                                } else {
-                                    self.Log.error("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, MCCastingPlayer.continueConnecting() failed, then stopConnecting() failed due to: \(err)")
-                                }
                             }
                         }, cancelConnecting: {
-                            self.Log.info("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, Connection attempt cancelled by the user, calling MCCastingPlayer.stopConnecting()")
-                            let err = selectedCastingPlayer?.stopConnecting()
+                            self.Log.info("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, Connection attempt cancelled by the user")
                             self.connectionSuccess = false
-                            if err == nil {
-                                self.connectionStatus = "User cancelled the connection attempt with CastingPlayer. \n\nRoute back to exit."
-                                self.Log.info("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, User cancelled the connection attempt with MCCastingPlayer, MCCastingPlayer.stopConnecting() succeeded.")
-                            } else {
-                                self.connectionStatus = "Cancel connection failed due to: \(String(describing: err)) \n\nRoute back to exit."
-                                self.Log.error("MCConnectionExampleViewModel connect() commissionerDeclarationCallback, MCCastingPlayer.stopConnecting() failed due to: \(err)")
-                            }
+                            self.connectionStatus = "User cancelled the connection attempt with CastingPlayer. \n\nRoute back to disconnect & exit."
                         })
                     }
                 }

examples/tv-casting-app/tv-casting-common/core/CastingPlayer.h

@@ -218,11 +218,15 @@ class CastingPlayer : public std::enable_shared_from_this<CastingPlayer>
      * otherwise. StopConnecting() can only be called by the client during the CastingPlayer/Commissioner-Generated passcode
      * commissioning flow. Calling StopConnecting() during the Client/Commissionee-Generated commissioning flow will return a
      * CHIP_ERROR_INCORRECT_STATE error.
+     *
+     * @note This method will free the calling object as a side effect.
      */
     CHIP_ERROR StopConnecting();
 
     /**
      * @brief Sets the internal connection state of this CastingPlayer to "disconnected"
+     *
+     * @note This method will free the calling object as a side effect.
      */
     void Disconnect();
 
@@ -286,7 +290,11 @@ class CastingPlayer : public std::enable_shared_from_this<CastingPlayer>
     /**
      * @brief Return the current state of the CastingPlayer
      */
-    ConnectionState GetConnectionState() const { return mConnectionState; }
+    ConnectionState GetConnectionState() const
+    {
+        ChipLogError(AppServer, "CastingPlayer::GetConnectionState() state: %d", mConnectionState);
+        return mConnectionState;
+    }
 
 private:
     std::vector<memory::Strong<Endpoint>> mEndpoints;
@@ -326,6 +334,8 @@ class CastingPlayer : public std::enable_shared_from_this<CastingPlayer>
     /**
      * @brief resets this CastingPlayer's state and calls mOnCompleted with the CHIP_ERROR. Also, after calling mOnCompleted, it
      * clears mOnCompleted by setting it to a nullptr.
+     *
+     * @note This method will free the calling object as a side effect.
      */
     void resetState(CHIP_ERROR err);
 

examples/tv-casting-app/tv-casting-common/core/CastingPlayerDiscovery.h

@@ -108,6 +108,7 @@ class CastingPlayerDiscovery
     static CastingPlayerDiscovery * GetInstance();
     ~CastingPlayerDiscovery()
     {
+        ChipLogError(AppServer, "CastingPlayerDiscovery destructor() called");
         mCastingPlayers.clear();
         mCastingPlayersInternal.clear();
     }

examples/tv-casting-app/tv-casting-common/support/ChipDeviceEventHandler.cpp

@@ -37,6 +37,18 @@ void ChipDeviceEventHandler::Handle(const chip::DeviceLayer::ChipDeviceEvent * e
 {
     ChipLogProgress(AppServer, "ChipDeviceEventHandler::Handle() called");
 
+    // Make sure we have not disconnected from the TargetCastingPlayer when handling incoming messages.
+    // Sometimes the tv-app will still send messages after we clean up the TargetCastingPlayer.
+    // Exmaple: Call stopConnecting() after immediately after calling continueConnectiong()
+    //
+    // A proper fix would be to either not let user navigate back when running post commission or update commissioner, commissionee
+    // communication protocal to better handle asynchronous disconnects
+    if (CastingPlayer::GetTargetCastingPlayer() == nullptr)
+    {
+        ChipLogError(AppServer, "ChipDeviceEventHandler::Handler() TargetCastingPlayer is null for event: %u", event->Type);
+        return;
+    }
+
     bool runPostCommissioning           = false;
     chip::NodeId targetNodeId           = 0;
     chip::FabricIndex targetFabricIndex = 0;