Notification: ensure that a notification is displayed when a Push cannot be resolved.

Previously the error was logged and added to push history but no notification was shown, so the user fully miss the new message.

Author: bmarty

libraries/matrix/api/src/main/kotlin/io/element/android/libraries/matrix/api/notification/NotificationData.kt

@@ -68,6 +68,7 @@ sealed interface NotificationContent {
         ) : MessageLike
 
         data object RoomEncrypted : MessageLike
+        data object UnableToResolve : MessageLike
         data class RoomMessage(
             val senderId: UserId,
             val messageType: MessageType

libraries/matrix/impl/src/main/kotlin/io/element/android/libraries/matrix/impl/notification/RustNotificationService.kt

@@ -12,6 +12,7 @@ import io.element.android.libraries.core.extensions.runCatchingExceptions
 import io.element.android.libraries.matrix.api.core.EventId
 import io.element.android.libraries.matrix.api.core.RoomId
 import io.element.android.libraries.matrix.api.core.SessionId
+import io.element.android.libraries.matrix.api.notification.NotificationContent
 import io.element.android.libraries.matrix.api.notification.NotificationData
 import io.element.android.libraries.matrix.api.notification.NotificationService
 import io.element.android.services.toolbox.api.systemclock.SystemClock
@@ -24,7 +25,7 @@ class RustNotificationService(
     private val sessionId: SessionId,
     private val notificationClient: NotificationClient,
     private val dispatchers: CoroutineDispatchers,
-    clock: SystemClock,
+    private val clock: SystemClock,
 ) : NotificationService {
     private val notificationMapper: NotificationMapper = NotificationMapper(clock)
 
@@ -43,11 +44,32 @@ class RustNotificationService(
                 val eventIds = requests.flatMap { it.eventIds }
                 for (eventId in eventIds) {
                     val item = items[eventId]
+                    val roomId = RoomId(requests.find { it.eventIds.contains(eventId) }?.roomId!!)
                     if (item != null) {
-                        val roomId = RoomId(requests.find { it.eventIds.contains(eventId) }?.roomId!!)
                         put(EventId(eventId), notificationMapper.map(sessionId, EventId(eventId), roomId, item))
                     } else {
                         Timber.e("Could not retrieve event for notification with $eventId")
+                        put(
+                            EventId(eventId),
+                            NotificationData(
+                                sessionId = sessionId,
+                                eventId = EventId(eventId),
+                                threadId = null,
+                                roomId = roomId,
+                                senderAvatarUrl = null,
+                                senderDisplayName = null,
+                                senderIsNameAmbiguous = false,
+                                roomAvatarUrl = null,
+                                roomDisplayName = null,
+                                isDirect = false,
+                                isDm = false,
+                                isEncrypted = false,
+                                isNoisy = false,
+                                timestamp = clock.epochMillis(),
+                                content = NotificationContent.MessageLike.UnableToResolve,
+                                hasMention = false
+                            )
+                        )
                     }
                 }
             }

libraries/push/impl/src/main/kotlin/io/element/android/libraries/push/impl/notifications/DefaultNotifiableEventResolver.kt

@@ -225,6 +225,11 @@ class DefaultNotifiableEventResolver @Inject constructor(
                 val fallbackNotifiableEvent = fallbackNotifiableEvent(userId, roomId, eventId)
                 ResolvedPushEvent.Event(fallbackNotifiableEvent)
             }
+            NotificationContent.MessageLike.UnableToResolve -> {
+                Timber.tag(loggerTag.value).w("Unable to resolve notification -> fallback")
+                val fallbackNotifiableEvent = fallbackNotifiableEvent(userId, roomId, eventId)
+                ResolvedPushEvent.Event(fallbackNotifiableEvent)
+            }
             is NotificationContent.MessageLike.RoomRedaction -> {
                 // Note: this case will be handled below
                 val redactedEventId = content.redactedEventId

libraries/push/impl/src/main/kotlin/io/element/android/libraries/push/impl/push/DefaultPushHandler.kt

@@ -25,6 +25,7 @@ import io.element.android.libraries.push.impl.history.onUnableToRetrieveSession
 import io.element.android.libraries.push.impl.notifications.NotificationEventRequest
 import io.element.android.libraries.push.impl.notifications.NotificationResolverQueue
 import io.element.android.libraries.push.impl.notifications.channels.NotificationChannels
+import io.element.android.libraries.push.impl.notifications.model.FallbackNotifiableEvent
 import io.element.android.libraries.push.impl.notifications.model.NotifiableEvent
 import io.element.android.libraries.push.impl.notifications.model.NotifiableRingingCallEvent
 import io.element.android.libraries.push.impl.notifications.model.ResolvedPushEvent
@@ -87,13 +88,24 @@ class DefaultPushHandler @Inject constructor(
                     } else {
                         result.fold(
                             onSuccess = {
-                                pushHistoryService.onSuccess(
-                                    providerInfo = request.providerInfo,
-                                    eventId = request.eventId,
-                                    roomId = request.roomId,
-                                    sessionId = request.sessionId,
-                                    comment = "Push handled successfully",
-                                )
+                                if (it is ResolvedPushEvent.Event && it.notifiableEvent is FallbackNotifiableEvent) {
+                                    pushHistoryService.onUnableToResolveEvent(
+                                        providerInfo = request.providerInfo,
+                                        eventId = request.eventId,
+                                        roomId = request.roomId,
+                                        sessionId = request.sessionId,
+                                        reason = "Unable to resolve event, showing fallback notification",
+                                    )
+                                    mutableBatteryOptimizationStore.showBatteryOptimizationBanner()
+                                } else {
+                                    pushHistoryService.onSuccess(
+                                        providerInfo = request.providerInfo,
+                                        eventId = request.eventId,
+                                        roomId = request.roomId,
+                                        sessionId = request.sessionId,
+                                        comment = "Push handled successfully",
+                                    )
+                                }
                             },
                             onFailure = { exception ->
                                 pushHistoryService.onUnableToResolveEvent(