Sync on push : call startSync/stopSync

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

@@ -18,9 +18,6 @@ package io.element.android.libraries.push.impl.push
 
 import com.squareup.anvil.annotations.ContributesBinding
 import io.element.android.libraries.di.AppScope
-import io.element.android.libraries.featureflag.api.FeatureFlagService
-import io.element.android.libraries.featureflag.api.FeatureFlags
-import io.element.android.libraries.matrix.api.MatrixClientProvider
 import io.element.android.libraries.push.impl.notifications.DefaultNotificationDrawerManager
 import io.element.android.libraries.push.impl.notifications.model.NotifiableEvent
 import kotlinx.coroutines.CoroutineScope
@@ -35,23 +32,12 @@ interface OnNotifiableEventReceived {
 class DefaultOnNotifiableEventReceived @Inject constructor(
     private val defaultNotificationDrawerManager: DefaultNotificationDrawerManager,
     private val coroutineScope: CoroutineScope,
-    private val matrixClientProvider: MatrixClientProvider,
-    private val featureFlagService: FeatureFlagService,
+    private val syncOnNotifiableEvent: SyncOnNotifiableEvent,
 ) : OnNotifiableEventReceived {
     override fun onNotifiableEventReceived(notifiableEvent: NotifiableEvent) {
         coroutineScope.launch {
-            subscribeToRoomIfNeeded(notifiableEvent)
+            launch { syncOnNotifiableEvent(notifiableEvent) }
             defaultNotificationDrawerManager.onNotifiableEventReceived(notifiableEvent)
         }
     }
-
-    private fun CoroutineScope.subscribeToRoomIfNeeded(notifiableEvent: NotifiableEvent) = launch {
-        if (!featureFlagService.isFeatureEnabled(FeatureFlags.SyncOnPush)) {
-            return@launch
-        }
-        val client = matrixClientProvider.getOrRestore(notifiableEvent.sessionId).getOrNull() ?: return@launch
-        client.getRoom(notifiableEvent.roomId)?.use { room ->
-            room.subscribeToSync()
-        }
-    }
 }

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

@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 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
+ *
+ *     https://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.
+ */
+
+package io.element.android.libraries.push.impl.push
+
+import io.element.android.libraries.core.coroutine.CoroutineDispatchers
+import io.element.android.libraries.featureflag.api.FeatureFlagService
+import io.element.android.libraries.featureflag.api.FeatureFlags
+import io.element.android.libraries.matrix.api.MatrixClientProvider
+import io.element.android.libraries.matrix.api.core.EventId
+import io.element.android.libraries.matrix.api.room.MatrixRoom
+import io.element.android.libraries.matrix.api.sync.SyncService
+import io.element.android.libraries.matrix.api.timeline.MatrixTimelineItem
+import io.element.android.libraries.push.impl.notifications.model.NotifiableEvent
+import io.element.android.services.appnavstate.api.AppForegroundStateService
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.withContext
+import kotlinx.coroutines.withTimeoutOrNull
+import java.util.concurrent.atomic.AtomicInteger
+import javax.inject.Inject
+import kotlin.time.Duration
+import kotlin.time.Duration.Companion.seconds
+
+class SyncOnNotifiableEvent @Inject constructor(
+    private val matrixClientProvider: MatrixClientProvider,
+    private val featureFlagService: FeatureFlagService,
+    private val appForegroundStateService: AppForegroundStateService,
+    private val dispatchers: CoroutineDispatchers,
+) {
+    private var syncCounter = AtomicInteger(0)
+
+    suspend operator fun invoke(notifiableEvent: NotifiableEvent) = withContext(dispatchers.io) {
+        if (!featureFlagService.isFeatureEnabled(FeatureFlags.SyncOnPush)) {
+            return@withContext
+        }
+        val client = matrixClientProvider.getOrRestore(notifiableEvent.sessionId).getOrNull() ?: return@withContext
+        client.getRoom(notifiableEvent.roomId)?.use { room ->
+            room.subscribeToSync()
+
+            // If the app is in foreground, sync is already running, so just add the subscription.
+            if (!appForegroundStateService.isInForeground.value) {
+                val syncService = client.syncService()
+                syncService.startSyncIfNeeded()
+                room.waitsUntilEventIsKnown(eventId = notifiableEvent.eventId, timeout = 10.seconds)
+                syncService.stopSyncIfNeeded()
+            }
+        }
+    }
+
+    private suspend fun MatrixRoom.waitsUntilEventIsKnown(eventId: EventId, timeout: Duration) {
+        withTimeoutOrNull(timeout) {
+            liveTimeline.timelineItems.first { timelineItems ->
+                timelineItems.any { timelineItem ->
+                    when (timelineItem) {
+                        is MatrixTimelineItem.Event -> timelineItem.eventId == eventId
+                        else -> false
+                    }
+                }
+            }
+        }
+    }
+
+    private suspend fun SyncService.startSyncIfNeeded() {
+        if (syncCounter.getAndIncrement() == 0) {
+            startSync()
+        }
+    }
+
+    private suspend fun SyncService.stopSyncIfNeeded() {
+        if (syncCounter.decrementAndGet() == 0 && !appForegroundStateService.isInForeground.value) {
+            stopSync()
+        }
+    }
+}