Backend triggered sync

Change-Id: I53c43b136ebb755f6258b1e815301dddb3b536a3

core/data/build.gradle.kts

@@ -36,6 +36,7 @@ dependencies {
     implementation(project(":core:datastore"))
     implementation(project(":core:model"))
     implementation(project(":core:network"))
+    implementation(project(":core:notifications"))
     implementation(libs.androidx.core.ktx)
     implementation(libs.kotlinx.coroutines.android)
     implementation(libs.kotlinx.datetime)

core/data/src/main/java/com/google/samples/apps/nowinandroid/core/data/repository/OfflineFirstNewsRepository.kt

@@ -30,7 +30,9 @@ import com.google.samples.apps.nowinandroid.core.datastore.ChangeListVersions
 import com.google.samples.apps.nowinandroid.core.model.data.NewsResource
 import com.google.samples.apps.nowinandroid.core.network.NiaNetworkDataSource
 import com.google.samples.apps.nowinandroid.core.network.model.NetworkNewsResource
+import com.google.samples.apps.nowinandroid.core.notifications.Notifier
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.map
 import javax.inject.Inject
 
@@ -46,6 +48,7 @@ class OfflineFirstNewsRepository @Inject constructor(
     private val newsResourceDao: NewsResourceDao,
     private val topicDao: TopicDao,
     private val network: NiaNetworkDataSource,
+    private val notifier: Notifier,
 ) : NewsRepository {
 
     override fun getNewsResources(
@@ -69,6 +72,16 @@ class OfflineFirstNewsRepository @Inject constructor(
             },
             modelDeleter = newsResourceDao::deleteNewsResources,
             modelUpdater = { changedIds ->
+                // TODO: Make this more efficient, there is no need to retrieve populated
+                //  news resources when all that's needed are the ids
+                val existingNewsResourceIds = newsResourceDao.getNewsResources(
+                    useFilterNewsIds = true,
+                    filterNewsIds = changedIds.toSet(),
+                )
+                    .first()
+                    .map { it.entity.id }
+                    .toSet()
+
                 changedIds.chunked(SYNC_BATCH_SIZE).forEach { chunkedIds ->
                     val networkNewsResources = network.getNewsResources(ids = chunkedIds)
 
@@ -92,6 +105,20 @@ class OfflineFirstNewsRepository @Inject constructor(
                             .flatten(),
                     )
                 }
+
+                val addedNewsResources = newsResourceDao.getNewsResources(
+                    useFilterNewsIds = true,
+                    filterNewsIds = changedIds.toSet(),
+                )
+                    .first()
+                    .filter { !existingNewsResourceIds.contains(it.entity.id) }
+                    .map(PopulatedNewsResource::asExternalModel)
+
+                // TODO: Define business logic for notifications on first time sync.
+                //  we probably do not want to send notifications on first install.
+                //  We can easily check if the change list version is 0 and not send notifications
+                // if it is.
+                if (addedNewsResources.isNotEmpty()) notifier.onNewsAdded(addedNewsResources)
             },
         )
 }

core/data/src/main/java/com/google/samples/apps/nowinandroid/core/data/util/SyncManager.kt

@@ -21,6 +21,7 @@ import kotlinx.coroutines.flow.Flow
 /**
  * Reports on if synchronization is in progress
  */
-interface SyncStatusMonitor {
+interface SyncManager {
     val isSyncing: Flow<Boolean>
+    fun requestSync()
 }

core/data/src/test/java/com/google/samples/apps/nowinandroid/core/data/repository/OfflineFirstNewsRepositoryTest.kt

@@ -36,6 +36,7 @@ import com.google.samples.apps.nowinandroid.core.datastore.test.testUserPreferen
 import com.google.samples.apps.nowinandroid.core.model.data.NewsResource
 import com.google.samples.apps.nowinandroid.core.network.model.NetworkChangeList
 import com.google.samples.apps.nowinandroid.core.network.model.NetworkNewsResource
+import com.google.samples.apps.nowinandroid.core.testing.notifications.TestNotifier
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.test.TestScope
 import kotlinx.coroutines.test.UnconfinedTestDispatcher
@@ -58,6 +59,8 @@ class OfflineFirstNewsRepositoryTest {
 
     private lateinit var network: TestNiaNetworkDataSource
 
+    private lateinit var notifier: TestNotifier
+
     private lateinit var synchronizer: Synchronizer
 
     @get:Rule
@@ -68,6 +71,7 @@ class OfflineFirstNewsRepositoryTest {
         newsResourceDao = TestNewsResourceDao()
         topicDao = TestTopicDao()
         network = TestNiaNetworkDataSource()
+        notifier = TestNotifier()
         synchronizer = TestSynchronizer(
             NiaPreferencesDataSource(
                 tmpFolder.testUserPreferencesDataStore(testScope),
@@ -78,6 +82,7 @@ class OfflineFirstNewsRepositoryTest {
             newsResourceDao = newsResourceDao,
             topicDao = topicDao,
             network = network,
+            notifier = notifier,
         )
     }
 
@@ -145,6 +150,12 @@ class OfflineFirstNewsRepositoryTest {
                 expected = network.latestChangeListVersion(CollectionType.NewsResources),
                 actual = synchronizer.getChangeListVersions().newsResourceVersion,
             )
+
+            // Notifier should have been called with new news resources
+            assertEquals(
+                expected = newsResourcesFromDb.map(NewsResource::id).sorted(),
+                actual = notifier.addedNewsResources.first().map(NewsResource::id).sorted(),
+            )
         }
 
     @Test
@@ -186,6 +197,13 @@ class OfflineFirstNewsRepositoryTest {
                 expected = network.latestChangeListVersion(CollectionType.NewsResources),
                 actual = synchronizer.getChangeListVersions().newsResourceVersion,
             )
+
+            // Notifier should have been called with news resources from network that are not
+            // deleted
+            assertEquals(
+                expected = (newsResourcesFromNetwork.map(NewsResource::id) - deletedItems).sorted(),
+                actual = notifier.addedNewsResources.first().map(NewsResource::id).sorted(),
+            )
         }
 
     @Test
@@ -225,6 +243,12 @@ class OfflineFirstNewsRepositoryTest {
                 expected = changeList.last().changeListVersion,
                 actual = synchronizer.getChangeListVersions().newsResourceVersion,
             )
+
+            // Notifier should have been called with only added news resources from network
+            assertEquals(
+                expected = newsResourcesFromNetwork.map(NewsResource::id).sorted(),
+                actual = notifier.addedNewsResources.first().map(NewsResource::id).sorted(),
+            )
         }
 
     @Test

core/notifications/.gitignore

@@ -0,0 +1 @@
+/build

core/notifications/build.gradle.kts

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * 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.
+ */
+plugins {
+    id("nowinandroid.android.library")
+    id("nowinandroid.android.library.compose")
+    id("nowinandroid.android.hilt")
+}
+
+android {
+    namespace = "com.google.samples.apps.nowinandroid.core.notifications"
+}
+
+dependencies {
+    implementation(project(":core:model"))
+
+    implementation(libs.kotlinx.coroutines.android)
+    implementation(libs.androidx.compose.runtime)
+    implementation(libs.androidx.core.ktx)
+
+    implementation(platform(libs.firebase.bom))
+    implementation(libs.firebase.cloud.messaging)
+}

core/notifications/src/demo/java/com/google/samples/apps/nowinandroid/core/notifications/NotificationsModule.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * 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 com.google.samples.apps.nowinandroid.core.notifications
+
+import dagger.Binds
+import dagger.Module
+import dagger.hilt.InstallIn
+import dagger.hilt.components.SingletonComponent
+
+@Module
+@InstallIn(SingletonComponent::class)
+abstract class NotificationsModule {
+    @Binds
+    abstract fun bindNotifier(
+        notifier: NoOpNotifier,
+    ): Notifier
+}

core/notifications/src/main/AndroidManifest.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright 2023 The Android Open Source Project
+
+     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.
+-->
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"/>

core/notifications/src/main/java/com/google/samples/apps/nowinandroid/core/notifications/AndroidSystemNotifier.kt

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * 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 com.google.samples.apps.nowinandroid.core.notifications
+
+import com.google.samples.apps.nowinandroid.core.model.data.NewsResource
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Implementation of [Notifier] that displays notifications in the system tray.
+ */
+@Singleton
+class AndroidSystemNotifier @Inject constructor() : Notifier {
+
+    override fun onNewsAdded(newsResources: List<NewsResource>) {
+        // TODO, create notification and display to the user
+    }
+}

core/notifications/src/main/java/com/google/samples/apps/nowinandroid/core/notifications/NoOpNotifier.kt

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * 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 com.google.samples.apps.nowinandroid.core.notifications
+
+import com.google.samples.apps.nowinandroid.core.model.data.NewsResource
+import javax.inject.Inject
+
+/**
+ * Implementation of [Notifier] which does nothing. Useful for tests and previews.
+ */
+class NoOpNotifier @Inject constructor() : Notifier {
+    override fun onNewsAdded(newsResources: List<NewsResource>) = Unit
+}

core/notifications/src/main/java/com/google/samples/apps/nowinandroid/core/notifications/Notifier.kt

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * 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 com.google.samples.apps.nowinandroid.core.notifications
+
+import com.google.samples.apps.nowinandroid.core.model.data.NewsResource
+
+/**
+ * Interface for creating notifications in the app
+ */
+interface Notifier {
+    fun onNewsAdded(newsResources: List<NewsResource>)
+}

core/notifications/src/main/res/values/strings.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright 2022 The Android Open Source Project
+
+     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.
+-->
+<resources>
+    <string name="sync_notification_title">Now in Android</string>
+    <string name="sync_notification_channel_name">Sync</string>
+    <string name="sync_notification_channel_description">Background tasks for Now in Android</string>
+
+</resources>

core/notifications/src/prod/java/com/google/samples/apps/nowinandroid/core/notifications/NotificationsModule.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * 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 com.google.samples.apps.nowinandroid.core.notifications
+
+import dagger.Binds
+import dagger.Module
+import dagger.hilt.InstallIn
+import dagger.hilt.components.SingletonComponent
+
+@Module
+@InstallIn(SingletonComponent::class)
+abstract class NotificationsModule {
+    @Binds
+    abstract fun bindNotifier(
+        notifier: AndroidSystemNotifier,
+    ): Notifier
+}

core/testing/build.gradle.kts

@@ -40,5 +40,6 @@ dependencies {
     implementation(project(":core:data"))
     implementation(project(":core:domain"))
     implementation(project(":core:model"))
+    implementation(project(":core:notifications"))
     implementation(libs.kotlinx.datetime)
 }

core/testing/src/main/java/com/google/samples/apps/nowinandroid/core/testing/notifications/TestNotifier.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * 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 com.google.samples.apps.nowinandroid.core.testing.notifications
+
+import com.google.samples.apps.nowinandroid.core.model.data.NewsResource
+import com.google.samples.apps.nowinandroid.core.notifications.Notifier
+
+/**
+ * Aggregates news resources that have been notified for addition
+ */
+class TestNotifier : Notifier {
+
+    private val mutableAddedNewResources = mutableListOf<List<NewsResource>>()
+
+    val addedNewsResources: List<List<NewsResource>> = mutableAddedNewResources
+
+    override fun onNewsAdded(newsResources: List<NewsResource>) {
+        mutableAddedNewResources.add(newsResources)
+    }
+}

core/testing/src/main/java/com/google/samples/apps/nowinandroid/core/testing/util/TestSyncManager.kt

@@ -16,16 +16,20 @@
 
 package com.google.samples.apps.nowinandroid.core.testing.util
 
-import com.google.samples.apps.nowinandroid.core.data.util.SyncStatusMonitor
+import com.google.samples.apps.nowinandroid.core.data.util.SyncManager
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
 
-class TestSyncStatusMonitor : SyncStatusMonitor {
+class TestSyncManager : SyncManager {
 
     private val syncStatusFlow = MutableStateFlow(false)
 
     override val isSyncing: Flow<Boolean> = syncStatusFlow
 
+    override fun requestSync() {
+        TODO("Not yet implemented")
+    }
+
     /**
      * A test-only API to set the sync status from tests.
      */

feature/foryou/src/main/java/com/google/samples/apps/nowinandroid/feature/foryou/ForYouViewModel.kt

@@ -20,7 +20,7 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.google.samples.apps.nowinandroid.core.data.repository.NewsResourceQuery
 import com.google.samples.apps.nowinandroid.core.data.repository.UserDataRepository
-import com.google.samples.apps.nowinandroid.core.data.util.SyncStatusMonitor
+import com.google.samples.apps.nowinandroid.core.data.util.SyncManager
 import com.google.samples.apps.nowinandroid.core.domain.GetFollowableTopicsUseCase
 import com.google.samples.apps.nowinandroid.core.domain.GetUserNewsResourcesUseCase
 import com.google.samples.apps.nowinandroid.core.domain.model.UserNewsResource
@@ -41,7 +41,7 @@ import javax.inject.Inject
 
 @HiltViewModel
 class ForYouViewModel @Inject constructor(
-    syncStatusMonitor: SyncStatusMonitor,
+    syncManager: SyncManager,
     private val userDataRepository: UserDataRepository,
     getUserNewsResources: GetUserNewsResourcesUseCase,
     getFollowableTopics: GetFollowableTopicsUseCase,
@@ -50,7 +50,7 @@ class ForYouViewModel @Inject constructor(
     private val shouldShowOnboarding: Flow<Boolean> =
         userDataRepository.userData.map { !it.shouldHideOnboarding }
 
-    val isSyncing = syncStatusMonitor.isSyncing
+    val isSyncing = syncManager.isSyncing
         .stateIn(
             scope = viewModelScope,
             started = SharingStarted.WhileSubscribed(5_000),

feature/foryou/src/test/java/com/google/samples/apps/nowinandroid/feature/foryou/ForYouViewModelTest.kt

@@ -30,7 +30,7 @@ import com.google.samples.apps.nowinandroid.core.testing.repository.TestUserData
 import com.google.samples.apps.nowinandroid.core.testing.repository.emptyUserData
 import com.google.samples.apps.nowinandroid.core.testing.util.MainDispatcherRule
 import com.google.samples.apps.nowinandroid.core.testing.util.TestNetworkMonitor
-import com.google.samples.apps.nowinandroid.core.testing.util.TestSyncStatusMonitor
+import com.google.samples.apps.nowinandroid.core.testing.util.TestSyncManager
 import com.google.samples.apps.nowinandroid.core.ui.NewsFeedUiState
 import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.launch
@@ -52,7 +52,7 @@ class ForYouViewModelTest {
     val mainDispatcherRule = MainDispatcherRule()
 
     private val networkMonitor = TestNetworkMonitor()
-    private val syncStatusMonitor = TestSyncStatusMonitor()
+    private val syncManager = TestSyncManager()
     private val userDataRepository = TestUserDataRepository()
     private val topicsRepository = TestTopicsRepository()
     private val newsRepository = TestNewsRepository()
@@ -70,7 +70,7 @@ class ForYouViewModelTest {
     @Before
     fun setup() {
         viewModel = ForYouViewModel(
-            syncStatusMonitor = syncStatusMonitor,
+            syncManager = syncManager,
             userDataRepository = userDataRepository,
             getUserNewsResources = getUserNewsResourcesUseCase,
             getFollowableTopics = getFollowableTopicsUseCase,
@@ -106,7 +106,7 @@ class ForYouViewModelTest {
 
     @Test
     fun stateIsLoadingWhenAppIsSyncingWithNoInterests() = runTest {
-        syncStatusMonitor.setSyncing(true)
+        syncManager.setSyncing(true)
 
         val collectJob =
             launch(UnconfinedTestDispatcher()) { viewModel.isSyncing.collect() }

gradle/libs.versions.toml

@@ -103,6 +103,7 @@ coil-kt-compose = { group = "io.coil-kt", name = "coil-compose", version.ref = "
 coil-kt-svg = { group = "io.coil-kt", name = "coil-svg", version.ref = "coil" }
 firebase-bom = { group = "com.google.firebase", name = "firebase-bom", version.ref = "firebaseBom" }
 firebase-analytics = { group = "com.google.firebase", name = "firebase-analytics-ktx" }
+firebase-cloud-messaging = { group = "com.google.firebase", name = "firebase-messaging-ktx" }
 firebase-crashlytics = { group = "com.google.firebase", name = "firebase-crashlytics-ktx" }
 firebase-crashlytics-gradle = { group = "com.google.firebase", name = "firebase-crashlytics-gradle", version.ref = "firebaseCrashlyticsPlugin" }
 firebase-performance = { group = "com.google.firebase", name = "firebase-perf-ktx" }

settings.gradle.kts

@@ -47,6 +47,7 @@ include(":core:network")
 include(":core:ui")
 include(":core:testing")
 include(":core:analytics")
+include(":core:notifications")
 
 include(":feature:foryou")
 include(":feature:interests")

sync/sync-test/src/main/java/com/google/samples/apps/nowinandroid/core/sync/test/NeverSyncingSyncManager.kt

@@ -16,11 +16,12 @@
 
 package com.google.samples.apps.nowinandroid.core.sync.test
 
-import com.google.samples.apps.nowinandroid.core.data.util.SyncStatusMonitor
+import com.google.samples.apps.nowinandroid.core.data.util.SyncManager
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flowOf
 import javax.inject.Inject
 
-class NeverSyncingSyncStatusMonitor @Inject constructor() : SyncStatusMonitor {
+class NeverSyncingSyncManager @Inject constructor() : SyncManager {
     override val isSyncing: Flow<Boolean> = flowOf(false)
+    override fun requestSync() = Unit
 }

sync/sync-test/src/main/java/com/google/samples/apps/nowinandroid/core/sync/test/TestSyncModule.kt

@@ -16,7 +16,7 @@
 
 package com.google.samples.apps.nowinandroid.core.sync.test
 
-import com.google.samples.apps.nowinandroid.core.data.util.SyncStatusMonitor
+import com.google.samples.apps.nowinandroid.core.data.util.SyncManager
 import com.google.samples.apps.nowinandroid.sync.di.SyncModule
 import dagger.Binds
 import dagger.Module
@@ -31,6 +31,6 @@ import dagger.hilt.testing.TestInstallIn
 interface TestSyncModule {
     @Binds
     fun bindsSyncStatusMonitor(
-        syncStatusMonitor: NeverSyncingSyncStatusMonitor,
-    ): SyncStatusMonitor
+        syncStatusMonitor: NeverSyncingSyncManager,
+    ): SyncManager
 }

sync/work/build.gradle.kts

@@ -36,6 +36,7 @@ dependencies {
     implementation(libs.androidx.startup)
     implementation(libs.androidx.tracing.ktx)
     implementation(libs.androidx.work.ktx)
+    implementation(libs.firebase.cloud.messaging)
     implementation(libs.hilt.ext.work)
     implementation(libs.kotlinx.coroutines.android)
 

sync/work/src/demo/AndroidManifest.xml

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright 2022 The Android Open Source Project
+
+     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.
+-->
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools">
+
+    <application>
+        <provider
+            android:name="androidx.startup.InitializationProvider"
+            android:authorities="${applicationId}.androidx-startup"
+            android:exported="false"
+            tools:node="merge">
+            <!--  TODO: b/2173216 Disable auto sync startup till it works well with instrumented tests   -->
+            <meta-data
+                android:name="com.google.samples.apps.nowinandroid.sync.initializers.SyncInitializer"
+                android:value="androidx.startup"
+                tools:node="remove" />
+        </provider>
+        <service
+            android:name=".services.SyncNotificationsService"
+            android:exported="false"
+            tools:node="remove" />
+    </application>
+
+</manifest>

sync/work/src/main/AndroidManifest.xml

@@ -29,7 +29,13 @@
                 android:value="androidx.startup"
                 tools:node="remove" />
         </provider>
-
+        <service
+            android:name=".services.SyncNotificationsService"
+            android:exported="false">
+            <intent-filter>
+                <action android:name="com.google.firebase.MESSAGING_EVENT" />
+            </intent-filter>
+        </service>
     </application>
 
 </manifest>

sync/work/src/main/java/com/google/samples/apps/nowinandroid/sync/di/SyncModule.kt

@@ -16,8 +16,8 @@
 
 package com.google.samples.apps.nowinandroid.sync.di
 
-import com.google.samples.apps.nowinandroid.core.data.util.SyncStatusMonitor
-import com.google.samples.apps.nowinandroid.sync.status.WorkManagerSyncStatusMonitor
+import com.google.samples.apps.nowinandroid.core.data.util.SyncManager
+import com.google.samples.apps.nowinandroid.sync.status.WorkManagerSyncManager
 import dagger.Binds
 import dagger.Module
 import dagger.hilt.InstallIn
@@ -28,6 +28,6 @@ import dagger.hilt.components.SingletonComponent
 interface SyncModule {
     @Binds
     fun bindsSyncStatusMonitor(
-        syncStatusMonitor: WorkManagerSyncStatusMonitor,
-    ): SyncStatusMonitor
+        syncStatusMonitor: WorkManagerSyncManager,
+    ): SyncManager
 }

sync/work/src/main/java/com/google/samples/apps/nowinandroid/sync/services/SyncNotificationsService.kt

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * 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 com.google.samples.apps.nowinandroid.sync.services
+
+import com.google.firebase.messaging.FirebaseMessagingService
+import com.google.firebase.messaging.RemoteMessage
+import com.google.samples.apps.nowinandroid.core.data.util.SyncManager
+import dagger.hilt.android.AndroidEntryPoint
+import javax.inject.Inject
+
+private const val SYNC_TOPIC = "sync"
+
+@AndroidEntryPoint
+class SyncNotificationsService : FirebaseMessagingService() {
+
+    @Inject
+    lateinit var syncManager: SyncManager
+
+    override fun onMessageReceived(message: RemoteMessage) {
+        if (SYNC_TOPIC == message.from) {
+            syncManager.requestSync()
+        }
+    }
+}

sync/work/src/main/java/com/google/samples/apps/nowinandroid/sync/status/WorkManagerSyncManager.kt

@@ -19,27 +19,39 @@ package com.google.samples.apps.nowinandroid.sync.status
 import android.content.Context
 import androidx.lifecycle.asFlow
 import androidx.lifecycle.map
+import androidx.work.ExistingWorkPolicy
 import androidx.work.WorkInfo
 import androidx.work.WorkInfo.State
 import androidx.work.WorkManager
-import com.google.samples.apps.nowinandroid.core.data.util.SyncStatusMonitor
+import com.google.samples.apps.nowinandroid.core.data.util.SyncManager
 import com.google.samples.apps.nowinandroid.sync.initializers.SyncWorkName
+import com.google.samples.apps.nowinandroid.sync.workers.SyncWorker
 import dagger.hilt.android.qualifiers.ApplicationContext
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.conflate
 import javax.inject.Inject
 
 /**
- * [SyncStatusMonitor] backed by [WorkInfo] from [WorkManager]
+ * [SyncManager] backed by [WorkInfo] from [WorkManager]
  */
-class WorkManagerSyncStatusMonitor @Inject constructor(
-    @ApplicationContext context: Context,
-) : SyncStatusMonitor {
+class WorkManagerSyncManager @Inject constructor(
+    @ApplicationContext private val context: Context,
+) : SyncManager {
     override val isSyncing: Flow<Boolean> =
         WorkManager.getInstance(context).getWorkInfosForUniqueWorkLiveData(SyncWorkName)
             .map(MutableList<WorkInfo>::anyRunning)
             .asFlow()
             .conflate()
+
+    override fun requestSync() {
+        val workManager = WorkManager.getInstance(context)
+        // Run sync on app startup and ensure only one sync worker runs at any time
+        workManager.enqueueUniqueWork(
+            SyncWorkName,
+            ExistingWorkPolicy.KEEP,
+            SyncWorker.startUpSyncWork(),
+        )
+    }
 }
 
 private val List<WorkInfo>.anyRunning get() = any { it.state == State.RUNNING }