Make survey list reactive to local and remote changes

ground/build.gradle

@@ -193,9 +193,9 @@ dependencies {
     testImplementation 'org.json:json:20180813'
 
     // Firebase and related libraries.
-    implementation platform('com.google.firebase:firebase-bom:32.2.3')
+    implementation platform('com.google.firebase:firebase-bom:32.4.1')
     implementation 'com.google.firebase:firebase-analytics'
-    implementation 'com.google.firebase:firebase-firestore-ktx'
+    implementation 'com.google.firebase:firebase-firestore'
     implementation 'com.google.firebase:firebase-functions-ktx'
     implementation 'com.google.firebase:firebase-auth'
     implementation 'com.google.firebase:firebase-perf'

ground/src/main/java/com/google/android/ground/ui/surveyselector/SurveyItem.kt → ground/src/main/java/com/google/android/ground/model/SurveyListItem.kt

@@ -14,11 +14,14 @@
  * limitations under the License.
  */
 
-package com.google.android.ground.ui.surveyselector
+package com.google.android.ground.model
 
-data class SurveyItem(
-  val surveyId: String,
-  val surveyTitle: String,
-  val surveyDescription: String,
-  val isAvailableOffline: Boolean
+data class SurveyListItem(
+  val id: String,
+  val title: String,
+  val description: String,
+  val availableOffline: Boolean
 )
+
+fun Survey.toListItem(availableOffline: Boolean): SurveyListItem =
+  SurveyListItem(id, title, description, availableOffline)

ground/src/main/java/com/google/android/ground/persistence/remote/RemoteDataStore.kt

@@ -16,18 +16,20 @@
 package com.google.android.ground.persistence.remote
 
 import com.google.android.ground.model.Survey
+import com.google.android.ground.model.SurveyListItem
 import com.google.android.ground.model.TermsOfService
 import com.google.android.ground.model.User
 import com.google.android.ground.model.locationofinterest.LocationOfInterest
 import com.google.android.ground.model.mutation.Mutation
 import com.google.android.ground.model.submission.Submission
+import kotlinx.coroutines.flow.Flow
 
 /**
  * Defines API for accessing data in a remote data store. Implementations must ensure all
  * subscriptions are run in a background thread (i.e., not the Android main thread).
  */
 interface RemoteDataStore {
-  suspend fun loadSurveySummaries(user: User): List<Survey>
+  fun getSurveyList(user: User): Flow<List<SurveyListItem>>
 
   /**
    * Loads the survey with the specified id from the remote data store. Returns `null` if the survey

ground/src/main/java/com/google/android/ground/persistence/remote/firebase/FirestoreDataStore.kt

@@ -17,13 +17,15 @@ package com.google.android.ground.persistence.remote.firebase
 
 import com.google.android.ground.coroutines.IoDispatcher
 import com.google.android.ground.model.Survey
+import com.google.android.ground.model.SurveyListItem
 import com.google.android.ground.model.TermsOfService
 import com.google.android.ground.model.User
 import com.google.android.ground.model.locationofinterest.LocationOfInterest
 import com.google.android.ground.model.mutation.LocationOfInterestMutation
 import com.google.android.ground.model.mutation.Mutation
 import com.google.android.ground.model.mutation.SubmissionMutation
 import com.google.android.ground.model.submission.Submission
+import com.google.android.ground.model.toListItem
 import com.google.android.ground.persistence.remote.RemoteDataStore
 import com.google.firebase.firestore.WriteBatch
 import com.google.firebase.functions.FirebaseFunctions
@@ -32,6 +34,10 @@ import com.google.firebase.messaging.ktx.messaging
 import javax.inject.Inject
 import javax.inject.Singleton
 import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.emitAll
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.tasks.await
 import kotlinx.coroutines.withContext
 import timber.log.Timber
@@ -64,8 +70,14 @@ internal constructor(
   override suspend fun loadTermsOfService(): TermsOfService? =
     withContext(ioDispatcher) { db().termsOfService().terms().get() }
 
-  override suspend fun loadSurveySummaries(user: User): List<Survey> =
-    withContext(ioDispatcher) { db().surveys().getReadable(user) }
+  override fun getSurveyList(user: User): Flow<List<SurveyListItem>> = flow {
+    emitAll(
+      db().surveys().getReadable(user).map { list ->
+        // TODO(#2031): Return SurveyListItem from getReadable(), only fetch required fields.
+        list.map { it.toListItem(false) }
+      }
+    )
+  }
 
   override suspend fun loadLocationsOfInterest(survey: Survey) =
     db().surveys().survey(survey.id).lois().locationsOfInterest(survey)

ground/src/main/java/com/google/android/ground/persistence/remote/firebase/schema/SurveysCollectionReference.kt

@@ -21,8 +21,10 @@ import com.google.android.ground.model.Survey
 import com.google.android.ground.model.User
 import com.google.android.ground.persistence.remote.firebase.base.FluentCollectionReference
 import com.google.firebase.firestore.CollectionReference
-import com.google.firebase.firestore.DocumentSnapshot
 import com.google.firebase.firestore.FieldPath
+import com.google.firebase.firestore.snapshots
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
 
 private const val ACL_FIELD = "acl"
 
@@ -31,9 +33,8 @@ class SurveysCollectionReference internal constructor(ref: CollectionReference)
 
   fun survey(id: String) = SurveyDocumentReference(reference().document(id))
 
-  suspend fun getReadable(user: User): List<Survey> =
-    runQuery(reference().whereIn(FieldPath.of(ACL_FIELD, user.email), Role.valueStrings())) {
-      doc: DocumentSnapshot ->
-      SurveyConverter.toSurvey(doc)
+  fun getReadable(user: User): Flow<List<Survey>> =
+    reference().whereIn(FieldPath.of(ACL_FIELD, user.email), Role.valueStrings()).snapshots().map {
+      it.documents.map { doc -> SurveyConverter.toSurvey(doc) }
     }
 }

ground/src/main/java/com/google/android/ground/repository/SurveyRepository.kt

@@ -17,30 +17,34 @@ package com.google.android.ground.repository
 
 import com.google.android.ground.coroutines.ApplicationScope
 import com.google.android.ground.model.Survey
+import com.google.android.ground.model.SurveyListItem
 import com.google.android.ground.model.User
+import com.google.android.ground.model.toListItem
 import com.google.android.ground.persistence.local.LocalValueStore
 import com.google.android.ground.persistence.local.stores.LocalSurveyStore
 import com.google.android.ground.persistence.remote.RemoteDataStore
 import com.google.android.ground.rx.annotations.Cold
+import com.google.android.ground.system.NetworkManager
+import com.google.android.ground.system.NetworkStatus
 import io.reactivex.Flowable
 import java8.util.Optional
 import javax.inject.Inject
 import javax.inject.Singleton
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharedFlow
 import kotlinx.coroutines.flow.SharingStarted
-import kotlinx.coroutines.flow.asFlow
+import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.shareIn
 import kotlinx.coroutines.rx2.asFlowable
-import kotlinx.coroutines.withTimeout
 import kotlinx.coroutines.withTimeoutOrNull
 import timber.log.Timber
 
 private const val LOAD_REMOTE_SURVEY_TIMEOUT_MILLS: Long = 15 * 1000
-private const val LOAD_REMOTE_SURVEY_SUMMARIES_TIMEOUT_MILLIS: Long = 30 * 1000
 
 /**
  * Coordinates persistence and retrieval of [Survey] instances from remote, local, and in memory
@@ -54,6 +58,7 @@ constructor(
   private val localSurveyStore: LocalSurveyStore,
   private val remoteDataStore: RemoteDataStore,
   private val localValueStore: LocalValueStore,
+  private val networkManager: NetworkManager,
   @ApplicationScope private val externalScope: CoroutineScope
 ) {
   private val _activeSurvey = MutableStateFlow<Survey?>(null)
@@ -82,8 +87,8 @@ constructor(
   val activeSurveyFlowable: @Cold Flowable<Optional<Survey>> =
     activeSurveyFlow.map { if (it == null) Optional.empty() else Optional.of(it) }.asFlowable()
 
-  val offlineSurveys: Flow<List<Survey>>
-    get() = localSurveyStore.surveys
+  val localSurveyListFlow: Flow<List<SurveyListItem>>
+    get() = localSurveyStore.surveys.map { list -> list.map { it.toListItem(true) } }
 
   var lastActiveSurveyId: String by localValueStore::lastActiveSurveyId
     internal set
@@ -115,17 +120,22 @@ constructor(
     activeSurvey = null
   }
 
-  suspend fun getSurveySummaries(user: User): Flow<List<Survey>> =
-    try {
-      val surveys =
-        withTimeout(LOAD_REMOTE_SURVEY_SUMMARIES_TIMEOUT_MILLIS) {
-          Timber.d("Loading survey list from remote")
-          remoteDataStore.loadSurveySummaries(user)
-        }
-      listOf(surveys).asFlow()
-    } catch (e: Throwable) {
-      Timber.d(e, "Failed to load survey list from remote")
-      offlineSurveys
+  fun getSurveyList(user: User): Flow<List<SurveyListItem>> =
+    @OptIn(ExperimentalCoroutinesApi::class)
+    networkManager.networkStatusFlow.flatMapLatest { networkStatus ->
+      if (networkStatus == NetworkStatus.AVAILABLE) {
+        getRemoteSurveyList(user)
+      } else {
+        localSurveyListFlow
+      }
+    }
+
+  private fun getRemoteSurveyList(user: User): Flow<List<SurveyListItem>> =
+    remoteDataStore.getSurveyList(user).combine(localSurveyListFlow) { remoteSurveys, localSurveys
+      ->
+      remoteSurveys.map { remoteSurvey ->
+        remoteSurvey.copy(availableOffline = localSurveys.any { it.id == remoteSurvey.id })
+      }
     }
 
   /** Attempts to remove the locally synced survey. Doesn't throw an error if it doesn't exist. */

ground/src/main/java/com/google/android/ground/system/NetworkManager.kt

@@ -17,15 +17,49 @@ package com.google.android.ground.system
 
 import android.content.Context
 import android.net.ConnectivityManager
+import android.net.Network
+import android.net.NetworkCapabilities.NET_CAPABILITY_INTERNET
+import android.net.NetworkRequest
 import androidx.annotation.RequiresPermission
 import dagger.hilt.android.qualifiers.ApplicationContext
 import java.net.ConnectException
 import javax.inject.Inject
 import javax.inject.Singleton
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.callbackFlow
 
+enum class NetworkStatus {
+  AVAILABLE,
+  UNAVAILABLE
+}
 /** Abstracts access to network state. */
 @Singleton
 class NetworkManager @Inject constructor(@ApplicationContext private val context: Context) {
+  val networkStatusFlow = initNetworkStatusFlow()
+
+  fun initNetworkStatusFlow(): Flow<NetworkStatus> {
+    val connectivityManager = context.getSystemService(ConnectivityManager::class.java)
+    return callbackFlow {
+      val callback =
+        object : ConnectivityManager.NetworkCallback() {
+          override fun onAvailable(network: Network) {
+            trySend(NetworkStatus.AVAILABLE)
+          }
+
+          override fun onLost(network: Network) {
+            trySend(NetworkStatus.UNAVAILABLE)
+          }
+        }
+
+      val request = NetworkRequest.Builder().addCapability(NET_CAPABILITY_INTERNET).build()
+      // Emit initial state.
+      trySend(if (isNetworkConnected()) NetworkStatus.AVAILABLE else NetworkStatus.UNAVAILABLE)
+      connectivityManager.registerNetworkCallback(request, callback)
+
+      awaitClose { connectivityManager.unregisterNetworkCallback(callback) }
+    }
+  }
 
   /** Returns true iff the device has internet connectivity, false otherwise. */
   @RequiresPermission("android.permission.ACCESS_NETWORK_STATE")

ground/src/main/java/com/google/android/ground/ui/surveyselector/SurveyListAdapter.kt

@@ -20,28 +20,29 @@ import android.view.LayoutInflater
 import android.view.ViewGroup
 import androidx.recyclerview.widget.RecyclerView
 import com.google.android.ground.databinding.SurveyCardItemBinding
+import com.google.android.ground.model.SurveyListItem
 import com.google.android.ground.ui.surveyselector.SurveyListAdapter.ViewHolder
 
 /**
- * An implementation of [RecyclerView.Adapter] that associates [SurveyItem] data with the
+ * An implementation of [RecyclerView.Adapter] that associates [SurveyListItem] data with the
  * [ViewHolder] views.
  */
 class SurveyListAdapter(
   private val viewModel: SurveySelectorViewModel,
   private val fragment: SurveySelectorFragment
 ) : RecyclerView.Adapter<ViewHolder>() {
 
-  private val surveys: MutableList<SurveyItem> = mutableListOf()
+  private val surveys: MutableList<SurveyListItem> = mutableListOf()
 
   /** Creates a new [ViewHolder] item without any data. */
   override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
     val binding = SurveyCardItemBinding.inflate(LayoutInflater.from(parent.context), parent, false)
     return ViewHolder(binding)
   }
 
-  /** Binds [SurveyItem] data to [ViewHolder]. */
+  /** Binds [SurveyListItem] data to [ViewHolder]. */
   override fun onBindViewHolder(holder: ViewHolder, position: Int) {
-    val item: SurveyItem = surveys[position]
+    val item: SurveyListItem = surveys[position]
     holder.binding.item = item
     holder.binding.viewModel = viewModel
     holder.binding.fragment = fragment
@@ -51,13 +52,13 @@ class SurveyListAdapter(
   override fun getItemCount() = surveys.size
 
   /** Overwrites existing cards. */
-  fun updateData(newItemsList: List<SurveyItem>) {
+  fun updateData(newItemsList: List<SurveyListItem>) {
     surveys.clear()
     surveys.addAll(newItemsList)
     notifyDataSetChanged()
   }
 
-  /** View item representing the [SurveyItem] data in the list. */
+  /** View item representing the [SurveyListItem] data in the list. */
   class ViewHolder(internal val binding: SurveyCardItemBinding) :
     RecyclerView.ViewHolder(binding.root)
 }

ground/src/main/java/com/google/android/ground/ui/surveyselector/SurveySelectorViewModel.kt

@@ -19,7 +19,7 @@ import androidx.lifecycle.viewModelScope
 import com.google.android.ground.coroutines.ApplicationScope
 import com.google.android.ground.coroutines.IoDispatcher
 import com.google.android.ground.domain.usecases.survey.ActivateSurveyUseCase
-import com.google.android.ground.model.Survey
+import com.google.android.ground.model.SurveyListItem
 import com.google.android.ground.repository.SurveyRepository
 import com.google.android.ground.repository.UserRepository
 import com.google.android.ground.system.auth.AuthenticationManager
@@ -29,16 +29,14 @@ import com.google.android.ground.ui.home.HomeScreenFragmentDirections
 import javax.inject.Inject
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.FlowPreview
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.flatMapMerge
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.flow.onStart
 import kotlinx.coroutines.launch
 
 /** Represents view state and behaviors of the survey selector dialog. */
-@OptIn(FlowPreview::class)
 class SurveySelectorViewModel
 @Inject
 internal constructor(
@@ -52,11 +50,11 @@ internal constructor(
 ) : AbstractViewModel() {
 
   val surveyListState: MutableStateFlow<State?> = MutableStateFlow(null)
-  val surveySummaries: Flow<List<SurveyItem>>
+  val surveySummaries: Flow<List<SurveyListItem>>
 
   init {
     surveySummaries =
-      createSurveySummaries().onEach {
+      getSurveyList().onEach {
         if (it.isEmpty()) {
           setNotFound()
         } else {
@@ -65,32 +63,12 @@ internal constructor(
       }
   }
 
-  /** Returns a flow of locally stored surveys. */
-  private fun offlineSurveys(): Flow<List<Survey>> =
-    surveyRepository.offlineSurveys.onEach { setLoading() }
-
-  /** Returns a flow of remotely stored surveys. */
-  private suspend fun allSurveys(): Flow<List<Survey>> =
-    surveyRepository.getSurveySummaries(authManager.currentUser).onEach { setLoading() }
-
-  /** Returns a flow of [SurveyItem] to be displayed to the user. */
-  private fun createSurveySummaries(): Flow<List<SurveyItem>> =
-    offlineSurveys().flatMapMerge { offlineSurveys: List<Survey> ->
-      allSurveys().map { allSurveys: List<Survey> ->
-        allSurveys
-          .map { createSurveyItem(it, offlineSurveys) }
-          .sortedBy { it.surveyTitle }
-          .sortedByDescending { it.isAvailableOffline }
-      }
-    }
-
-  private fun createSurveyItem(survey: Survey, localSurveys: List<Survey>): SurveyItem =
-    SurveyItem(
-      surveyId = survey.id,
-      surveyTitle = survey.title,
-      surveyDescription = survey.description,
-      isAvailableOffline = localSurveys.any { it.id == survey.id }
-    )
+  /** Returns a flow of [SurveyListItem] to be displayed to the user. */
+  private fun getSurveyList(): Flow<List<SurveyListItem>> =
+    surveyRepository
+      .getSurveyList(authManager.currentUser)
+      .onStart { setLoading() }
+      .map { surveys -> surveys.sortedBy { it.title }.sortedByDescending { it.availableOffline } }
 
   /** Triggers the specified survey to be loaded and activated. */
   fun activateSurvey(surveyId: String) =