Add SearchResultNotReadyBody

That is displayed when *Fts tables are not populated

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

@@ -74,4 +74,13 @@ class DefaultSearchContentsRepository @Inject constructor(
             )
         }
     }
+
+    override fun getSearchContentsCount(): Flow<Int> {
+        return combine(
+            newsResourceFtsDao.getCount(),
+            topicFtsDao.getCount(),
+        ) { newsResourceCount, topicsCount ->
+            newsResourceCount + topicsCount
+        }
+    }
 }

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

@@ -33,4 +33,6 @@ interface SearchContentsRepository {
      * Query the contents matched with the [searchQuery] and returns it as a [Flow] of [SearchResult]
      */
     fun searchContents(searchQuery: String): Flow<SearchResult>
+
+    fun getSearchContentsCount(): Flow<Int>
 }

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

@@ -29,4 +29,5 @@ class FakeSearchContentsRepository @Inject constructor() : SearchContentsReposit
 
     override suspend fun populateFtsData() { /* no-op */ }
     override fun searchContents(searchQuery: String): Flow<SearchResult> = flowOf()
+    override fun getSearchContentsCount(): Flow<Int> = flowOf(1)
 }

core/database/src/main/java/com/google/samples/apps/nowinandroid/core/database/dao/NewsResourceFtsDao.kt

@@ -35,5 +35,5 @@ interface NewsResourceFtsDao {
     fun searchAllNewsResources(query: String): Flow<List<String>>
 
     @Query("SELECT count(*) FROM newsResourcesFts")
-    suspend fun getCount(): Int
+    fun getCount(): Flow<Int>
 }

core/database/src/main/java/com/google/samples/apps/nowinandroid/core/database/dao/TopicFtsDao.kt

@@ -35,5 +35,5 @@ interface TopicFtsDao {
     fun searchAllTopics(query: String): Flow<List<String>>
 
     @Query("SELECT count(*) FROM topicsFts")
-    suspend fun getCount(): Int
+    fun getCount(): Flow<Int>
 }

core/domain/src/main/java/com/google/samples/apps/nowinandroid/core/domain/GetSearchContentsCountUseCase.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.domain
+
+import com.google.samples.apps.nowinandroid.core.data.repository.SearchContentsRepository
+import kotlinx.coroutines.flow.Flow
+import javax.inject.Inject
+
+/**
+ * A use case which returns total count of *Fts tables
+ */
+class GetSearchContentsCountUseCase @Inject constructor(
+    private val searchContentsRepository: SearchContentsRepository,
+) {
+    operator fun invoke(): Flow<Int> =
+        searchContentsRepository.getSearchContentsCount()
+}

core/testing/src/main/java/com/google/samples/apps/nowinandroid/core/testing/repository/TestSearchContentsRepository.kt

@@ -21,6 +21,7 @@ import com.google.samples.apps.nowinandroid.core.data.repository.SearchContentsR
 import com.google.samples.apps.nowinandroid.core.model.data.NewsResource
 import com.google.samples.apps.nowinandroid.core.model.data.Topic
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.flowOf
 
 class TestSearchContentsRepository : SearchContentsRepository {
@@ -44,6 +45,10 @@ class TestSearchContentsRepository : SearchContentsRepository {
         ),
     )
 
+    override fun getSearchContentsCount(): Flow<Int> = flow {
+        emit(cachedTopics.size + cachedNewsResources.size)
+    }
+
     /**
      * Test only method to add the topics to the stored list in memory
      */

feature/search/src/androidTest/java/com/google/samples/apps/nowinandroid/feature/search/SearchScreenTest.kt

@@ -52,6 +52,7 @@ class SearchScreenTest {
     private lateinit var topicsString: String
     private lateinit var updatesString: String
     private lateinit var tryAnotherSearchString: String
+    private lateinit var searchNotReadyString: String
 
     private val userData: UserData = UserData(
         bookmarkedNewsResources = setOf("1", "3"),
@@ -75,6 +76,7 @@ class SearchScreenTest {
             updatesString = getString(R.string.updates)
             tryAnotherSearchString = getString(R.string.try_another_search) +
                 " " + getString(R.string.interests) + " " + getString(R.string.to_browse_topics)
+            searchNotReadyString = getString(R.string.search_not_ready)
         }
     }
 
@@ -199,4 +201,17 @@ class SearchScreenTest {
             .onNodeWithText("testing")
             .assertIsDisplayed()
     }
+
+    @Test
+    fun searchNotReady_verifySearchNotReadyMessageIsVisible() {
+        composeTestRule.setContent {
+            SearchScreen(
+                searchResultUiState = SearchResultUiState.SearchNotReady,
+            )
+        }
+
+        composeTestRule
+            .onNodeWithText(searchNotReadyString)
+            .assertIsDisplayed()
+    }
 }

feature/search/src/main/java/com/google/samples/apps/nowinandroid/feature/search/SearchResultUiState.kt

@@ -37,4 +37,10 @@ sealed interface SearchResultUiState {
     ) : SearchResultUiState {
         fun isEmpty(): Boolean = topics.isEmpty() && newsResources.isEmpty()
     }
+
+    /**
+     * A state where the search contents are not ready. This happens when the *Fts tables are not
+     * populated yet.
+     */
+    object SearchNotReady : SearchResultUiState
 }

feature/search/src/main/java/com/google/samples/apps/nowinandroid/feature/search/SearchScreen.kt

@@ -150,6 +150,7 @@ internal fun SearchScreen(
             SearchResultUiState.LoadFailed,
             -> Unit
 
+            SearchResultUiState.SearchNotReady -> SearchNotReadyBody()
             SearchResultUiState.EmptyQuery,
             -> {
                 if (recentSearchesUiState is RecentSearchQueriesUiState.Success) {
@@ -260,6 +261,21 @@ fun EmptySearchResultBody(
     }
 }
 
+@Composable
+private fun SearchNotReadyBody() {
+    Column(
+        horizontalAlignment = Alignment.CenterHorizontally,
+        modifier = Modifier.padding(horizontal = 48.dp),
+    ) {
+        Text(
+            text = stringResource(id = searchR.string.search_not_ready),
+            fontSize = 18.sp,
+            textAlign = TextAlign.Center,
+            modifier = Modifier.padding(vertical = 24.dp),
+        )
+    }
+}
+
 @Composable
 private fun SearchResultBody(
     topics: List<FollowableTopic>,
@@ -526,6 +542,14 @@ private fun RecentSearchesBodyPreview() {
     }
 }
 
+@Preview
+@Composable
+private fun SearchNotReadyBodyPreview() {
+    NiaTheme {
+        SearchNotReadyBody()
+    }
+}
+
 @DevicePreviews
 @Composable
 private fun SearchScreenPreview(

feature/search/src/main/java/com/google/samples/apps/nowinandroid/feature/search/SearchViewModel.kt

@@ -21,6 +21,7 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.google.samples.apps.nowinandroid.core.data.repository.RecentSearchRepository
 import com.google.samples.apps.nowinandroid.core.domain.GetRecentSearchQueriesUseCase
+import com.google.samples.apps.nowinandroid.core.domain.GetSearchContentsCountUseCase
 import com.google.samples.apps.nowinandroid.core.domain.GetSearchContentsUseCase
 import com.google.samples.apps.nowinandroid.core.result.Result
 import com.google.samples.apps.nowinandroid.core.result.asResult
@@ -36,8 +37,8 @@ import javax.inject.Inject
 
 @HiltViewModel
 class SearchViewModel @Inject constructor(
-    // TODO: Add GetSearchContentsCountUseCase to check if the fts tables are populated
     getSearchContentsUseCase: GetSearchContentsUseCase,
+    getSearchContentsCountUseCase: GetSearchContentsCountUseCase,
     recentSearchQueriesUseCase: GetRecentSearchQueriesUseCase,
     private val recentSearchRepository: RecentSearchRepository,
     private val savedStateHandle: SavedStateHandle,
@@ -46,25 +47,31 @@ class SearchViewModel @Inject constructor(
     val searchQuery = savedStateHandle.getStateFlow(SEARCH_QUERY, "")
 
     val searchResultUiState: StateFlow<SearchResultUiState> =
-        searchQuery.flatMapLatest { query ->
-            if (query.length < SEARCH_QUERY_MIN_LENGTH) {
-                flowOf(SearchResultUiState.EmptyQuery)
+        getSearchContentsCountUseCase().flatMapLatest { totalCount ->
+            if (totalCount < SEARCH_MIN_FTS_ENTITY_COUNT) {
+                flowOf(SearchResultUiState.SearchNotReady)
             } else {
-                getSearchContentsUseCase(query).asResult().map {
-                    when (it) {
-                        is Result.Success -> {
-                            SearchResultUiState.Success(
-                                topics = it.data.topics,
-                                newsResources = it.data.newsResources,
-                            )
-                        }
+                searchQuery.flatMapLatest { query ->
+                    if (query.length < SEARCH_QUERY_MIN_LENGTH) {
+                        flowOf(SearchResultUiState.EmptyQuery)
+                    } else {
+                        getSearchContentsUseCase(query).asResult().map {
+                            when (it) {
+                                is Result.Success -> {
+                                    SearchResultUiState.Success(
+                                        topics = it.data.topics,
+                                        newsResources = it.data.newsResources,
+                                    )
+                                }
 
-                        is Result.Loading -> {
-                            SearchResultUiState.Loading
-                        }
+                                is Result.Loading -> {
+                                    SearchResultUiState.Loading
+                                }
 
-                        is Result.Error -> {
-                            SearchResultUiState.LoadFailed
+                                is Result.Error -> {
+                                    SearchResultUiState.LoadFailed
+                                }
+                            }
                         }
                     }
                 }
@@ -109,4 +116,7 @@ class SearchViewModel @Inject constructor(
 
 /** Minimum length where search query is considered as [SearchResultUiState.EmptyQuery] */
 const val SEARCH_QUERY_MIN_LENGTH = 2
+
+/** Minimum number of the fts table's entity count where it's considered as search is not ready */
+const val SEARCH_MIN_FTS_ENTITY_COUNT = 1
 const val SEARCH_QUERY = "searchQuery"

feature/search/src/main/res/values/strings.xml

@@ -18,6 +18,7 @@
     <string name="search">Search</string>
     <string name="clear_search_text_content_desc">Clear search text</string>
     <string name="search_result_not_found">Sorry, there is no content found for your search \"%1$s\"</string>
+    <string name="search_not_ready">Sorry, we are still processing the search index. Please come back later</string>
     <string name="try_another_search">Try another search or explorer </string>
     <string name="interests">Interests</string>
     <string name="to_browse_topics"> to browse topics</string>

feature/search/src/test/java/com/google/samples/apps/nowinandroid/feature/search/SearchViewModelTest.kt

@@ -18,6 +18,7 @@ package com.google.samples.apps.nowinandroid.feature.search
 
 import androidx.lifecycle.SavedStateHandle
 import com.google.samples.apps.nowinandroid.core.domain.GetRecentSearchQueriesUseCase
+import com.google.samples.apps.nowinandroid.core.domain.GetSearchContentsCountUseCase
 import com.google.samples.apps.nowinandroid.core.domain.GetSearchContentsUseCase
 import com.google.samples.apps.nowinandroid.core.testing.data.newsResourcesTestData
 import com.google.samples.apps.nowinandroid.core.testing.data.topicsTestData
@@ -55,12 +56,14 @@ class SearchViewModelTest {
     )
     private val recentSearchRepository = TestRecentSearchRepository()
     private val getRecentQueryUseCase = GetRecentSearchQueriesUseCase(recentSearchRepository)
+    private val getSearchContentsCountUseCase = GetSearchContentsCountUseCase(searchContentsRepository)
     private lateinit var viewModel: SearchViewModel
 
     @Before
     fun setup() {
         viewModel = SearchViewModel(
             getSearchContentsUseCase = getSearchContentsUseCase,
+            getSearchContentsCountUseCase = getSearchContentsCountUseCase,
             recentSearchQueriesUseCase = getRecentQueryUseCase,
             savedStateHandle = SavedStateHandle(),
             recentSearchRepository = recentSearchRepository,