Introduce Network Monitor to Detect Offline Mode

app/src/main/kotlin/com/andreolas/movierama/MainActivity.kt

@@ -9,15 +9,23 @@ import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
 import com.andreolas.movierama.ui.MovieApp
+import com.andreolas.movierama.ui.rememberMovieAppState
+import com.divinelink.core.data.network.NetworkMonitor
 import com.divinelink.core.designsystem.theme.AppTheme
 import com.divinelink.core.designsystem.theme.Theme
 import org.koin.androidx.viewmodel.ext.android.viewModel
+import org.koin.core.component.KoinComponent
+import org.koin.core.component.inject
 
 @ExperimentalAnimationApi
-class MainActivity : ComponentActivity() {
+class MainActivity :
+  ComponentActivity(),
+  KoinComponent {
 
   private val viewModel: MainViewModel by viewModel()
 
+  private val networkMonitor: NetworkMonitor by inject<NetworkMonitor>()
+
   override fun onNewIntent(intent: Intent) {
     super.onNewIntent(intent)
     if (intent.action == Intent.ACTION_VIEW) {
@@ -27,19 +35,23 @@ class MainActivity : ComponentActivity() {
 
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
-
     setContent {
       val darkTheme = shouldUseDarkTheme(
         uiState = viewModel.uiState.collectAsState().value,
         selectedTheme = viewModel.theme.collectAsState().value,
       )
 
+      val appState = rememberMovieAppState(
+        networkMonitor = networkMonitor,
+      )
+
       AppTheme(
         useDarkTheme = darkTheme,
         dynamicColor = viewModel.materialYou.collectAsState().value,
         blackBackground = viewModel.blackBackgrounds.collectAsState().value,
       ) {
         MovieApp(
+          appState = appState,
           uiState = viewModel.uiState.collectAsState().value,
           uiEvent = viewModel.uiEvent.collectAsState().value,
           onConsumeEvent = viewModel::consumeUiEvent,

app/src/main/kotlin/com/andreolas/movierama/home/ui/HomeContent.kt

@@ -30,10 +30,11 @@ import com.divinelink.core.designsystem.theme.AppTheme
 import com.divinelink.core.designsystem.theme.SearchBarShape
 import com.divinelink.core.designsystem.theme.dimensions
 import com.divinelink.core.model.home.HomeMode
+import com.divinelink.core.model.home.HomePage
 import com.divinelink.core.model.media.MediaItem
-import com.divinelink.core.ui.EmptyContent
 import com.divinelink.core.ui.Previews
 import com.divinelink.core.ui.TestTags.MEDIA_LIST_TAG
+import com.divinelink.core.ui.blankslate.BlankSlate
 import com.divinelink.core.ui.components.Filter
 import com.divinelink.core.ui.components.FilterBar
 import com.divinelink.core.ui.components.LoadingContent
@@ -51,6 +52,7 @@ fun HomeContent(
   onNavigateToDetails: (MediaItem) -> Unit,
   onFilterClick: (Filter) -> Unit,
   onClearFiltersClick: () -> Unit,
+  onRetryClick: () -> Unit,
   onNavigateToSettings: () -> Unit,
 ) {
   val scrollBehavior = TopAppBarDefaults.enterAlwaysScrollBehavior(rememberTopAppBarState())
@@ -102,8 +104,11 @@ fun HomeContent(
         label = "HomeContentEmptyTransition",
       ) { isEmpty ->
         when (isEmpty) {
-          true -> viewState.emptyContentUiState?.let {
-            EmptyContent(it)
+          true -> if (viewState.blankSlate != null) {
+            BlankSlate(
+              uiState = viewState.blankSlate,
+              onRetry = viewState.retryAction?.let { onRetryClick },
+            )
           }
           false -> AnimatedContent(
             targetState = viewState.mode,
@@ -206,7 +211,12 @@ private fun HomeContentPreview() {
           filteredResults = null,
           isSearchLoading = false,
           query = "",
+          pages = mapOf(
+            HomePage.Popular to 1,
+            HomePage.Search to 1,
+          ),
           mode = HomeMode.Browser,
+          retryAction = null,
         ),
         onMarkAsFavoriteClicked = {},
         onLoadNextPage = {},
@@ -216,6 +226,7 @@ private fun HomeContentPreview() {
         onFilterClick = {},
         onClearFiltersClick = {},
         onNavigateToSettings = {},
+        onRetryClick = {},
       )
     }
   }

app/src/main/kotlin/com/andreolas/movierama/home/ui/HomeScreen.kt

@@ -61,5 +61,6 @@ fun HomeScreen(
     onNavigateToSettings = {
       navigator.navigate(SettingsScreenDestination())
     },
+    onRetryClick = viewModel::onRetryClick,
   )
 }

app/src/main/kotlin/com/andreolas/movierama/home/ui/HomeViewModel.kt

@@ -5,13 +5,15 @@ import androidx.lifecycle.viewModelScope
 import com.andreolas.movierama.home.domain.usecase.FetchMultiInfoSearchUseCase
 import com.andreolas.movierama.home.domain.usecase.GetFavoriteMoviesUseCase
 import com.andreolas.movierama.home.domain.usecase.GetPopularMoviesUseCase
+import com.divinelink.core.commons.ErrorHandler
 import com.divinelink.core.commons.domain.data
 import com.divinelink.core.domain.MarkAsFavoriteUseCase
 import com.divinelink.core.model.home.HomeMode
+import com.divinelink.core.model.home.HomePage
 import com.divinelink.core.model.media.MediaItem
 import com.divinelink.core.network.media.model.movie.MoviesRequestApi
 import com.divinelink.core.network.media.model.search.multi.MultiSearchRequestApi
-import com.divinelink.core.ui.UIText
+import com.divinelink.core.ui.blankslate.BlankSlateState
 import com.divinelink.core.ui.components.Filter
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.delay
@@ -24,16 +26,14 @@ import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 import timber.log.Timber
+import java.net.UnknownHostException
 
 class HomeViewModel(
   private val getPopularMoviesUseCase: GetPopularMoviesUseCase,
   private val fetchMultiInfoSearchUseCase: FetchMultiInfoSearchUseCase,
   private val markAsFavoriteUseCase: MarkAsFavoriteUseCase,
   private val getFavoriteMoviesUseCase: GetFavoriteMoviesUseCase,
 ) : ViewModel() {
-  private var currentPage: Int = 1
-  private var searchPage: Int = 1
-
   private var searchJob: Job? = null
 
   private var allowSearchResult: Boolean = true
@@ -53,26 +53,44 @@ class HomeViewModel(
   }
 
   private fun fetchPopularMovies() {
+    if (getPage(HomePage.Popular) == 1) {
+      _viewState.setLoading()
+    }
+
     viewModelScope.launch {
       getPopularMoviesUseCase.invoke(
         parameters = MoviesRequestApi(
-          page = currentPage,
+          page = getPage(HomePage.Popular),
         ),
       ).collectLatest { result ->
         result.onSuccess {
+          incrementPage(HomePage.Popular)
           _viewState.update { viewState ->
             viewState.copy(
               isLoading = false,
+              error = null,
+              retryAction = null,
               popularMovies = viewState.popularMovies.addMore(result.data),
             )
           }
         }.onFailure {
           _viewState.update { viewState ->
             viewState.copy(
               isLoading = false,
-              error = UIText.StringText(it.message ?: "Something went wrong."),
             )
           }
+          ErrorHandler.create(it) {
+            on<UnknownHostException> {
+              if (getPage(HomePage.Popular) == 1) {
+                _viewState.update { viewState ->
+                  viewState.copy(
+                    error = BlankSlateState.Offline,
+                    retryAction = HomeMode.Browser,
+                  )
+                }
+              }
+            }
+          }
         }
       }
     }
@@ -95,22 +113,20 @@ class HomeViewModel(
     when (viewState.value.mode) {
       HomeMode.Filtered -> return
       HomeMode.Browser -> if (viewState.value.popularMovies.shouldLoadMore) {
-        currentPage++
         fetchPopularMovies()
       }
       HomeMode.Search -> if (viewState.value.searchResults?.shouldLoadMore == true) {
-        searchPage++
         fetchFromSearchQuery(
           query = viewState.value.query,
-          page = searchPage,
+          page = getPage(HomePage.Search),
         )
       }
     }
   }
 
   fun onSearchMovies(query: String) {
     searchJob?.cancel()
-    searchPage = 1
+    resetPage(HomePage.Search)
     allowSearchResult = true
     if (query.isEmpty()) {
       onClearClicked()
@@ -123,7 +139,7 @@ class HomeViewModel(
       }
       searchJob = viewModelScope.launch {
         delay(timeMillis = 300)
-        if (cachedSearchResults.contains(query) && searchPage == 1) {
+        if (cachedSearchResults.contains(query) && getPage(HomePage.Search) == 1) {
           Timber.d("Fetching cached results")
           _viewState.update { viewState ->
             latestQuery = query
@@ -136,8 +152,9 @@ class HomeViewModel(
             )
           }
           // If cache found, set search page to last cached search page
-          searchPage = cachedSearchResults[query]?.page ?: 1
-          Timber.d("Setting page to: $searchPage")
+          // FIXME
+//          searchPage = cachedSearchResults[query]?.page ?: 1
+//          Timber.d("Setting page to: $searchPage")
         } else {
           Timber.d("Fetching data from web service..")
           fetchFromSearchQuery(query = query, page = 1)
@@ -148,7 +165,7 @@ class HomeViewModel(
 
   fun onClearClicked() {
     searchJob?.cancel()
-    searchPage = 1
+    resetPage(HomePage.Search)
     allowSearchResult = false
     latestQuery = null
     _viewState.update { viewState ->
@@ -174,8 +191,6 @@ class HomeViewModel(
     latestQuery = query
 
     viewModelScope.launch {
-      _viewState.setLoading()
-
       fetchMultiInfoSearchUseCase.invoke(
         parameters = MultiSearchRequestApi(
           query = query,
@@ -185,12 +200,15 @@ class HomeViewModel(
         .distinctUntilChanged()
         .collectLatest { result ->
           result.onSuccess {
+            incrementPage(HomePage.Search)
             if (allowSearchResult && result.data.query == latestQuery) {
               _viewState.update { viewState ->
                 viewState.copy(
                   isSearchLoading = false,
                   isLoading = false,
+                  error = null,
                   mode = HomeMode.Search,
+                  retryAction = null,
                   searchResults = if (isNewSearch) {
                     isNewSearch = false
                     MediaSection(
@@ -206,14 +224,32 @@ class HomeViewModel(
               }
             }
           }.onFailure {
-            _viewState.update { viewState ->
-              viewState.copy(
-                isSearchLoading = false,
-                error = UIText.StringText(it.message ?: "Something went wrong."),
-              )
-            }
+            handleSearchError(it)
+          }
+        }
+    }
+  }
+
+  private fun handleSearchError(it: Throwable) {
+    _viewState.update { viewState ->
+      viewState.copy(
+        isLoading = false,
+        isSearchLoading = false,
+      )
+    }
+    ErrorHandler.create(it) {
+      on<UnknownHostException> {
+        if (getPage(HomePage.Search) == 1) {
+          _viewState.update { viewState ->
+            viewState.copy(
+              mode = HomeMode.Search,
+              searchResults = null,
+              error = BlankSlateState.Offline,
+              retryAction = HomeMode.Search,
+            )
           }
         }
+      }
     }
   }
 
@@ -266,6 +302,19 @@ class HomeViewModel(
     }
   }
 
+  fun onRetryClick() {
+    when (viewState.value.retryAction) {
+      HomeMode.Browser -> fetchPopularMovies()
+      HomeMode.Search -> {
+        latestQuery = null
+        onSearchMovies(viewState.value.query)
+      }
+      else -> {
+        // Do nothing
+      }
+    }
+  }
+
   /**
    * Handles the filters for the liked movies.
    * This method fetches the liked movies from the database and updates the view state.
@@ -305,6 +354,8 @@ class HomeViewModel(
   private fun updateFilters(homeFilter: HomeFilter?) {
     _viewState.update { viewState ->
       viewState.copy(
+        // TODO add test
+        retryAction = null,
         filters = viewState.filters.map { currentFilter ->
           if (currentFilter.name == homeFilter?.filter?.name) {
             currentFilter.copy(isSelected = !currentFilter.isSelected)
@@ -324,6 +375,24 @@ class HomeViewModel(
       )
     }
   }
+
+  private fun incrementPage(page: HomePage) {
+    _viewState.update { viewState ->
+      viewState.copy(
+        pages = viewState.pages + (page to (viewState.pages[page] ?: 1) + 1),
+      )
+    }
+  }
+
+  private fun resetPage(page: HomePage) {
+    _viewState.update { viewState ->
+      viewState.copy(
+        pages = viewState.pages + (page to 1),
+      )
+    }
+  }
+
+  private fun getPage(page: HomePage): Int = viewState.value.pages[page] ?: 1
 }
 
 data class SearchCache(