feat: auth screen with auto-redirect, sync favorites/history with backend

app/src/main/java/com/radiola/ui/favorites/FavoritesScreen.kt

@@ -12,6 +12,7 @@ import androidx.hilt.navigation.compose.hiltViewModel
 import com.radiola.domain.model.Station
 import com.radiola.ui.components.EmptyState
 import com.radiola.ui.components.StationCard
+import androidx.compose.foundation.layout.Arrangement
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -21,6 +22,7 @@ fun FavoritesScreen(
     viewModel: FavoritesViewModel = hiltViewModel()
 ) {
     val favorites by viewModel.favorites.collectAsState()
+    val favoriteIds by viewModel.favoriteIds.collectAsState()
 
     Scaffold(
         topBar = {
@@ -50,7 +52,9 @@ fun FavoritesScreen(
                 items(favorites, key = { it.id }) { station ->
                     StationCard(
                         station = station,
-                        onClick = { onStationClick(station) }
+                        isFavorite = favoriteIds.contains(station.id),
+                        onClick = { onStationClick(station) },
+                        onFavoriteClick = { viewModel.toggleFavorite(station) }
                     )
                 }
             }

app/src/main/java/com/radiola/ui/favorites/FavoritesViewModel.kt

@@ -4,17 +4,43 @@ import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.radiola.domain.model.Station
 import com.radiola.domain.repository.FavoritesRepository
+import com.radiola.domain.usecase.ToggleFavoriteUseCase
+import com.radiola.domain.usecase.auth.PushFavoriteUseCase
+import com.radiola.domain.usecase.auth.SyncFavoritesUseCase
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.stateIn
+import kotlinx.coroutines.launch
 import javax.inject.Inject
 
 @HiltViewModel
 class FavoritesViewModel @Inject constructor(
-    favoritesRepository: FavoritesRepository
+    private val favoritesRepository: FavoritesRepository,
+    private val toggleFavoriteUseCase: ToggleFavoriteUseCase,
+    private val pushFavoriteUseCase: PushFavoriteUseCase,
+    private val syncFavoritesUseCase: SyncFavoritesUseCase
 ) : ViewModel() {
 
     val favorites: StateFlow<List<Station>> = favoritesRepository.getFavorites()
         .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5000), emptyList())
+
+    val favoriteIds: StateFlow<Set<Int>> = favoritesRepository.getFavorites()
+        .map { list -> list.map { it.id }.toSet() }
+        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5000), emptySet())
+
+    init {
+        viewModelScope.launch {
+            syncFavoritesUseCase()
+        }
+    }
+
+    fun toggleFavorite(station: Station) {
+        viewModelScope.launch {
+            val currentlyFavorite = favoriteIds.value.contains(station.id)
+            toggleFavoriteUseCase(station)
+            pushFavoriteUseCase(station.id, !currentlyFavorite)
+        }
+    }
 }