feat(ui): add StationsScreen and StationsViewModel

app/src/main/java/com/radiola/ui/stations/StationsScreen.kt

@@ -0,0 +1,77 @@
+package com.radiola.ui.stations
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.grid.GridCells
+import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
+import androidx.compose.foundation.lazy.grid.items
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import com.radiola.ui.components.*
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun StationsScreen(
+    onStationClick: (Int) -> Unit,
+    modifier: Modifier = Modifier,
+    viewModel: StationsViewModel = hiltViewModel()
+) {
+    val stations by viewModel.stations.collectAsState()
+    val tags by viewModel.tags.collectAsState()
+    val searchQuery by viewModel.searchQuery.collectAsState()
+    val selectedTag by viewModel.selectedTag.collectAsState()
+    val isLoading by viewModel.isLoading.collectAsState()
+    val error by viewModel.error.collectAsState()
+
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text("Радио") },
+                colors = TopAppBarDefaults.topAppBarColors(
+                    containerColor = MaterialTheme.colorScheme.background
+                )
+            )
+        }
+    ) { padding ->
+        Column(
+            modifier = modifier
+                .fillMaxSize()
+                .padding(padding)
+        ) {
+            SearchBar(
+                query = searchQuery,
+                onQueryChange = viewModel::onSearchQueryChange,
+                modifier = Modifier.padding(16.dp)
+            )
+            FilterChips(
+                tags = tags,
+                selectedTag = selectedTag,
+                onTagSelected = viewModel::onTagSelected,
+                modifier = Modifier.padding(vertical = 8.dp)
+            )
+            when {
+                isLoading -> Box(modifier = Modifier.fillMaxSize(), contentAlignment = androidx.compose.ui.Alignment.Center) {
+                    CircularProgressIndicator()
+                }
+                error != null -> EmptyState(message = error!!)
+                stations.isEmpty() -> EmptyState(message = "Станции не найдены")
+                else -> LazyVerticalGrid(
+                    columns = GridCells.Fixed(2),
+                    modifier = Modifier.fillMaxSize(),
+                    contentPadding = PaddingValues(16.dp),
+                    horizontalArrangement = Arrangement.spacedBy(12.dp),
+                    verticalArrangement = Arrangement.spacedBy(12.dp)
+                ) {
+                    items(stations, key = { it.id }) { station ->
+                        StationCard(
+                            station = station,
+                            onClick = { onStationClick(station.id) }
+                        )
+                    }
+                }
+            }
+        }
+    }
+}

app/src/main/java/com/radiola/ui/stations/StationsViewModel.kt

@@ -0,0 +1,72 @@
+package com.radiola.ui.stations
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.radiola.domain.model.Station
+import com.radiola.domain.usecase.GetStationsUseCase
+import com.radiola.domain.usecase.PlayStationUseCase
+import com.radiola.domain.usecase.ToggleFavoriteUseCase
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.*
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+@HiltViewModel
+class StationsViewModel @Inject constructor(
+    private val getStationsUseCase: GetStationsUseCase,
+    private val playStationUseCase: PlayStationUseCase,
+    private val toggleFavoriteUseCase: ToggleFavoriteUseCase
+) : ViewModel() {
+
+    private val _searchQuery = MutableStateFlow("")
+    val searchQuery: StateFlow<String> = _searchQuery.asStateFlow()
+
+    private val _selectedTag = MutableStateFlow<String?>(null)
+    val selectedTag: StateFlow<String?> = _selectedTag.asStateFlow()
+
+    private val _isLoading = MutableStateFlow(false)
+    val isLoading: StateFlow<Boolean> = _isLoading.asStateFlow()
+
+    private val _error = MutableStateFlow<String?>(null)
+    val error: StateFlow<String?> = _error.asStateFlow()
+
+    val stations: StateFlow<List<Station>> = combine(
+        getStationsUseCase(),
+        _searchQuery,
+        _selectedTag
+    ) { allStations, query, tag ->
+        allStations
+            .filter { station ->
+                tag == null || station.tags.contains(tag) || station.genre.equals(tag, ignoreCase = true)
+            }
+            .filter { station ->
+                query.isBlank() ||
+                station.name.contains(query, ignoreCase = true) ||
+                station.genre.contains(query, ignoreCase = true)
+            }
+    }.stateIn(viewModelScope, SharingStarted.WhileSubscribed(5000), emptyList())
+
+    val tags: StateFlow<List<String>> = getStationsUseCase()
+        .map { stations -> stations.flatMap { it.tags }.distinct().sorted() }
+        .stateIn(viewModelScope, SharingStarted.WhileSubscribed(5000), emptyList())
+
+    fun onSearchQueryChange(query: String) {
+        _searchQuery.value = query
+    }
+
+    fun onTagSelected(tag: String?) {
+        _selectedTag.value = tag
+    }
+
+    fun playStation(station: Station) {
+        viewModelScope.launch {
+            playStationUseCase(station)
+        }
+    }
+
+    fun toggleFavorite(station: Station) {
+        viewModelScope.launch {
+            toggleFavoriteUseCase(station)
+        }
+    }
+}