Implement error handling showing as snackbar notifications

app/src/main/java/com/github/feelbeatapp/androidclient/di/AppModule.kt

@@ -1,11 +1,15 @@
 package com.github.feelbeatapp.androidclient.di
 
+import androidx.compose.material3.SnackbarHostState
 import com.github.feelbeatapp.androidclient.BuildConfig
 import com.github.feelbeatapp.androidclient.auth.AuthManager
 import com.github.feelbeatapp.androidclient.auth.OauthConfig
 import com.github.feelbeatapp.androidclient.auth.spotify.SpotifyAuthManager
 import com.github.feelbeatapp.androidclient.auth.storage.AuthStorage
 import com.github.feelbeatapp.androidclient.auth.storage.PreferencesAuthStorage
+import com.github.feelbeatapp.androidclient.error.ErrorEmitter
+import com.github.feelbeatapp.androidclient.error.ErrorHandler
+import com.github.feelbeatapp.androidclient.error.ErrorReceiver
 import com.github.feelbeatapp.androidclient.network.api.FeelBeatApi
 import com.github.feelbeatapp.androidclient.network.api.KtorFeelBeatApi
 import com.github.feelbeatapp.androidclient.network.fullduplex.NetworkAgent
@@ -37,6 +41,8 @@ abstract class AppModule {
                 install(ContentNegotiation) { json(Json { ignoreUnknownKeys = true }) }
             }
 
+        private val errorHandler = ErrorHandler()
+
         @Provides
         @Singleton
         fun provideHttpClient(): HttpClient {
@@ -68,6 +74,18 @@ abstract class AppModule {
         fun provideApiUrl(): String {
             return BuildConfig.API_URL
         }
+
+        @Provides
+        @Singleton
+        fun provideErrorEmitter(): ErrorEmitter {
+            return errorHandler
+        }
+
+        @Provides
+        @Singleton
+        fun provideErrorReceiver(): ErrorReceiver {
+            return errorHandler
+        }
     }
 
     @Singleton @Binds abstract fun bindAuthManager(authManager: SpotifyAuthManager): AuthManager

app/src/main/java/com/github/feelbeatapp/androidclient/error/ErrorCode.kt

@@ -1,5 +1,7 @@
 package com.github.feelbeatapp.androidclient.error
 
+import com.github.feelbeatapp.androidclient.R
+
 enum class ErrorCode {
     AUTHORIZATION_SERVER_UNREACHABLE,
     AUTHORIZATION_ACCESS_TOKEN_ERROR,
@@ -8,4 +10,15 @@ enum class ErrorCode {
     FEELBEAT_SERVER_UNREACHABLE,
     FEELBEAT_SERVER_ERROR,
     FEELBEAT_SERVER_INCORRECT_RESPONSE_FORMAT,
+    INCORRECT_PLAYLIST_LINK;
+
+    fun toStringId(): Int {
+        return when (this) {
+            AUTHORIZATION_SERVER_UNREACHABLE -> R.string.authorization_server_unreachable
+            FEELBEAT_SERVER_UNREACHABLE -> R.string.feelbeat_server_unreachable
+            INCORRECT_PLAYLIST_LINK -> R.string.incorrect_playlist_link
+            FEELBEAT_SERVER_ERROR -> R.string.feelbeat_server_error
+            else -> R.string.unexpected_error
+        }
+    }
 }

app/src/main/java/com/github/feelbeatapp/androidclient/error/ErrorEmitter.kt

@@ -0,0 +1,7 @@
+package com.github.feelbeatapp.androidclient.error
+
+import kotlinx.coroutines.flow.SharedFlow
+
+interface ErrorEmitter {
+    val errors: SharedFlow<FeelBeatException>
+}

app/src/main/java/com/github/feelbeatapp/androidclient/error/ErrorHandler.kt

@@ -0,0 +1,14 @@
+package com.github.feelbeatapp.androidclient.error
+
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.asSharedFlow
+import javax.inject.Inject
+
+class ErrorHandler @Inject constructor() : ErrorEmitter, ErrorReceiver {
+    private val _errors = MutableSharedFlow<FeelBeatException>()
+    override val errors = _errors.asSharedFlow()
+
+    override suspend fun submitError(exception: FeelBeatException) {
+        _errors.emit(exception)
+    }
+}

app/src/main/java/com/github/feelbeatapp/androidclient/error/ErrorReceiver.kt

@@ -0,0 +1,5 @@
+package com.github.feelbeatapp.androidclient.error
+
+interface ErrorReceiver {
+    suspend fun submitError(exception: FeelBeatException)
+}

app/src/main/java/com/github/feelbeatapp/androidclient/error/FeelBeatException.kt

@@ -1,6 +1,6 @@
 package com.github.feelbeatapp.androidclient.error
 
-class FeelBeatException(val code: ErrorCode, debugMessage: String?, cause: Throwable?) :
+open class FeelBeatException(val code: ErrorCode, debugMessage: String?, cause: Throwable?) :
     Exception(debugMessage, cause) {
     constructor(code: ErrorCode, debugMessage: String) : this(code, debugMessage, null)
 

app/src/main/java/com/github/feelbeatapp/androidclient/error/FeelBeatServerException.kt

@@ -0,0 +1,4 @@
+package com.github.feelbeatapp.androidclient.error
+
+class FeelBeatServerException(val serverMessage: String) :
+    FeelBeatException(ErrorCode.FEELBEAT_SERVER_ERROR)

app/src/main/java/com/github/feelbeatapp/androidclient/network/api/KtorFeelBeatApi.kt

@@ -3,6 +3,7 @@ package com.github.feelbeatapp.androidclient.network.api
 import com.github.feelbeatapp.androidclient.auth.AuthManager
 import com.github.feelbeatapp.androidclient.error.ErrorCode
 import com.github.feelbeatapp.androidclient.error.FeelBeatException
+import com.github.feelbeatapp.androidclient.error.FeelBeatServerException
 import com.github.feelbeatapp.androidclient.network.api.payloads.CreateRoomPayload
 import com.github.feelbeatapp.androidclient.network.api.responses.CreateRoomResponse
 import com.github.feelbeatapp.androidclient.ui.app.model.RoomSettings
@@ -48,7 +49,7 @@ constructor(
             }
 
         if (res.status != HttpStatusCode.OK) {
-            throw FeelBeatException(ErrorCode.FEELBEAT_SERVER_ERROR, res.bodyAsText())
+            throw FeelBeatServerException(res.bodyAsText())
         }
 
         val (roomId) =

app/src/main/java/com/github/feelbeatapp/androidclient/ui/app/AppScreen.kt

@@ -18,6 +18,7 @@ import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.ModalBottomSheet
 import androidx.compose.material3.Scaffold
+import androidx.compose.material3.SnackbarHost
 import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.runtime.Composable
@@ -78,6 +79,7 @@ fun AppScreen(
                 onNavigateBack = onNavigateBack,
             )
         },
+        snackbarHost = { SnackbarHost(hostState = appViewModel.snackBarHost) },
         bottomBar = { bottomBar() },
         modifier = Modifier.fillMaxSize(),
     ) { padding ->

app/src/main/java/com/github/feelbeatapp/androidclient/ui/app/AppViewModel.kt

@@ -1,28 +1,56 @@
 package com.github.feelbeatapp.androidclient.ui.app
 
+import android.content.Context
+import androidx.compose.material3.SnackbarHostState
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.github.feelbeatapp.androidclient.auth.AuthManager
+import com.github.feelbeatapp.androidclient.error.ErrorEmitter
+import com.github.feelbeatapp.androidclient.error.FeelBeatException
+import com.github.feelbeatapp.androidclient.error.FeelBeatServerException
 import com.github.feelbeatapp.androidclient.network.spotify.SpotifyAPI
 import dagger.hilt.android.lifecycle.HiltViewModel
-import javax.inject.Inject
+import dagger.hilt.android.qualifiers.ApplicationContext
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.launch
+import javax.inject.Inject
 
 data class PlayerIdentity(val name: String, val imageUrl: String)
 
 @HiltViewModel
 class AppViewModel
 @Inject
-constructor(private val authManager: AuthManager, private val spotifyAPI: SpotifyAPI) :
-    ViewModel() {
+constructor(
+    @ApplicationContext private val ctx: Context,
+    private val authManager: AuthManager,
+    private val spotifyAPI: SpotifyAPI,
+    private val errorEmitter: ErrorEmitter,
+) : ViewModel() {
     private val _playerIdentity = MutableStateFlow<PlayerIdentity?>(null)
     val playerIdentity = _playerIdentity.asStateFlow()
 
+    val snackBarHost = SnackbarHostState()
+
     init {
         loadPlayerIdentity()
+        handleErrors()
+    }
+
+    private fun handleErrors() {
+        viewModelScope.launch(Dispatchers.Default) {
+            errorEmitter.errors.collect {
+                snackBarHost.showSnackbar(formatException(it), withDismissAction = true)
+            }
+        }
+    }
+
+    private fun formatException(exception: FeelBeatException): String {
+        return when (exception) {
+            is FeelBeatServerException ->  ctx.getString(exception.code.toStringId(), exception.serverMessage)
+            else -> ctx.getString(exception.code.toStringId())
+        }
     }
 
     private fun loadPlayerIdentity() {

app/src/main/java/com/github/feelbeatapp/androidclient/ui/app/roomsettings/screens/NewRoomSettingsScreen.kt

@@ -31,8 +31,8 @@ fun NewRoomSettingsScreen(
     newRoomSettingsViewModel: NewRoomSettingsViewModel = hiltViewModel(),
     modifier: Modifier = Modifier,
 ) {
-    val roomCreationState by newRoomSettingsViewModel.roomCreationState.collectAsState()
     val createdRoomId by newRoomSettingsViewModel.roomCreated.collectAsState(null)
+    val loading by newRoomSettingsViewModel.loading.collectAsState()
 
     LaunchedEffect(createdRoomId) {
         val roomId = createdRoomId
@@ -47,9 +47,7 @@ fun NewRoomSettingsScreen(
     ) {
         SettingsControls(viewModel = newRoomSettingsViewModel)
 
-        Text(roomCreationState.errorMessage ?: "")
-
-        if (roomCreationState.loading) {
+        if (loading) {
             Row(horizontalArrangement = Arrangement.Center, modifier = Modifier.fillMaxWidth()) {
                 CircularProgressIndicator(
                     color = MaterialTheme.colorScheme.secondary,

app/src/main/java/com/github/feelbeatapp/androidclient/ui/app/roomsettings/viewmodels/NewRoomSettingsViewModel.kt

@@ -1,37 +1,49 @@
 package com.github.feelbeatapp.androidclient.ui.app.roomsettings.viewmodels
 
 import androidx.lifecycle.viewModelScope
+import com.github.feelbeatapp.androidclient.error.ErrorCode
+import com.github.feelbeatapp.androidclient.error.ErrorReceiver
+import com.github.feelbeatapp.androidclient.error.FeelBeatException
 import com.github.feelbeatapp.androidclient.network.api.FeelBeatApi
 import dagger.hilt.android.lifecycle.HiltViewModel
+import io.ktor.http.Url
 import javax.inject.Inject
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.asSharedFlow
 import kotlinx.coroutines.flow.asStateFlow
-import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.launch
 
-data class RoomCreationState(val errorMessage: String?, val loading: Boolean = false)
+const val SPOTIFY_PLAYLIST_HOST = "open.spotify.com"
 
 @HiltViewModel
-class NewRoomSettingsViewModel @Inject constructor(private val feelBeatApi: FeelBeatApi) :
+class NewRoomSettingsViewModel
+@Inject
+constructor(private val feelBeatApi: FeelBeatApi, private val errorReceiver: ErrorReceiver) :
     RoomSettingsViewModel() {
-    private val _roomCreationState = MutableStateFlow<RoomCreationState>(RoomCreationState(null))
-    val roomCreationState = _roomCreationState.asStateFlow()
+    private val _loading = MutableStateFlow(false)
+    val loading = _loading.asStateFlow()
 
     private val _roomCreated = MutableSharedFlow<String?>()
     val roomCreated = _roomCreated.asSharedFlow()
 
     fun createRoom() {
         viewModelScope.launch(Dispatchers.IO) {
-            _roomCreationState.update { it.copy(loading = true) }
+            val url = Url(roomSettings.value.playlistLink)
+            if (url.host != SPOTIFY_PLAYLIST_HOST || url.segments.isEmpty()) {
+                errorReceiver.submitError(FeelBeatException(ErrorCode.INCORRECT_PLAYLIST_LINK))
+                return@launch
+            }
+
+            _loading.value = true
             try {
                 val roomId = feelBeatApi.createRoom(roomSettings.value)
                 _roomCreated.emit(roomId)
-                _roomCreationState.update { it.copy(loading = false) }
-            } catch (e: Throwable) {
-                _roomCreationState.update { it.copy(errorMessage = e.message, loading = false) }
+            } catch (e: FeelBeatException) {
+                errorReceiver.submitError(e)
+            } finally {
+                _loading.value = false
             }
         }
     }

app/src/main/res/values/strings.xml

@@ -32,6 +32,10 @@
     <string name="ups_that_s_not_correct_answer">Ups, that\'s not correct answer</string>
     <string name="time_left">time left</string>
     <string name="authorization_server_unreachable">Authorization server is unreachable</string>
+    <string name="feelbeat_server_unreachable">FeelBeat server is unreachable</string>
+    <string name="feelbeat_server_error">Server error: %1$s</string>
+    <string name="unexpected_error">Unexpected error occurred</string>
+    <string name="incorrect_playlist_link">Make sure playlist link is valid</string>
     <string name="base_points">With how many points you starting to guess</string>
     <string name="incorrectGuessPenalty">How many points you will loose after incorrect guess</string>
     <string name="get_ready">Get ready</string>