Better error handling

app/src/main/java/net/buzzert/kordophonedroid/KordophoneApplication.kt

@@ -1,16 +1,13 @@
 package net.buzzert.kordophonedroid
 
 import android.app.Application
+import androidx.hilt.navigation.compose.hiltViewModel
 import dagger.hilt.android.HiltAndroidApp
 import net.buzzert.kordophonedroid.data.AppContainer
-import net.buzzert.kordophonedroid.data.AppContainerImpl
 
 @HiltAndroidApp
 class KordophoneApplication : Application() {
-    lateinit var container: AppContainer
-
     override fun onCreate() {
         super.onCreate()
-        container = AppContainerImpl()
     }
 }

app/src/main/java/net/buzzert/kordophonedroid/MainActivity.kt

@@ -4,7 +4,6 @@ import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import dagger.hilt.android.AndroidEntryPoint
-import net.buzzert.kordophonedroid.data.AppContainerImpl
 import net.buzzert.kordophonedroid.ui.KordophoneApp
 
 @AndroidEntryPoint
@@ -12,9 +11,8 @@ class MainActivity : ComponentActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
-        val container = (application as KordophoneApplication).container
         setContent {
-            KordophoneApp(appContainer = container)
+            KordophoneApp()
         }
     }
 }

app/src/main/java/net/buzzert/kordophonedroid/data/AppContainerImpl.kt

@@ -1,18 +1,15 @@
 package net.buzzert.kordophonedroid.data
 
+import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelStore
 import androidx.lifecycle.ViewModelStoreOwner
+import dagger.hilt.android.lifecycle.HiltViewModel
 import net.buzzert.kordophone.backend.server.ChatRepository
+import javax.inject.Inject
 
-interface AppContainer: ViewModelStoreOwner {
+@HiltViewModel
+class AppContainer @Inject constructor(
     val repository: ChatRepository
-}
+) : ViewModel() {
-
-class AppContainerImpl() : AppContainer {
-    override val repository: ChatRepository
-        get() = TODO("Not yet implemented")
-
-    override val viewModelStore: ViewModelStore
-        get() = TODO("Not yet implemented")
-}
 
+}

app/src/main/java/net/buzzert/kordophonedroid/ui/KordophoneApp.kt

@@ -1,11 +1,20 @@
 package net.buzzert.kordophonedroid.ui
 
+import androidx.compose.material.AlertDialog
+import androidx.compose.material.Button
 import androidx.compose.material.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
 import androidx.navigation.compose.rememberNavController
+import kotlinx.coroutines.flow.collectLatest
+import net.buzzert.kordophone.backend.server.ChatRepository
 
 import net.buzzert.kordophonedroid.data.AppContainer
 import net.buzzert.kordophonedroid.ui.theme.KordophoneTheme
@@ -19,12 +28,35 @@ sealed class Destination(val route: String) {
     }
 }
 
+@Composable
+fun ErrorDialog(title: String, body: String, onDismiss: () -> Unit) {
+    AlertDialog(
+        onDismissRequest = { onDismiss() },
+        title = { Text(title) },
+        text = { Text(body) },
+        confirmButton = {
+            Button(onClick = { onDismiss() }) {
+                Text("OK")
+            }
+        }
+    )
+}
+
 @Composable
 fun KordophoneApp(
-    appContainer: AppContainer,
+    appContainer: AppContainer = hiltViewModel(),
 ) {
     KordophoneTheme {
         val navController = rememberNavController()
+        val errorVisible = remember { mutableStateOf<ChatRepository.Error?>(null)  }
+        val error = appContainer.repository.errorEncounteredChannel.collectAsStateWithLifecycle(
+            initialValue = null
+        )
+        
+        LaunchedEffect(key1 = error.value) {
+            errorVisible.value = error.value
+        }
+
         NavHost(
             navController = navController,
             startDestination = Destination.ConversationList.route,
@@ -42,5 +74,11 @@ fun KordophoneApp(
                 })
             }
         }
+
+        errorVisible.value?.let {
+            ErrorDialog(title = it.title, body = it.description) {
+                errorVisible.value = null
+            }
+        }
     }
 }

backend/src/main/java/net/buzzert/kordophone/backend/server/ChatRepository.kt

@@ -6,6 +6,7 @@ import kotlinx.coroutines.Job
 import kotlinx.coroutines.cancel
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.channels.consumeEach
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.SharedFlow
@@ -20,6 +21,7 @@ import net.buzzert.kordophone.backend.model.Conversation
 import net.buzzert.kordophone.backend.model.GUID
 import net.buzzert.kordophone.backend.model.Message
 import net.buzzert.kordophone.backend.model.UpdateItem
+import java.lang.Error
 import java.net.URL
 import java.util.Queue
 import java.util.UUID
@@ -33,6 +35,16 @@ class ChatRepository(
     private val apiClient: APIClient,
     private val database: CachedChatDatabase,
 ) {
+    sealed class Error {
+        open val title: String = "Error"
+        open val description: String = "Generic Error"
+
+        data class ConnectionError(val exception: java.lang.Exception): Error() {
+            override val title: String = "Connection Error"
+            override val description: String = exception.message ?: "???"
+        }
+    }
+
     // All (Cached) Conversations
     val conversations: List<Conversation>
         get() = database.fetchConversations()
@@ -46,6 +58,10 @@ class ChatRepository(
         get() = database.conversationChanges
             .onEach { Log.d(REPO_LOG, "Got database conversations changed") }
 
+    // Errors channel
+    val errorEncounteredChannel: SharedFlow<Error>
+        get() = _errorEncounteredChannel
+
     fun messagesChanged(conversation: Conversation): Flow<List<Message>> =
         database.messagesChanged(conversation)
 
@@ -72,6 +88,7 @@ class ChatRepository(
     private val outgoingMessageQueue: ArrayBlockingQueue<OutgoingMessageInfo> = ArrayBlockingQueue(16)
     private var outgoingMessageThread: Thread? = null
     private val _messageDeliveredChannel = MutableSharedFlow<MessageDeliveredEvent>()
+    private val _errorEncounteredChannel = MutableSharedFlow<Error>()
 
     private val updateMonitor = UpdateMonitor(apiClient)
     private var updateWatchJob: Job? = null
@@ -126,7 +143,7 @@ class ChatRepository(
         return database.fetchMessages(conversation)
     }
 
-    suspend fun synchronize() {
+    suspend fun synchronize() = try {
         Log.d(REPO_LOG, "Synchronizing conversations")
 
         // Sync conversations
@@ -139,13 +156,17 @@ class ChatRepository(
         for (conversation in sortedConversations.take(CONVERSATION_MESSAGE_SYNC_COUNT)) {
             synchronizeConversation(conversation)
         }
+    } catch (e: java.lang.Exception) {
+        _errorEncounteredChannel.emit(Error.ConnectionError(e))
     }
 
-    suspend fun synchronizeConversation(conversation: Conversation) {
+    suspend fun synchronizeConversation(conversation: Conversation) = try {
         // TODO: Should only fetch messages after the last GUID we know about.
         // But keep in mind that outgoing message GUIDs are fake...
         val messages = fetchMessages(conversation, limit = 15)
         database.writeMessages(messages, conversation)
+    } catch (e: java.lang.Exception) {
+        _errorEncounteredChannel.emit(Error.ConnectionError(e))
     }
 
     fun close() {
@@ -187,6 +208,11 @@ class ChatRepository(
         database.writeMessages(listOf(event.message), event.conversation, outgoing = true)
     }
 
+    private suspend fun retryMessageSend(info: OutgoingMessageInfo) {
+        delay(5000L)
+        outgoingMessageQueue.add(info)
+    }
+
     private fun outgoingMessageQueueMain() {
         Log.d(REPO_LOG, "Outgoing Message Queue Main")
         while (true) {
@@ -198,36 +224,41 @@ class ChatRepository(
 
                     Log.d(REPO_LOG, "Sending message to $conversation: $outgoingMessage")
 
-                    val result = apiInterface.sendMessage(
+                    try {
-                        SendMessageRequest(
+                        val result = apiInterface.sendMessage(
-                            conversationGUID = conversation.guid,
+                            SendMessageRequest(
-                            body = outgoingMessage.text,
+                                conversationGUID = conversation.guid,
-                            transferGUIDs = null,
+                                body = outgoingMessage.text,
-                        )
+                                transferGUIDs = null,
-                    )
-
-                    if (result.isSuccessful) {
-                        val messageGuid = result.body()?.sentMessageGUID ?: outgoingMessage.guid
-                        Log.d(REPO_LOG, "Successfully sent message: $messageGuid")
-
-                        val newMessage = Message(
-                            guid = messageGuid,
-                            text = outgoingMessage.text,
-                            sender = null,
-                            conversation = it.conversation,
-                            date = outgoingMessage.date
-                        )
-
-                        _messageDeliveredChannel.emit(
-                            MessageDeliveredEvent(
-                                newMessage,
-                                conversation,
-                                requestGuid
                             )
                         )
-                    } else {
+
-                        Log.e(REPO_LOG, "Error sending message. Enqueuing for retry.")
+                        if (result.isSuccessful) {
-                        outgoingMessageQueue.add(it)
+                            val messageGuid = result.body()?.sentMessageGUID ?: outgoingMessage.guid
+                            Log.d(REPO_LOG, "Successfully sent message: $messageGuid")
+
+                            val newMessage = Message(
+                                guid = messageGuid,
+                                text = outgoingMessage.text,
+                                sender = null,
+                                conversation = it.conversation,
+                                date = outgoingMessage.date
+                            )
+
+                            _messageDeliveredChannel.emit(
+                                MessageDeliveredEvent(
+                                    newMessage,
+                                    conversation,
+                                    requestGuid
+                                )
+                            )
+                        } else {
+                            Log.e(REPO_LOG, "Error sending message. Enqueuing for retry.")
+                            retryMessageSend(it)
+                        }
+                    } catch (e: java.lang.Exception) {
+                        Log.e(REPO_LOG, "Error sending message: (${e.message}). Enqueuing for retry in 5 sec.")
+                        retryMessageSend(it)
                     }
                 }
             }

backend/src/main/java/net/buzzert/kordophone/backend/server/UpdateMonitor.kt

@@ -3,8 +3,12 @@ package net.buzzert.kordophone.backend.server
 import android.util.Log
 import com.google.gson.Gson
 import com.google.gson.reflect.TypeToken
+import kotlinx.coroutines.DelicateCoroutinesApi
+import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.launch
 import kotlinx.coroutines.runBlocking
 import net.buzzert.kordophone.backend.model.Conversation
 import net.buzzert.kordophone.backend.model.Message
@@ -15,6 +19,7 @@ import okhttp3.WebSocketListener
 import okio.ByteString
 import retrofit2.converter.gson.GsonConverterFactory
 import java.lang.reflect.Type
+import kotlin.time.Duration
 
 const val UPMON_LOG: String = "UpdateMonitor"
 
@@ -30,6 +35,7 @@ class UpdateMonitor(private val client: APIClient) : WebSocketListener() {
     private val gson: Gson = Gson()
     private val updateItemsType: Type = object : TypeToken<ArrayList<UpdateItem>>() {}.type
     private var webSocket: WebSocket? = null
+    private var needsSocketReconnect: Boolean = false
 
     private val _conversationChanged: MutableSharedFlow<Conversation> = MutableSharedFlow()
     private val _messageAdded: MutableSharedFlow<Message> = MutableSharedFlow()
@@ -62,6 +68,22 @@ class UpdateMonitor(private val client: APIClient) : WebSocketListener() {
         }
     }
 
+    @OptIn(DelicateCoroutinesApi::class)
+    private fun setNeedsSocketReconnect() {
+        if (!needsSocketReconnect) {
+            needsSocketReconnect = true
+
+            GlobalScope.launch {
+                needsSocketReconnect = false
+
+                // Delay 5 seconds
+                delay(5000L)
+
+                beginMonitoringUpdates()
+            }
+        }
+    }
+
     // <WebSocketListener>
 
     override fun onOpen(webSocket: WebSocket, response: Response) {
@@ -72,11 +94,13 @@ class UpdateMonitor(private val client: APIClient) : WebSocketListener() {
     override fun onClosed(webSocket: WebSocket, code: Int, reason: String) {
         super.onClosed(webSocket, code, reason)
         Log.d(UPMON_LOG, "Update monitor socket closed")
+        setNeedsSocketReconnect()
     }
 
     override fun onFailure(webSocket: WebSocket, t: Throwable, response: Response?) {
         super.onFailure(webSocket, t, response)
-        Log.d(UPMON_LOG, "Update monitor socket failure: ${t.message} :: Response: ${response?.body()}")
+        Log.d(UPMON_LOG, "Update monitor socket failure: ${t.message} :: Response: ${response?.body()}. Reconnecting in 5 seconds.")
+        setNeedsSocketReconnect()
     }
 
     override fun onMessage(webSocket: WebSocket, text: String) {