Implements message watching per conversation

backend/src/main/java/net/buzzert/kordophone/backend/db/CachedChatDatabase.kt

@@ -3,6 +3,7 @@ package net.buzzert.kordophone.backend.db
 import io.realm.kotlin.Realm
 import io.realm.kotlin.RealmConfiguration
 import io.realm.kotlin.UpdatePolicy
+import io.realm.kotlin.ext.toRealmList
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.asFlow
 import kotlinx.coroutines.flow.map
@@ -10,7 +11,9 @@ import net.buzzert.kordophone.backend.db.model.Conversation
 import net.buzzert.kordophone.backend.db.model.Message
 import net.buzzert.kordophone.backend.db.model.toDatabaseConversation
 import net.buzzert.kordophone.backend.db.model.toDatabaseMessage
+import net.buzzert.kordophone.backend.db.model.toRealmInstant
 import net.buzzert.kordophone.backend.model.GUID
+import java.lang.IllegalArgumentException
 import net.buzzert.kordophone.backend.model.Conversation as ModelConversation
 import net.buzzert.kordophone.backend.model.Message as ModelMessage
 
@@ -36,28 +39,51 @@ class CachedChatDatabase (private val realmConfig: RealmConfiguration) {
         }
     }
 
+    private val realm = Realm.open(realmConfig)
+
     // Flow for watching changes to the database
     val conversationChanges: Flow<List<ModelConversation>>
         get() = realm.query(Conversation::class).find().asFlow().map {
             it.list.map { it.toConversation() }
         }
 
-    // For for watching messages added to the database
+    // Flow for watching for message changes for a given conversation
-    val messagesAdded: Flow<List<ModelMessage>>
+    fun messagesChanged(conversation: ModelConversation): Flow<List<ModelMessage>> {
-        get() = realm.query(Message::class).find().asFlow().map {
+        return realm.query(Conversation::class, "guid == '${conversation.guid}'")
-            it.list.map { it.toMessage() }
+            .find()
+            .first()
+            .messages
+            .asFlow()
+            .map { it.list.map { it.toMessage(conversation) } }
     }
 
-    private val realm = Realm.open(realmConfig)
+    fun writeConversations(conversations: List<ModelConversation>) = realm.writeBlocking {
+        val dbConversations = conversations
+            // Convert to database conversations
+            .map { it.toDatabaseConversation() }
+
+            // Look for existing conversations, if applicable
+            .map {
+                try {
+                    val existingConvo = getConversationByGuid(it.guid)
+
+                    // Update existing record
+                    findLatest(existingConvo)?.apply {
+                        displayName = it.displayName
+                        participants = it.participants
+                        date = it.date
+                        unreadCount = it.unreadCount
+                    } ?: existingConvo
+                } catch (e: NoSuchElementException) {
+                    // This means object is unmanaged (i.e. it's new)
+                    it
+                }
+            }
 
-    fun writeConversations(conversations: List<ModelConversation>) {
-        val dbConversations = conversations.map { it.toDatabaseConversation() }
-        realm.writeBlocking {
         dbConversations.forEach {
             copyToRealm(it, updatePolicy = UpdatePolicy.ALL)
         }
     }
-    }
 
     fun fetchConversations(): List<ModelConversation> {
         val items = realm.query(Conversation::class).find()
@@ -67,13 +93,18 @@ class CachedChatDatabase (private val realmConfig: RealmConfiguration) {
     fun writeMessages(messages: List<ModelMessage>, conversation: ModelConversation) {
         val dbConversation = getConversationByGuid(conversation.guid)
         realm.writeBlocking {
-            findLatest(dbConversation)?.messages?.addAll(messages.map { it.toDatabaseMessage() })
+            val dbMessages = messages
+                .map { it.toDatabaseMessage() }
+                .map { copyToRealm(it, updatePolicy = UpdatePolicy.ALL) }
+
+            val obj = findLatest(dbConversation)
+            obj!!.messages.addAll(dbMessages)
         }
     }
 
     fun fetchMessages(conversation: ModelConversation): List<ModelMessage> {
         val dbConversation = getConversationByGuid(conversation.guid)
-        return dbConversation.messages.map { it.toMessage() }
+        return dbConversation.messages.map { it.toMessage(dbConversation.toConversation()) }
     }
 
     fun close() {

backend/src/main/java/net/buzzert/kordophone/backend/db/model/Conversation.kt

@@ -66,3 +66,4 @@ fun ModelConversation.toDatabaseConversation(): Conversation {
         guid = from.guid
     }
 }
+

backend/src/main/java/net/buzzert/kordophone/backend/db/model/Message.kt

@@ -21,7 +21,7 @@ open class Message(
     var sender: String?,
     var date: RealmInstant,
 
-    var conversation: Conversation?,
+    var conversationGUID: GUID,
 ): RealmObject
 {
     constructor() : this(
@@ -29,10 +29,10 @@ open class Message(
         text = "",
         sender = null,
         date = RealmInstant.now(),
-        conversation = null,
+        conversationGUID = ObjectId().toString(),
     )
 
-    fun toMessage(parentConversation: ModelConversation = conversation!!.toConversation()): ModelMessage {
+    fun toMessage(parentConversation: ModelConversation): ModelMessage {
         return ModelMessage(
             text = text,
             guid = guid,
@@ -50,6 +50,6 @@ fun ModelMessage.toDatabaseMessage(): Message {
         guid = from.guid
         sender = from.sender
         date = from.date.toInstant().toRealmInstant()
-        conversation = from.conversation.toDatabaseConversation()
+        conversationGUID = from.conversation.guid
     }
 }

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

@@ -1,24 +1,31 @@
 package net.buzzert.kordophone.backend.server
 
 import android.util.Log
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.cancel
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.launch
 import kotlinx.coroutines.runBlocking
 import net.buzzert.kordophone.backend.db.CachedChatDatabase
 import net.buzzert.kordophone.backend.events.MessageDeliveredEvent
 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.net.URL
 import java.util.Queue
 import java.util.UUID
 import java.util.concurrent.ArrayBlockingQueue
+import java.util.concurrent.CancellationException
 
 const val REPO_LOG: String = "ChatRepository"
 const val CONVERSATION_MESSAGE_SYNC_COUNT = 10
 
 class ChatRepository(
-    private val apiInterface: APIInterface,
+    private val apiClient: APIClient,
     private val database: CachedChatDatabase,
 ) {
     // All (Cached) Conversations
@@ -32,8 +39,21 @@ class ChatRepository(
     val conversationChanges: Flow<List<Conversation>>
         get() = database.conversationChanges
 
-    val messagesAdded: Flow<List<Message>>
+    fun messagesChanged(conversation: Conversation): Flow<List<Message>> =
-        get() = database.messagesAdded
+        database.messagesChanged(conversation)
+
+    // Testing harness
+    internal class TestingHarness(private val repository: ChatRepository) {
+        suspend fun fetchConversations(): List<Conversation> {
+            return repository.fetchConversations()
+        }
+
+        suspend fun fetchMessages(conversation: Conversation): List<Message> {
+            return repository.fetchMessages(conversation)
+        }
+    }
+
+    internal fun testingHarness(): TestingHarness = TestingHarness(this)
 
     private data class OutgoingMessageInfo (
         val message: Message,
@@ -41,24 +61,39 @@ class ChatRepository(
         val guid: GUID,
     )
 
+    private val apiInterface = apiClient.getAPIInterface()
     private val outgoingMessageQueue: ArrayBlockingQueue<OutgoingMessageInfo> = ArrayBlockingQueue(16)
     private var outgoingMessageThread: Thread? = null
 
+    private val updateMonitor = UpdateMonitor(apiClient)
+    private var updateWatchJob: Job? = null
+
     suspend fun getVersion(): String {
         return apiInterface.getVersion().string()
     }
 
-    suspend fun fetchConversations(): List<Conversation> {
+    fun beginWatchingForUpdates(scope: CoroutineScope) {
-        return apiInterface.getConversations().bodyOnSuccessOrThrow()
+        updateWatchJob?.cancel()
+        updateWatchJob = CoroutineScope(scope.coroutineContext).launch {
+            launch {
+                updateMonitor.conversationChanged.collect { handleConversationChangedUpdate(it) }
+            }
+            launch {
+                updateMonitor.messageAdded.collect { handleMessageAddedUpdate(it) }
+            }
         }
 
-    suspend fun fetchMessages(conversation: Conversation): List<Message> {
+        updateMonitor.beginMonitoringUpdates()
-        return apiInterface.getMessages(conversation.guid)
-            .bodyOnSuccessOrThrow()
-            .onEach { it.conversation = conversation }
     }
 
-    suspend fun enqueueOutgoingMessage(message: Message, conversation: Conversation): GUID {
+    fun stopWatchingForUpdates() {
+        updateWatchJob?.cancel()
+        updateWatchJob = null
+
+        updateMonitor.stopMonitoringForUpdates()
+    }
+
+    fun enqueueOutgoingMessage(message: Message, conversation: Conversation): GUID {
         val guid = UUID.randomUUID().toString()
 
         Log.d(REPO_LOG, "Enqueuing outgoing message: $message ($guid)")
@@ -76,6 +111,10 @@ class ChatRepository(
         return database.getConversationByGuid(guid).toConversation()
     }
 
+    fun messagesForConversation(conversation: Conversation): List<Message> {
+        return database.fetchMessages(conversation)
+    }
+
     suspend fun synchronize() {
         Log.d(REPO_LOG, "Synchronizing conversations")
 
@@ -84,6 +123,7 @@ class ChatRepository(
         database.writeConversations(conversations)
 
         // Sync top N number of conversations' message content
+        Log.d(REPO_LOG, "Synchronizing messages")
         val sortedConversations = conversations.sortedBy { it.date }
         for (conversation in sortedConversations.take(CONVERSATION_MESSAGE_SYNC_COUNT)) {
             val messages = fetchMessages(conversation)
@@ -97,6 +137,26 @@ class ChatRepository(
 
     // - private
 
+    private suspend fun fetchConversations(): List<Conversation> {
+        return apiInterface.getConversations().bodyOnSuccessOrThrow()
+    }
+
+    private suspend fun fetchMessages(conversation: Conversation): List<Message> {
+        return apiInterface.getMessages(conversation.guid)
+            .bodyOnSuccessOrThrow()
+            .onEach { it.conversation = conversation }
+    }
+
+    private fun handleConversationChangedUpdate(conversation: Conversation) {
+        Log.d(REPO_LOG, "Handling conversation changed update")
+        database.writeConversations(conversations)
+    }
+
+    private fun handleMessageAddedUpdate(message: Message) {
+        Log.d(REPO_LOG, "Handling messages added update")
+        database.writeMessages(listOf(message), message.conversation)
+    }
+
     private fun outgoingMessageQueueMain() {
         Log.d(REPO_LOG, "Outgoing Message Queue Main")
         while (true) {

backend/src/test/java/net/buzzert/kordophone/backend/BackendTests.kt

@@ -2,6 +2,7 @@ package net.buzzert.kordophone.backend
 
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.cancel
+import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.withContext
@@ -22,16 +23,15 @@ import java.util.concurrent.TimeUnit
 class BackendTests {
     private fun liveRepository(host: String): Pair<ChatRepository, RetrofitAPIClient> {
         val client = RetrofitAPIClient(URL(host))
-        val apiInterface = client.getAPIInterface()
         val database = CachedChatDatabase.testDatabase()
-        val repository = ChatRepository(apiInterface, database)
+        val repository = ChatRepository(client, database)
         return Pair(repository, client)
     }
 
     private fun mockRepository(): Pair<ChatRepository, MockServer> {
         val mockServer = MockServer()
         val database = CachedChatDatabase.testDatabase()
-        val repository = ChatRepository(mockServer.getAPIInterface(), database)
+        val repository = ChatRepository(mockServer.getClient(), database)
         return Pair(repository, mockServer)
     }
 
@@ -51,7 +51,7 @@ class BackendTests {
         // Add conversation to mock server
         val inConversation = mockServer.addTestConversations(1).first()
 
-        val conversations = repository.fetchConversations()
+        val conversations = repository.testingHarness().fetchConversations()
         assertEquals(conversations.count(), 1)
 
         val outConversation = conversations.first()
@@ -68,8 +68,8 @@ class BackendTests {
         val inConversation = mockServer.addTestConversations(1).first()
         val inMessage = mockServer.addTestMessages(1, inConversation).first()
 
-        val conversations = repository.fetchConversations()
+        val conversations = repository.testingHarness().fetchConversations()
-        val messages = repository.fetchMessages(conversations.first())
+        val messages = repository.testingHarness().fetchMessages(conversations.first())
         assertEquals(messages.count(), 1)
 
         val outMessage = messages.first()
@@ -143,6 +143,7 @@ class BackendTests {
 
                 // We got it.
                 if (it.isNotEmpty()) {
+                    println("bink")
                     updateLatch.countDown()
                     cancel()
                 }
@@ -179,22 +180,24 @@ class BackendTests {
         repo.synchronize()
 
         // Set up flow watcher, asynchronously
-        var messageAdded: Message? = null
+        var messagesAdded: List<Message>? = null
         val updateLatch = CountDownLatch(1)
         val job = launch {
             println("Watching for messages to be added...")
-            repo.messagesAdded.collect {
+            repo.messagesChanged(conversation).collect {
-                println("Messages added: $it")
+                println("Messages changed: $it")
 
-                messageAdded = it.first()
+                if (it.isNotEmpty()) {
+                    messagesAdded = it
                     updateLatch.countDown()
                     cancel()
                 }
             }
+        }
 
         withContext(Dispatchers.IO) {
             // Add a message
-            val message = mockServer.addTestMessages(1, conversation).first()
+            val messages = mockServer.addTestMessages(10, conversation)
 
             // Sync. This should trigger an update
             println("Synchronizing...")
@@ -207,7 +210,7 @@ class BackendTests {
             assertTrue(updateLatch.await(1, TimeUnit.SECONDS))
 
             // Check what we got back
-            assertEquals(message, messageAdded)
+            assertEquals(messages, messagesAdded)
         }
     }
 
@@ -232,8 +235,6 @@ class BackendTests {
         }
 
         withContext(Dispatchers.IO) {
-            mockAPIClient.startWatchingForUpdates(this)
-
             Thread.sleep(500)
 
             // Add a conversation
@@ -269,8 +270,6 @@ class BackendTests {
         }
 
         withContext(Dispatchers.IO) {
-            mockAPIClient.startWatchingForUpdates(this)
-
             Thread.sleep(500)
 
             // Add a conversation
@@ -287,4 +286,52 @@ class BackendTests {
             assertTrue(updateLatch.await(1, TimeUnit.SECONDS))
         }
     }
+
+    @Test
+    fun testEndToEndMessageUpdates() = runBlocking {
+        val (repo, mockServer) = mockRepository()
+
+        val conversation = mockServer.addTestConversations(1).first()
+
+        // Initial sync
+        repo.synchronize()
+
+        // We're going to generate a couple of messages...
+        val messagesToGenerate = 5
+
+        // Start watching for N updates
+        val updateLatch = CountDownLatch(messagesToGenerate)
+        val monitorJob = launch {
+            repo.messagesChanged(conversation).collect {
+                println("Message changed: $it")
+
+                if (it.isNotEmpty()) {
+                    updateLatch.countDown()
+                }
+
+                if (updateLatch.count == 0L) {
+                    repo.stopWatchingForUpdates()
+                    cancel()
+                }
+            }
+        }
+
+        withContext(Dispatchers.IO) {
+            repo.beginWatchingForUpdates(this)
+
+            Thread.sleep(500)
+
+            // Should trigger an update
+            println("Adding messages")
+            mockServer.addTestMessages(messagesToGenerate, conversation)
+
+            monitorJob.join()
+
+            assertTrue(updateLatch.await(1, TimeUnit.SECONDS))
+
+            // Check num messages
+            val allMessages = repo.messagesForConversation(conversation)
+            assertEquals(messagesToGenerate, allMessages.count())
+        }
+    }
 }

backend/src/test/java/net/buzzert/kordophone/backend/DatabaseTests.kt

@@ -32,15 +32,16 @@ class DatabaseTests {
         val conversation = MockServer.generateConversation()
         db.writeConversations(listOf(conversation))
 
-        val message = MockServer.generateMessage(conversation)
+        var messages = listOf(
-        db.writeMessages(listOf(message), conversation)
+            MockServer.generateMessage(conversation),
+            MockServer.generateMessage(conversation),
+        )
+        db.writeMessages(messages, conversation)
 
         val readMessages = db.fetchMessages(conversation)
-        assertEquals(readMessages.count(), 1)
 
-        val readMessage = readMessages[0]
+        assertEquals(readMessages, messages)
-        assertEquals(readMessage, message)
+        assertEquals(readMessages[0].conversation, conversation)
-        assertEquals(readMessage.conversation, conversation)
 
         db.close()
     }

backend/src/test/java/net/buzzert/kordophone/backend/MockServer.kt

@@ -39,6 +39,8 @@ class MockServer {
     private val messages: MutableMap<String, MutableList<Message>> = mutableMapOf()
     private val _updateFlow: MutableSharedFlow<UpdateItem> = MutableSharedFlow()
 
+    private val client = MockServerClient(this)
+
     companion object {
         fun generateMessage(parentConversation: Conversation): Message {
             return Message(
@@ -64,7 +66,7 @@ class MockServer {
     }
 
     fun getServer(): MockWebServer = MockWebServer()
-    fun getClient(): MockServerClient = MockServerClient(this)
+    fun getClient(): MockServerClient = client
     fun getAPIInterface(): APIInterface = MockServerClient(this).getAPIInterface()
 
     fun addConversation(conversation: Conversation) {
@@ -79,6 +81,11 @@ class MockServer {
         }
     }
 
+    fun updateConversation(conversation: Conversation) {
+        conversations.removeAll { it.guid == conversation.guid }
+        addConversation(conversation)
+    }
+
     fun addMessagesToConversation(conversation: Conversation, messages: List<Message>) {
         val guid = conversation.guid
         this.messages[guid]?.addAll(messages)
@@ -86,11 +93,15 @@ class MockServer {
         conversation.lastMessagePreview = messages.last().text
 
         runBlocking {
-            _updateFlow.emit(UpdateItem(
+            for (message in messages) {
+                _updateFlow.emit(
+                    UpdateItem(
                         sequence = updateMessageSequence++,
                         conversationChanged = conversation,
-                messageAdded = messages.first()
+                        messageAdded = message
-            ))
+                    )
+                )
+            }
         }
     }
 
@@ -160,10 +171,16 @@ class MockServerClient(private val server: MockServer): APIClient, WebSocketList
 
         webServer.enqueue(MockResponse().withWebSocketUpgrade(this))
 
+        if (this.updateWatchJob == null) {
+            CoroutineScope(Job()).launch {
+                startWatchingForUpdates(this)
+            }
+        }
+
         return OkHttpClient().newWebSocket(request, listener)
     }
 
-    fun startWatchingForUpdates(scope: CoroutineScope) {
+    private fun startWatchingForUpdates(scope: CoroutineScope) {
         this.updateWatchJob = scope.launch {
             server.updateFlow.collect {
                 println("Mock WebSocket is sending a message")