Implements UpdateMonitor

backend/src/main/java/net/buzzert/kordophone/backend/model/UpdateItem.kt

@@ -0,0 +1,14 @@
+package net.buzzert.kordophone.backend.model
+
+import com.google.gson.annotations.SerializedName
+
+data class UpdateItem(
+    @SerializedName("messageSequenceNumber")
+    val sequence: Int,
+
+    @SerializedName("conversation")
+    val conversationChanged: Conversation? = null,
+
+    @SerializedName("message")
+    val messageAdded: Message? = null,
+)

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

@@ -1,16 +1,52 @@
 package net.buzzert.kordophone.backend.server
 
+import okhttp3.HttpUrl
+import okhttp3.OkHttpClient
+import okhttp3.Request
+import okhttp3.WebSocket
+import okhttp3.WebSocketListener
 import retrofit2.Retrofit
 import retrofit2.converter.gson.GsonConverterFactory
 import java.net.URL
 
-class APIClient(baseURL: URL) {
+interface APIClient {
+    fun getAPIInterface(): APIInterface
+    fun getWebSocketClient(
+        serverPath: String,
+        authToken: String? = null,
+        listener: WebSocketListener
+    ): WebSocket
+}
+
+class RetrofitAPIClient(private val baseURL: URL): APIClient {
     private val retrofit: Retrofit = Retrofit.Builder()
         .baseUrl(baseURL)
         .addConverterFactory(GsonConverterFactory.create())
         .build()
 
-    fun getClient(): Retrofit {
-        return retrofit
+    override fun getAPIInterface(): APIInterface {
+        return retrofit.create(APIInterface::class.java)
+    }
+
+    override fun getWebSocketClient(serverPath: String, authToken: String?, listener: WebSocketListener): WebSocket {
+        val requestURL = baseURL.authenticatedWebSocketURL(serverPath, authToken)
+        val request = Request.Builder()
+            .url(requestURL)
+            .build()
+
+        return OkHttpClient().newWebSocket(request, listener)
     }
 }
+
+fun URL.authenticatedWebSocketURL(serverPath: String, authToken: String? = null): URL {
+    val baseURI = HttpUrl.parse(this.toString())!!
+    val requestURL = baseURI.newBuilder()
+        .host(baseURI.host())
+        .addEncodedPathSegments(serverPath)
+
+    if (authToken != null) {
+        requestURL.addQueryParameter("token", authToken)
+    }
+
+    return URL(requestURL.build().toString())
+}

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

@@ -0,0 +1,91 @@
+package net.buzzert.kordophone.backend.server
+
+import android.util.Log
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.runBlocking
+import net.buzzert.kordophone.backend.model.Conversation
+import net.buzzert.kordophone.backend.model.Message
+import net.buzzert.kordophone.backend.model.UpdateItem
+import okhttp3.Response
+import okhttp3.WebSocket
+import okhttp3.WebSocketListener
+import okio.ByteString
+import retrofit2.converter.gson.GsonConverterFactory
+import java.lang.reflect.Type
+
+const val UPMON_LOG: String = "ChatRepository"
+
+class UpdateMonitor(private val client: APIClient) : WebSocketListener() {
+    // Flow for getting conversation changed notifications
+    val conversationChanged: Flow<Conversation>
+        get() = _conversationChanged
+
+    // Flow for messages added notifications
+    val messageAdded: Flow<Message>
+        get() = _messageAdded
+
+    private val gson: Gson = Gson()
+    private val updateItemsType: Type = object : TypeToken<ArrayList<UpdateItem>>() {}.type
+    private var webSocket: WebSocket? = null
+
+    private val _conversationChanged: MutableSharedFlow<Conversation> = MutableSharedFlow()
+    private val _messageAdded: MutableSharedFlow<Message> = MutableSharedFlow()
+
+
+    fun beginMonitoringUpdates() {
+        Log.d(UPMON_LOG, "Opening websocket connection")
+        this.webSocket = client.getWebSocketClient("/updates", null, this)
+    }
+
+    fun stopMonitoringForUpdates() {
+        this.webSocket?.close(1000, "Closing on program request.")
+    }
+
+    private fun processEncodedSocketMessage(message: String) = runBlocking {
+        val reader = message.reader()
+        val jsonReader = gson.newJsonReader(reader)
+
+        val updateItems: List<UpdateItem> = gson.fromJson(message, updateItemsType)
+        for (updateItem: UpdateItem in updateItems) {
+            if (updateItem.conversationChanged != null) {
+                _conversationChanged.emit(updateItem.conversationChanged)
+            }
+
+            if (updateItem.messageAdded != null) {
+                _messageAdded.emit(updateItem.messageAdded)
+            }
+        }
+    }
+
+    // <WebSocketListener>
+
+    override fun onOpen(webSocket: WebSocket, response: Response) {
+        super.onOpen(webSocket, response)
+        Log.d(UPMON_LOG, "Update monitor websocket open")
+    }
+
+    override fun onClosed(webSocket: WebSocket, code: Int, reason: String) {
+        super.onClosed(webSocket, code, reason)
+        Log.d(UPMON_LOG, "Update monitor socket closed")
+    }
+
+    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()}")
+    }
+
+    override fun onMessage(webSocket: WebSocket, text: String) {
+        super.onMessage(webSocket, text)
+        Log.d(UPMON_LOG, "Update monitor websocket received text message")
+        processEncodedSocketMessage(text)
+    }
+
+    override fun onMessage(webSocket: WebSocket, bytes: ByteString) {
+        super.onMessage(webSocket, bytes)
+        Log.d(UPMON_LOG, "Update monitor websocket received bytes message")
+        processEncodedSocketMessage(bytes.utf8())
+    }
+}

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

@@ -9,6 +9,8 @@ import net.buzzert.kordophone.backend.db.CachedChatDatabase
 import net.buzzert.kordophone.backend.server.APIClient
 import net.buzzert.kordophone.backend.server.APIInterface
 import net.buzzert.kordophone.backend.server.ChatRepository
+import net.buzzert.kordophone.backend.server.RetrofitAPIClient
+import net.buzzert.kordophone.backend.server.UpdateMonitor
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertTrue
 import org.junit.Test
@@ -17,17 +19,18 @@ import java.util.concurrent.CountDownLatch
 import java.util.concurrent.TimeUnit
 
 class BackendTests {
-    private fun liveRepository(host: String): ChatRepository {
-        val client = APIClient(URL(host))
-        val apiInterface = client.getClient().create(APIInterface::class.java)
+    private fun liveRepository(host: String): Pair<ChatRepository, RetrofitAPIClient> {
+        val client = RetrofitAPIClient(URL(host))
+        val apiInterface = client.getAPIInterface()
         val database = CachedChatDatabase.testDatabase()
-        return ChatRepository(apiInterface, database)
+        val repository = ChatRepository(apiInterface, database)
+        return Pair(repository, client)
     }
 
     private fun mockRepository(): Pair<ChatRepository, MockServer> {
         val mockServer = MockServer()
         val database = CachedChatDatabase.testDatabase()
-        val repository = ChatRepository(mockServer, database)
+        val repository = ChatRepository(mockServer.getAPIInterface(), database)
         return Pair(repository, mockServer)
     }
 
@@ -161,4 +164,41 @@ class BackendTests {
             assertTrue(updateLatch.await(1, TimeUnit.SECONDS))
         }
     }
+
+    @Test
+    fun testUpdateMonitor() = runBlocking {
+        val mockServer = MockServer()
+        val mockAPIClient = mockServer.getClient()
+        val updateMonitor = UpdateMonitor(mockAPIClient)
+
+        // Set up flow watcher, asynchronously
+        val updateLatch = CountDownLatch(1)
+        val job = launch {
+            updateMonitor.beginMonitoringUpdates()
+            updateMonitor.conversationChanged.collect {
+                println("Got conversation changed: $it")
+                updateLatch.countDown()
+
+                updateMonitor.stopMonitoringForUpdates()
+                mockAPIClient.stopWatchingForUpdates()
+                cancel()
+            }
+        }
+
+        withContext(Dispatchers.IO) {
+            mockAPIClient.startWatchingForUpdates(this)
+
+            Thread.sleep(500)
+
+            // Add a conversation
+            println("Adding conversation")
+            mockServer.addTestConversations(1)
+
+            // Wait for the coroutine that is collecting the flow to finish
+            job.join()
+
+            // Ensure the updates have been processed before proceeding
+            assertTrue(updateLatch.await(1, TimeUnit.SECONDS))
+        }
+    }
 }

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

@@ -1,20 +1,47 @@
 package net.buzzert.kordophone.backend
 
+import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.cancelAndJoin
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableSharedFlow
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.runBlocking
 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 net.buzzert.kordophone.backend.server.APIClient
 import net.buzzert.kordophone.backend.server.APIInterface
 import net.buzzert.kordophone.backend.server.SendMessageRequest
+import net.buzzert.kordophone.backend.server.authenticatedWebSocketURL
+import okhttp3.HttpUrl
 import okhttp3.MediaType
 import okhttp3.MediaType.Companion.toMediaType
+import okhttp3.OkHttpClient
+import okhttp3.Request
 import okhttp3.ResponseBody
+import okhttp3.ResponseBody.Companion.toResponseBody
+import okhttp3.WebSocket
+import okhttp3.WebSocketListener
+import okhttp3.mockwebserver.MockResponse
+import okhttp3.mockwebserver.MockWebServer
 import retrofit2.Response
+import java.net.URL
 import java.util.Date
 import java.util.UUID
 
-class MockServer: APIInterface {
+class MockServer {
     val version = "Kordophone-2.0"
     val conversations: MutableList<Conversation> = mutableListOf()
-    val messages: MutableMap<String, MutableList<Message>> = mutableMapOf()
+    val updateFlow: Flow<UpdateItem> get() = _updateFlow
+    var updateMessageSequence: Int = 0
+
+    private val messages: MutableMap<String, MutableList<Message>> = mutableMapOf()
+    private val _updateFlow: MutableSharedFlow<UpdateItem> = MutableSharedFlow()
 
     companion object {
         fun generateMessage(): Message {
@@ -40,35 +67,19 @@ class MockServer: APIInterface {
         }
     }
 
-    override suspend fun getVersion(): ResponseBody {
-        return ResponseBody.create("text/plain".toMediaType(), version)
-    }
-
-    override suspend fun getConversations(): Response<List<Conversation>> {
-        return Response.success(conversations)
-    }
-
-    override suspend fun getMessages(conversationGUID: String): Response<List<Message>> {
-        return Response.success(messages[conversationGUID])
-    }
-
-    override suspend fun sendMessage(request: SendMessageRequest): Response<Void> {
-        val message = Message(
-            text = request.body,
-            date = Date(),
-            guid = UUID.randomUUID().toString(),
-            sender = null, // me
-        )
-
-        messages[request.conversationGUID]?.add(message) ?: run {
-            messages[request.conversationGUID] = mutableListOf(message)
-        }
-
-        return Response.success(null)
-    }
+    fun getServer(): MockWebServer = MockWebServer()
+    fun getClient(): MockServerClient = MockServerClient(this)
+    fun getAPIInterface(): APIInterface = MockServerClient(this).getAPIInterface()
 
     fun addConversation(conversation: Conversation) {
         conversations.add(conversation)
+
+        runBlocking {
+            _updateFlow.emit(UpdateItem(
+                sequence = updateMessageSequence++,
+                conversationChanged = conversation
+            ))
+        }
     }
 
     fun addMessagesToConversation(conversation: Conversation, messages: List<Message>) {
@@ -76,6 +87,14 @@ class MockServer: APIInterface {
         this.messages[guid]?.addAll(messages) ?: run {
             this.messages[guid] = messages.toMutableList()
         }
+
+        runBlocking {
+            _updateFlow.emit(UpdateItem(
+                sequence = updateMessageSequence++,
+                conversationChanged = conversation,
+                messageAdded = messages.first()
+            ))
+        }
     }
 
     fun addTestConversations(count: Int): List<Conversation> {
@@ -99,4 +118,105 @@ class MockServer: APIInterface {
         addMessagesToConversation(conversation, testMessages)
         return testMessages
     }
+
+    internal fun getMessagesForConversationGUID(guid: GUID): List<Message>? {
+        return messages[guid]?.toList()
+    }
+
+    internal fun sendMessage(body: String, toConversationGUID: GUID) {
+        val message = Message(
+            text = body,
+            date = Date(),
+            guid = UUID.randomUUID().toString(),
+            sender = null, // me
+        )
+
+        val conversation = conversations.first { it.guid == toConversationGUID }
+        addMessagesToConversation(conversation, listOf(message))
+    }
+}
+
+class MockServerClient(private val server: MockServer): APIClient, WebSocketListener() {
+    private var updateWebSocket: WebSocket? = null
+    private var updateWatchJob: Job? = null
+    private val gson: Gson = Gson()
+
+    override fun getAPIInterface(): APIInterface {
+        return MockServerInterface(server)
+    }
+
+    override fun getWebSocketClient(
+        serverPath: String,
+        authToken: String?,
+        listener: WebSocketListener
+    ): WebSocket {
+        val webServer = server.getServer()
+
+        val baseHTTPURL: HttpUrl = webServer.url("/")
+        val baseURL = baseHTTPURL.toUrl()
+        val requestURL = baseURL.authenticatedWebSocketURL(serverPath, authToken)
+        val request = Request.Builder()
+            .url(requestURL)
+            .build()
+
+        webServer.enqueue(MockResponse().withWebSocketUpgrade(this))
+
+        return OkHttpClient().newWebSocket(request, listener)
+    }
+
+    fun startWatchingForUpdates(scope: CoroutineScope) {
+        this.updateWatchJob = scope.launch {
+            server.updateFlow.collect {
+                println("Mock WebSocket is sending a message")
+
+                // Encode to JSON and send to websocket
+                val updateItems = listOf(it)
+                val encodedUpdateItem = gson.toJson(updateItems)
+                updateWebSocket?.send(encodedUpdateItem)
+            }
+        }
+    }
+
+    fun stopWatchingForUpdates() = runBlocking {
+        updateWatchJob?.cancelAndJoin()
+    }
+
+    override fun onOpen(webSocket: WebSocket, response: okhttp3.Response) {
+        super.onOpen(webSocket, response)
+
+        println("Mock WebSocket opened.")
+        this.updateWebSocket = webSocket
+    }
+
+    override fun onClosed(webSocket: WebSocket, code: Int, reason: String) {
+        super.onClosed(webSocket, code, reason)
+
+        println("Mock WebSocket closed.")
+        this.updateWebSocket = null
+    }
+}
+
+class MockServerInterface(private val server: MockServer): APIInterface {
+    override suspend fun getVersion(): ResponseBody {
+        return server.version.toResponseBody("text/plain".toMediaType())
+    }
+
+    override suspend fun getConversations(): Response<List<Conversation>> {
+        return Response.success(server.conversations)
+    }
+
+    override suspend fun getMessages(conversationGUID: String): Response<List<Message>> {
+        val messages = server.getMessagesForConversationGUID(conversationGUID)
+
+        return if (messages != null) {
+            Response.success(messages)
+        } else {
+            Response.error(500, "GUID not found".toResponseBody())
+        }
+    }
+
+    override suspend fun sendMessage(request: SendMessageRequest): Response<Void> {
+        server.sendMessage(request.body, request.conversationGUID)
+        return Response.success(null)
+    }
 }