Try only synchronizing messages after last GUID

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

@@ -97,6 +97,7 @@ class CachedChatDatabase (private val realmConfig: RealmConfiguration) {
                     date = conversation.date
                     unreadCount = conversation.unreadCount
                     lastMessagePreview = conversation.lastMessagePreview
+                    lastMessageGUID = conversation.lastMessageGUID
                 }
             } catch (e: NoSuchElementException) {
                 // Conversation does not exist. Copy it to the realm.
@@ -121,6 +122,10 @@ class CachedChatDatabase (private val realmConfig: RealmConfiguration) {
     }
 
     fun writeMessages(messages: List<ModelMessage>, conversation: ModelConversation, outgoing: Boolean = false) {
+        if (messages.isEmpty()) {
+            return
+        }
+
         val dbConversation = getManagedConversationByGuid(conversation.guid)
         realm.writeBlocking {
             messages
@@ -128,8 +133,17 @@ class CachedChatDatabase (private val realmConfig: RealmConfiguration) {
                 .map { copyToRealm(it, updatePolicy = UpdatePolicy.ALL) }
 
             findLatest(dbConversation)?.let {
-                it.lastMessagePreview = messages.last().displayText
+                val lastMessage = messages.maxByOrNull { it.date }!!
-                it.date = messages.last().date.toInstant().toRealmInstant()
+
+                val lastMessageDate = lastMessage.date.toInstant().toRealmInstant()
+                if (lastMessageDate > it.date) {
+                    it.lastMessageGUID = lastMessage.guid
+                    it.lastMessagePreview = lastMessage.displayText
+
+                    // This will cause sort order to change. I think this ends
+                    // up getting updated whenever we get conversation changes anyway.
+                    // it.date = lastMessageDate
+                }
             }
         }
     }

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

@@ -1,17 +1,13 @@
 package net.buzzert.kordophone.backend.db.model
 
-import io.realm.kotlin.Realm
 import io.realm.kotlin.ext.realmListOf
-import io.realm.kotlin.ext.realmSetOf
 import io.realm.kotlin.ext.toRealmList
 import io.realm.kotlin.types.RealmInstant
 import io.realm.kotlin.types.RealmList
 import io.realm.kotlin.types.RealmObject
-import io.realm.kotlin.types.RealmSet
 import io.realm.kotlin.types.annotations.PrimaryKey
 import net.buzzert.kordophone.backend.model.GUID
 import org.mongodb.kbson.ObjectId
-import java.time.Instant
 import net.buzzert.kordophone.backend.model.Conversation as ModelConversation
 import java.util.Date
 
@@ -24,6 +20,7 @@ open class Conversation(
     var date: RealmInstant,
     var unreadCount: Int,
 
+    var lastMessageGUID: String?,
     var lastMessagePreview: String?,
 ): RealmObject
 {
@@ -35,10 +32,11 @@ open class Conversation(
         date = RealmInstant.now(),
         unreadCount = 0,
         lastMessagePreview = null,
+        lastMessageGUID = null,
     )
 
     fun toConversation(): ModelConversation {
-        val conversation = ModelConversation(
+        return ModelConversation(
             displayName = displayName,
             participants = participants.toList(),
             date = Date.from(date.toInstant()),
@@ -46,9 +44,8 @@ open class Conversation(
             guid = guid,
             lastMessagePreview = lastMessagePreview,
             lastMessage = null,
+            lastFetchedMessageGUID = lastMessageGUID
         )
-
-        return conversation
     }
 
     override fun equals(other: Any?): Boolean {
@@ -57,6 +54,10 @@ open class Conversation(
         val o = other as Conversation
         return guid == o.guid
     }
+
+    override fun hashCode(): Int {
+        return guid.hashCode()
+    }
 }
 
 fun ModelConversation.toDatabaseConversation(): Conversation {
@@ -67,6 +68,7 @@ fun ModelConversation.toDatabaseConversation(): Conversation {
         date = from.date.toInstant().toRealmInstant()
         unreadCount = from.unreadCount
         lastMessagePreview = from.lastMessagePreview
+        lastMessageGUID = from.lastFetchedMessageGUID
         guid = from.guid
     }
 }

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

@@ -27,6 +27,8 @@ data class Conversation(
 
     @SerializedName("lastMessage")
     var lastMessage: Message?,
+
+    var lastFetchedMessageGUID: String?,
 ) {
     companion object {
         fun generate(): Conversation {
@@ -38,6 +40,7 @@ data class Conversation(
                 unreadCount =  0,
                 lastMessagePreview = null,
                 lastMessage = null,
+                lastFetchedMessageGUID = null,
             )
         }
     }
@@ -59,7 +62,7 @@ data class Conversation(
             participants == o.participants &&
             displayName == o.displayName &&
             unreadCount == o.unreadCount &&
-            lastMessagePreview == o.lastMessagePreview
+            lastFetchedMessageGUID == o.lastFetchedMessageGUID
         )
     }
 
@@ -69,8 +72,8 @@ data class Conversation(
         result = 31 * result + participants.hashCode()
         result = 31 * result + (displayName?.hashCode() ?: 0)
         result = 31 * result + unreadCount
-        result = 31 * result + (lastMessagePreview?.hashCode() ?: 0)
         result = 31 * result + (lastMessage?.hashCode() ?: 0)
+        result = 31 * result + (lastFetchedMessageGUID?.hashCode() ?: 0)
         return result
     }
 }

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

@@ -182,9 +182,7 @@ class ChatRepository(
     }
 
     suspend fun synchronizeConversation(conversation: Conversation, limit: Int = 15) = withErrorChannelHandling {
-        // TODO: Should only fetch messages after the last GUID we know about.
+        val messages = fetchMessages(conversation, limit = limit, afterGUID = conversation.lastFetchedMessageGUID)
-        // But keep in mind that outgoing message GUIDs are fake...
-        val messages = fetchMessages(conversation, limit = limit)
         database.writeMessages(messages, conversation)
     }
 
@@ -233,10 +231,10 @@ class ChatRepository(
     private suspend fun fetchMessages(
         conversation: Conversation,
         limit: Int? = null,
-        before: Message? = null,
+        beforeGUID: String? = null,
-        after: Message? = null,
+        afterGUID: String? = null,
     ): List<Message> {
-        return apiInterface.getMessages(conversation.guid, limit, before?.guid, after?.guid)
+        return apiInterface.getMessages(conversation.guid, limit, beforeGUID, afterGUID)
             .bodyOnSuccessOrThrow()
             .onEach { it.conversation = conversation }
     }

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

@@ -9,6 +9,7 @@ import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.withContext
 import net.buzzert.kordophone.backend.db.CachedChatDatabase
 import net.buzzert.kordophone.backend.model.Message
+import net.buzzert.kordophone.backend.model.OutgoingMessage
 import net.buzzert.kordophone.backend.server.APIClient
 import net.buzzert.kordophone.backend.server.APIInterface
 import net.buzzert.kordophone.backend.server.Authentication
@@ -85,13 +86,18 @@ class BackendTests {
         val (repository, mockServer) = mockRepository()
 
         val conversation = mockServer.addTestConversations(1).first()
-        val outgoingMessage = MockServer.generateMessage(conversation)
+        val generatedMessage = MockServer.generateMessage(conversation)
+        val outgoingMessage = OutgoingMessage(
+            body = generatedMessage.text,
+            conversation = conversation,
+            attachmentUris = setOf(),
+            attachmentDataSource = { null },
+        )
 
-        val guid = repository.enqueueOutgoingMessage(outgoingMessage, conversation)
+        repository.enqueueOutgoingMessage(outgoingMessage)
 
         val event = repository.messageDeliveredChannel.first()
-        assertEquals(event.requestGuid, guid)
+        assertEquals(event.message.text, outgoingMessage.body)
-        assertEquals(event.message.text, outgoingMessage.text)
 
         repository.close()
     }

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

@@ -18,18 +18,19 @@ import net.buzzert.kordophone.backend.server.AuthenticationRequest
 import net.buzzert.kordophone.backend.server.AuthenticationResponse
 import net.buzzert.kordophone.backend.server.SendMessageRequest
 import net.buzzert.kordophone.backend.server.SendMessageResponse
+import net.buzzert.kordophone.backend.server.UploadAttachmentResponse
 import net.buzzert.kordophone.backend.server.authenticatedWebSocketURL
 import okhttp3.HttpUrl
 import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.OkHttpClient
 import okhttp3.Request
+import okhttp3.RequestBody
 import okhttp3.ResponseBody
 import okhttp3.ResponseBody.Companion.toResponseBody
 import okhttp3.WebSocket
 import okhttp3.WebSocketListener
 import okhttp3.mockwebserver.MockResponse
 import okhttp3.mockwebserver.MockWebServer
-import retrofit2.Call
 import retrofit2.Response
 import java.util.Date
 import java.util.UUID
@@ -66,7 +67,8 @@ class MockServer {
                 unreadCount = 0,
                 lastMessagePreview = null,
                 lastMessage = null,
-                guid = UUID.randomUUID().toString()
+                guid = UUID.randomUUID().toString(),
+                lastFetchedMessageGUID = null,
             )
         }
     }
@@ -166,6 +168,8 @@ class MockServerClient(private val server: MockServer): APIClient, WebSocketList
     private var updateWatchJob: Job? = null
     private val gson: Gson = Gson()
 
+    override val isConfigured: Boolean = true
+
     override fun getAPIInterface(): APIInterface {
         return MockServerInterface(server)
     }
@@ -268,6 +272,13 @@ class MockServerInterface(private val server: MockServer): APIInterface {
         TODO("Not yet implemented")
     }
 
+    override suspend fun uploadAttachment(
+        filename: String,
+        body: RequestBody
+    ): Response<UploadAttachmentResponse> {
+        TODO("Not yet implemented")
+    }
+
     override suspend fun authenticate(request: AuthenticationRequest): Response<AuthenticationResponse> {
         // Anything goes!
         val response = AuthenticationResponse(