backend: don't fetch messages with conversations.

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

@@ -62,12 +62,10 @@ class CachedChatDatabase (private val realmConfig: RealmConfiguration) {
 
     // Flow for watching for message changes for a given conversation
     fun messagesChanged(conversation: ModelConversation): Flow<List<ModelMessage>> {
-        return realm.query(Conversation::class, "guid == $0", conversation.guid)
+        return realm.query(Message::class, "conversationGUID == $0", conversation.guid)
             .find()
-            .first()
-            .messages
             .asFlow()
-            .map { it.set.map { it.toMessage(conversation) } }
+            .map { it.list.map { it.toMessage(conversation) } }
     }
 
     fun updateConversations(incomingConversations: List<ModelConversation>) = realm.writeBlocking {
@@ -98,6 +96,7 @@ class CachedChatDatabase (private val realmConfig: RealmConfiguration) {
                     participants = conversation.participants
                     date = conversation.date
                     unreadCount = conversation.unreadCount
+                    lastMessagePreview = conversation.lastMessagePreview
                 }
             } catch (e: NoSuchElementException) {
                 // Conversation does not exist. Copy it to the realm.
@@ -124,17 +123,21 @@ class CachedChatDatabase (private val realmConfig: RealmConfiguration) {
     fun writeMessages(messages: List<ModelMessage>, conversation: ModelConversation, outgoing: Boolean = false) {
         val dbConversation = getManagedConversationByGuid(conversation.guid)
         realm.writeBlocking {
-            val dbMessages = messages
+            messages
                 .map { it.toDatabaseMessage(outgoing = outgoing) }
                 .map { copyToRealm(it, updatePolicy = UpdatePolicy.ALL) }
 
-            findLatest(dbConversation)?.messages?.addAll(dbMessages)
+            findLatest(dbConversation)?.let {
+                it.lastMessagePreview = messages.last().displayText
+                it.date = messages.last().date.toInstant().toRealmInstant()
+            }
         }
     }
 
     fun fetchMessages(conversation: ModelConversation): List<ModelMessage> {
-        val dbConversation = getConversationByGuid(conversation.guid)
-        return dbConversation.messages.map { it.toMessage(dbConversation.toConversation()) }
+        return realm.query(Message::class, "conversationGUID == $0", conversation.guid)
+            .find()
+            .map { it.toMessage(conversation) }
     }
 
     fun close() {

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

@@ -25,7 +25,6 @@ open class Conversation(
     var unreadCount: Int,
 
     var lastMessagePreview: String?,
-    var messages: RealmSet<Message>,
 ): RealmObject
 {
     constructor() : this(
@@ -36,8 +35,6 @@ open class Conversation(
         date = RealmInstant.now(),
         unreadCount = 0,
         lastMessagePreview = null,
-
-        messages = realmSetOf<Message>()
     )
 
     fun toConversation(): ModelConversation {
@@ -51,19 +48,9 @@ open class Conversation(
             lastMessage = null,
         )
 
-        if (messages.isNotEmpty()) {
-            val lastMessage = sortedMessages().last()
-            conversation.lastMessage = lastMessage.toMessage(conversation)
-            conversation.lastMessagePreview = lastMessage.text
-        }
-
         return conversation
     }
 
-    private fun sortedMessages(): List<Message> {
-        return messages.sortedBy { it.date }
-    }
-
     override fun equals(other: Any?): Boolean {
         if (other == null || javaClass != other.javaClass) return false