Fix loading same page always on chat

app/src/main/java/chat/rocket/android/chatroom/presentation/ChatRoomPresenter.kt

@@ -6,8 +6,6 @@ import chat.rocket.android.chatroom.adapter.AutoCompleteType
 import chat.rocket.android.chatroom.adapter.PEOPLE
 import chat.rocket.android.chatroom.adapter.ROOMS
 import chat.rocket.android.chatroom.domain.UriInteractor
-import chat.rocket.android.chatroom.viewmodel.BaseViewModel
-import chat.rocket.android.chatroom.viewmodel.MessageViewModel
 import chat.rocket.android.chatroom.viewmodel.ViewModelMapper
 import chat.rocket.android.chatroom.viewmodel.suggestion.ChatRoomSuggestionViewModel
 import chat.rocket.android.chatroom.viewmodel.suggestion.CommandSuggestionViewModel
@@ -75,19 +73,17 @@ class ChatRoomPresenter @Inject constructor(private val view: ChatRoomView,
         launchUI(strategy) {
             view.showLoading()
             try {
-                val localMessages = messagesRepository.getByRoomId(chatRoomId)
-                val oldMessages = mapper.map(localMessages)
-                view.showMessages(oldMessages)
-                if (oldMessages.isEmpty()) {
-                    val messages =
-                        retryIO(description = "messages chatRoom: $chatRoomId, type: $chatRoomType, offset: $offset") {
-                            client.messages(chatRoomId, roomTypeOf(chatRoomType), offset, 30).result
-                        }
-                    messagesRepository.saveAll(messages)
-                    val allMessages = mapper.map(messages)
-                    view.showMessages(allMessages)
+                if (offset == 0L) {
+                    val localMessages = messagesRepository.getByRoomId(chatRoomId)
+                    val oldMessages = mapper.map(localMessages)
+                    if (oldMessages.isNotEmpty()) {
+                        view.showMessages(oldMessages)
+                        loadMissingMessages()
+                    } else {
+                        loadAndShowMessages(chatRoomId, chatRoomType, offset)
+                    }
                 } else {
-                    loadMissingMessages()
+                    loadAndShowMessages(chatRoomId, chatRoomType, offset)
                 }
 
                 // TODO: For now we are marking the room as read if we can get the messages (I mean, no exception occurs)
@@ -112,6 +108,16 @@ class ChatRoomPresenter @Inject constructor(private val view: ChatRoomView,
         }
     }
 
+    private suspend fun loadAndShowMessages(chatRoomId: String, chatRoomType: String, offset: Long = 0) {
+        val messages =
+            retryIO(description = "messages chatRoom: $chatRoomId, type: $chatRoomType, offset: $offset") {
+                client.messages(chatRoomId, roomTypeOf(chatRoomType), offset, 30).result
+            }
+        messagesRepository.saveAll(messages)
+        val allMessages = mapper.map(messages)
+        view.showMessages(allMessages)
+    }
+
     fun sendMessage(chatRoomId: String, text: String, messageId: String?) {
         launchUI(strategy) {
             try {