use sticky header (WIP, experimental, to fix: reverse order issues)

Signed-off-by: Marcel Hibbe <dev@mhibbe.de>

Author: mahibi

app/src/main/java/com/nextcloud/talk/chat/ChatActivity.kt

@@ -3434,7 +3434,7 @@ class ChatActivity :
                 withUrl = urlForChatting,
                 withCredentials = credentials!!,
                 withMessageLimit = MESSAGE_PULL_LIMIT,
-                roomToken = currentConversation!!.token
+                roomToken = roomToken
             )
         }
     }

app/src/main/java/com/nextcloud/talk/chat/data/ChatMessageRepository.kt

@@ -157,4 +157,6 @@ interface ChatMessageRepository : LifecycleAwareManager {
     suspend fun onSignalingChatMessageReceived(chatMessage: ChatMessageJson)
 
     fun observeMessages(internalConversationId: String): Flow<List<ChatMessageEntity>>
+
+    fun observeMessagesForChatKit(internalConversationId: String): Flow<List<ChatMessageEntity>>
 }

app/src/main/java/com/nextcloud/talk/chat/data/network/OfflineFirstChatRepository.kt

@@ -1132,6 +1132,23 @@ class OfflineFirstChatRepository @Inject constructor(
                 }
             }
 
+    override fun observeMessagesForChatKit(internalConversationId: String): Flow<List<ChatMessageEntity>> =
+        chatBlocksDao
+            .getLatestChatBlock(internalConversationId, threadId)
+            .distinctUntilChanged()
+            .flatMapLatest { latestBlock ->
+
+                if (latestBlock == null) {
+                    flowOf(emptyList())
+                } else {
+                    chatDao.getMessagesNewerThanForChatKit(
+                        internalConversationId = internalConversationId,
+                        threadId = threadId,
+                        oldestMessageId = latestBlock.oldestMessageId
+                    )
+                }
+            }
+
     @Suppress("LongParameterList")
     override suspend fun sendScheduledChatMessage(
         credentials: String,

app/src/main/java/com/nextcloud/talk/chat/viewmodels/ChatViewModel.kt

@@ -82,6 +82,7 @@ import java.time.Instant
 import java.time.LocalDate
 import java.time.ZoneId
 import javax.inject.Inject
+import kotlin.collections.asReversed
 
 @Suppress("TooManyFunctions", "LongParameterList")
 class ChatViewModel @AssistedInject constructor(
@@ -354,15 +355,15 @@ class ChatViewModel @AssistedInject constructor(
             .map { messages ->
                 buildList<ChatItem> {
                     var lastDate: LocalDate? = null
-                    messages.asReversed().forEach { msg ->
+                    messages.forEach { msg ->
                         val date = msg.dateKey()
                         if (date != lastDate) {
                             add(ChatItem.DateHeaderItem(date))
                             lastDate = date
                         }
                         add(ChatItem.MessageItem(msg))
                     }
-                }.asReversed()
+                }
             }
             .stateIn(
                 scope = viewModelScope,
@@ -375,7 +376,7 @@ class ChatViewModel @AssistedInject constructor(
         internalConversationId
             .filterNotNull()
             .flatMapLatest { conversationId ->
-                chatRepository.observeMessages(conversationId)
+                chatRepository.observeMessagesForChatKit(conversationId)
             }
             .map { entities -> entities.map(ChatMessageEntity::asModel) }
             .onEach { messages ->
@@ -1326,6 +1327,7 @@ class ChatViewModel @AssistedInject constructor(
 
     sealed interface ChatItem {
         fun messageOrNull(): ChatMessage? = (this as? MessageItem)?.message
+        fun dateOrNull(): LocalDate? = (this as? DateHeaderItem)?.date
 
         fun stableKey(): Any =
             when (this) {

app/src/main/java/com/nextcloud/talk/data/database/dao/ChatMessagesDao.kt

@@ -36,7 +36,7 @@ interface ChatMessagesDao {
       AND isTemporary = 0
       AND (:threadId IS NULL OR threadId = :threadId)
       AND id > :oldestMessageId
-    ORDER BY timestamp DESC, id DESC
+    ORDER BY timestamp ASC, id ASC
     """
     )
     fun getMessagesNewerThan(
@@ -45,6 +45,23 @@ interface ChatMessagesDao {
         oldestMessageId: Long
     ): Flow<List<ChatMessageEntity>>
 
+    @Query(
+        """
+    SELECT *
+    FROM ChatMessages
+    WHERE internalConversationId = :internalConversationId
+      AND isTemporary = 0
+      AND (:threadId IS NULL OR threadId = :threadId)
+      AND id > :oldestMessageId
+    ORDER BY timestamp DESC, id DESC
+    """
+    )
+    fun getMessagesNewerThanForChatKit(
+        internalConversationId: String,
+        threadId: Long?,
+        oldestMessageId: Long
+    ): Flow<List<ChatMessageEntity>>
+
     @Query(
         """
         SELECT *

app/src/main/java/com/nextcloud/talk/ui/chat/ChatView.kt

@@ -35,6 +35,8 @@ import com.nextcloud.talk.R
 import com.nextcloud.talk.chat.UnreadMessagesPopup
 import com.nextcloud.talk.chat.data.model.ChatMessage
 import com.nextcloud.talk.chat.viewmodels.ChatViewModel
+import com.nextcloud.talk.chat.viewmodels.ChatViewModel.ChatItem.DateHeaderItem
+import com.nextcloud.talk.chat.viewmodels.ChatViewModel.ChatItem.MessageItem
 import com.nextcloud.talk.data.user.model.User
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
@@ -128,11 +130,53 @@ fun GetNewChatView(
         LazyColumn(
             state = listState,
             verticalArrangement = Arrangement.spacedBy(8.dp),
-            reverseLayout = true,
+            reverseLayout = false,
             modifier = Modifier
                 .padding(16.dp)
                 .fillMaxSize()
         ) {
+            stickyHeader {
+                if (chatItems.isEmpty()) {
+                    Column(
+                        verticalArrangement = Arrangement.Center,
+                        horizontalAlignment = Alignment.CenterHorizontally,
+                        modifier = Modifier.fillMaxSize()
+                    ) {
+                        ShimmerGroup()
+                    }
+                } else {
+                    val item = chatItems[listState.firstVisibleItemIndex]
+                    val dateString = when (item) {
+                        is MessageItem -> formatTime(item.message.timestamp * LONG_1000)
+                        is DateHeaderItem -> formatTime(item.date)
+                    }
+                    val color = colorScheme.onSurfaceVariant
+                    val backgroundColor =
+                        LocalResources.current.getColor(R.color.bg_message_list_incoming_bubble, null)
+                    Row(
+                        horizontalArrangement = Arrangement.Absolute.Center,
+                        verticalAlignment = Alignment.CenterVertically
+                    ) {
+                        Spacer(modifier = Modifier.weight(1f))
+                        Text(
+                            dateString,
+                            fontSize = AUTHOR_TEXT_SIZE,
+                            color = color,
+                            modifier = Modifier
+                                .padding(8.dp)
+                                .shadow(
+                                    16.dp,
+                                    spotColor = colorScheme.primary,
+                                    ambientColor = colorScheme.primary
+                                )
+                                .background(color = Color(backgroundColor), shape = RoundedCornerShape(8.dp))
+                                .padding(8.dp)
+                        )
+                        Spacer(modifier = Modifier.weight(1f))
+                    }
+                }
+            }
+
             items(
                 displayedChatItems,
                 key = {
@@ -364,8 +408,17 @@ private fun ChatMessage.shouldFilter(): Boolean =
 fun formatTime(timestampMillis: Long): String {
     val instant = Instant.ofEpochMilli(timestampMillis)
     val dateTime = instant.atZone(ZoneId.systemDefault()).toLocalDate()
+    return formatTime(dateTime)
+}
+
+fun formatTime(localDate: LocalDate): String {
     val formatter = DateTimeFormatter.ofPattern("MMM dd, yyyy")
-    return dateTime.format(formatter)
+    val text = when (localDate) {
+        LocalDate.now() -> "Today"
+        LocalDate.now().minusDays(1) -> "Yesterday"
+        else -> localDate.format(formatter)
+    }
+    return text
 }
 
 fun searchMessages(messages: List<ChatMessage>, searchId: String): Int {

app/src/main/java/com/nextcloud/talk/utils/preview/ComposePreviewUtilsDaos.kt

@@ -29,6 +29,12 @@ class DummyChatMessagesDaoImpl : ChatMessagesDao {
         oldestMessageId: Long
     ): Flow<List<ChatMessageEntity>> = flowOf()
 
+    override fun getMessagesNewerThanForChatKit(
+        internalConversationId: String,
+        threadId: Long?,
+        oldestMessageId: Long
+    ): Flow<List<ChatMessageEntity>> = flowOf()
+
     override fun getMessagesForConversation(
         internalConversationId: String,
         threadId: Long?