Message grouping

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

@@ -25,6 +25,8 @@ import java.util.Date
 data class ChatMessage(
     var isGrouped: Boolean = false,
 
+    var isGroupedWithNext: Boolean = false,
+
     var isOneToOneConversation: Boolean = false,
 
     var isFormerOneToOneConversation: Boolean = false,

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

@@ -43,7 +43,9 @@ data class ChatMessageUi(
     val reactions: List<MessageReactionUi> = emptyList(),
     val isEdited: Boolean = false,
     val parentMessage: ChatMessageUi? = null,
-    val replyable: Boolean = false
+    val replyable: Boolean = false,
+    val isGrouped: Boolean = false,
+    val isGroupedWithNext: Boolean = false
 )
 
 data class MessageReactionUi(val emoji: String, val amount: Int, val isSelfReaction: Boolean)
@@ -125,7 +127,9 @@ fun ChatMessage.toUiModel(
             lastCommonReadMessageId = 0,
             parentMessage = null
         ),
-        replyable = replyable
+        replyable = replyable,
+        isGrouped = isGrouped,
+        isGroupedWithNext = isGroupedWithNext
     )
 
 private fun ChatMessage.normalizeMessageParameters(): Map<String, Map<String, String>> =

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

@@ -102,7 +102,9 @@ import kotlinx.coroutines.withTimeoutOrNull
 import retrofit2.HttpException
 import java.io.File
 import java.io.IOException
+import java.time.Instant
 import java.time.LocalDate
+import java.time.ZoneId
 import javax.inject.Inject
 
 @Suppress("TooManyFunctions", "LongParameterList")
@@ -649,6 +651,7 @@ class ChatViewModel @AssistedInject constructor(
                         .distinct()
 
                 val user = currentUserFlow.value
+                applyMessageGrouping(messages)
                 val uiMessages = messages.map { message ->
                     val parent: ChatMessage? = combinedMap[message.parentMessageId]
                     message.toUiModel(
@@ -716,6 +719,34 @@ class ChatViewModel @AssistedInject constructor(
         }.asReversed()
     }
 
+    private fun applyMessageGrouping(messages: List<ChatMessage>) {
+        messages.forEachIndexed { index, message ->
+            message.isGrouped = index > 0 && shouldGroupMessage(message, messages[index - 1])
+            message.isGroupedWithNext = index < messages.size - 1 && shouldGroupMessage(messages[index + 1], message)
+        }
+    }
+
+    private fun shouldGroupMessage(current: ChatMessage, previous: ChatMessage): Boolean {
+        val sameMessageKind = current.isSystemMessage == previous.isSystemMessage
+        val notUnclassifiedBot = current.actorType != "bots" || current.actorId == "changelog"
+        val sameActor = current.isSystemMessage ||
+            (current.actorType == previous.actorType && current.actorId == previous.actorId)
+        val currentDate = Instant.ofEpochMilli(current.timestamp * TIMESTAMP_TO_MILLIS)
+            .atZone(ZoneId.systemDefault()).toLocalDate()
+        val previousDate = Instant.ofEpochMilli(previous.timestamp * TIMESTAMP_TO_MILLIS)
+            .atZone(ZoneId.systemDefault()).toLocalDate()
+        val timeDifference = kotlin.math.abs(current.timestamp - previous.timestamp)
+        val neitherEdited = (current.lastEditTimestamp ?: 0L) == 0L || (previous.lastEditTimestamp ?: 0L) == 0L
+
+        return sameMessageKind &&
+            notUnclassifiedBot &&
+            sameActor &&
+            currentDate == previousDate &&
+            current.actorId == previous.actorId &&
+            timeDifference <= GROUPING_TIME_WINDOW_SECONDS &&
+            neitherEdited
+    }
+
     fun onMessageSent() {
         oneOrMoreMessagesWereSent = true
     }
@@ -1775,6 +1806,8 @@ class ChatViewModel @AssistedInject constructor(
         private const val WEBSOCKET_CONNECT_TIMEOUT_MS = 3000L
         private const val WEBSOCKET_POLL_INTERVAL_MS = 50L
         private const val ROOM_REFRESH_DEBOUNCE_MS = 500L
+        private const val GROUPING_TIME_WINDOW_SECONDS = 300L
+        private const val TIMESTAMP_TO_MILLIS = 1000L
     }
 
     sealed class OutOfOfficeUIState {

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

@@ -113,3 +113,22 @@ internal fun createLongBaseMessage(content: MessageTypeContent?): ChatMessageUi
         content = content,
         reactions = previewReactions
     )
+
+internal fun createMarkdownMessage(): ChatMessageUi =
+    ChatMessageUi(
+        id = 4,
+        message = "- Item 1\n- Item 2\n\n> A blockquote\n\n```kotlin\nval x = 1\n```",
+        plainMessage = "- Item 1\n- Item 2\n\n> A blockquote\n\n```kotlin\nval x = 1\n```",
+        renderMarkdown = true,
+        actorDisplayName = "Markdown Sender",
+        isThread = false,
+        threadTitle = "",
+        threadReplies = 0,
+        incoming = true,
+        isDeleted = false,
+        avatarUrl = null,
+        statusIcon = MessageStatusIcon.SENT,
+        timestamp = System.currentTimeMillis() / 1000,
+        date = LocalDate.now(),
+        content = MessageTypeContent.RegularText
+    )