[i231] Old messages are read by newly added member

CHANGELOG.md

@@ -61,6 +61,7 @@
 
 ## stream-chat-android-ui-components
 ### 🐞 Fixed
+- Fixed old messages being marked as read by freshly added members. [#5138](https://github.com/GetStream/stream-chat-android/pull/5138)
 
 ### ⬆️ Improved
 

stream-chat-android-core/src/main/java/io/getstream/chat/android/core/utils/date/DateUtils.kt

@@ -20,6 +20,7 @@ package io.getstream.chat.android.core.utils.date
 
 import io.getstream.chat.android.core.internal.InternalStreamChatApi
 import java.util.Date
+import kotlin.math.abs
 
 /**
  * Tests if [this] date is after [that] date.
@@ -47,3 +48,11 @@ public fun max(dateA: Date?, dateB: Date?): Date? = when (dateA after dateB) {
  */
 @InternalStreamChatApi
 public fun Date.inOffsetWith(other: Date, offset: Long): Boolean = (time + offset) >= other.time
+
+/**
+ * Returns difference between [this] date and [that] date in [TimeDuration].
+ */
+@InternalStreamChatApi
+public fun Date.diff(that: Date): Long {
+    return abs(time - that.time)
+}

stream-chat-android-ui-components/src/main/kotlin/com/getstream/sdk/chat/viewmodel/messages/MessageListItemLiveData.kt

@@ -25,11 +25,14 @@ import com.getstream.sdk.chat.utils.extensions.combineWith
 import com.getstream.sdk.chat.utils.extensions.getCreatedAtOrThrow
 import com.getstream.sdk.chat.utils.extensions.shouldShowMessageFooter
 import com.getstream.sdk.chat.view.messages.MessageListItemWrapper
+import io.getstream.chat.android.client.ChatClient
 import io.getstream.chat.android.client.models.ChannelUserRead
+import io.getstream.chat.android.client.models.Member
 import io.getstream.chat.android.client.models.Message
 import io.getstream.chat.android.client.models.User
 import io.getstream.chat.android.common.state.DeletedMessageVisibility
 import io.getstream.chat.android.common.state.MessageFooterVisibility
+import io.getstream.chat.android.core.utils.date.diff
 import io.getstream.chat.android.ui.ChatUI
 
 /**
@@ -88,6 +91,7 @@ internal class MessageListItemLiveData(
     private val deletedMessageVisibility: LiveData<DeletedMessageVisibility>,
     private val messageFooterVisibility: LiveData<MessageFooterVisibility>,
     private val messagePositionHandlerProvider: () -> MessageListViewModel.MessagePositionHandler,
+    private val getMembers: () -> List<Member>,
 ) : MediatorLiveData<MessageListItemWrapper>() {
 
     private var hasNewMessages: Boolean = false
@@ -339,8 +343,9 @@ internal class MessageListItemLiveData(
     ): List<MessageListItem> {
         if (reads == null || messages.isEmpty()) return messages
         // filter your own read status and sort by last read
+        val membersMap = getMembers().associateBy { it.user.id }
         val sortedReads = reads
-            .filter { it.user.id != currentUserId }
+            .filter { it.user.id != currentUserId && !it.belongsToFreshlyAddedMember(membersMap) }
             .filterNot { it.lastRead == null }
             .sortedBy { it.lastRead }
             .toMutableList()
@@ -388,8 +393,9 @@ internal class MessageListItemLiveData(
         reads: List<ChannelUserRead>,
         currentUserId: String,
     ): List<MessageListItem> {
+        val membersMap = getMembers().associateBy { it.user.id }
         val lastRead = reads
-            .filter { it.user.id != currentUserId }
+            .filter { it.user.id != currentUserId && !it.belongsToFreshlyAddedMember(membersMap) }
             .mapNotNull { it.lastRead }
             .maxOrNull() ?: return messages
 
@@ -448,4 +454,21 @@ internal class MessageListItemLiveData(
     internal fun updateDateSeparatorHandlers(dateSeparatorHandler: MessageListViewModel.DateSeparatorHandler?) {
         this.dateSeparatorHandler = dateSeparatorHandler
     }
+
+    /**
+     * Checks if [ChannelUserRead] belongs to a freshly added member.
+     *
+     * It is used to determine if this member explicitly read this channel using [ChatClient.markRead].
+     */
+    private fun ChannelUserRead.belongsToFreshlyAddedMember(
+        membersMap: Map<String, Member>,
+    ): Boolean {
+        val member = membersMap[user.id]
+        val membershipAndLastReadDiff = lastRead?.let { member?.createdAt?.diff(it) } ?: Long.MAX_VALUE
+        return membershipAndLastReadDiff < MEMBERSHIP_AND_LAST_READ_THRESHOLD_MS
+    }
+
+    private companion object {
+        private const val MEMBERSHIP_AND_LAST_READ_THRESHOLD_MS = 100L
+    }
 }

stream-chat-android-ui-components/src/main/kotlin/com/getstream/sdk/chat/viewmodel/messages/MessageListViewModel.kt

@@ -349,6 +349,7 @@ public class MessageListViewModel(
             deletedMessageVisibility = deletedMessageVisibility,
             messageFooterVisibility = messageFooterVisibility,
             messagePositionHandlerProvider = ::messagePositionHandler,
+            getMembers = { channelState.members.value },
         )
         _reads.addSource(channelState.reads.asLiveData()) { _reads.value = it }
         _loadMoreLiveData.addSource(channelState.loadingOlderMessages.asLiveData()) { _loadMoreLiveData.value = it }
@@ -397,6 +398,7 @@ public class MessageListViewModel(
             deletedMessageVisibility = deletedMessageVisibility,
             messageFooterVisibility = messageFooterVisibility,
             messagePositionHandlerProvider = ::messagePositionHandler,
+            getMembers = { channelState.value?.members?.value ?: emptyList() },
         )
         threadListData?.let { tld ->
             messageListData?.let { mld ->

stream-chat-android-ui-components/src/test/kotlin/io/getstream/chat/android/ui/MessageListItemLiveDataTest.kt

@@ -90,6 +90,7 @@ internal class MessageListItemLiveDataTest {
             deletedMessageVisibility = deletedMessageVisibility,
             messageFooterVisibility = messageFooterVisibility,
             messagePositionHandlerProvider = MessageListViewModel.MessagePositionHandler::defaultHandler,
+            members = channelState.members.asLiveData(),
         )
     }
 
@@ -110,6 +111,7 @@ internal class MessageListItemLiveDataTest {
             deletedMessageVisibility = deletedMessageVisibility,
             messageFooterVisibility = messageFooterVisibility,
             messagePositionHandlerProvider = MessageListViewModel.MessagePositionHandler::defaultHandler,
+            members = channelState.members.asLiveData(),
         )
     }
 
@@ -145,6 +147,7 @@ internal class MessageListItemLiveDataTest {
             deletedMessageVisibility = deletedMessageVisibility,
             messageFooterVisibility = messageFooterVisibility,
             messagePositionHandlerProvider = MessageListViewModel.MessagePositionHandler::defaultHandler,
+            members = channelState.members.asLiveData(),
         )
     }