fix(chat/messages): set clock value for new messages marker

New messages marker had a clock value of "0" before. Since all
messages are inserted based on the clock value, new messages marker
would cause other "0"-valued clock items to be inserted after it,
effectively making chat header being displayed in the middle of the
chat.

Setting new messages marker clock value to the clock of the message it
points to solves the issue.

fixes: #8955

src/app/modules/shared_models/message_item.nim

@@ -131,7 +131,7 @@ proc initItem*(
       if attachment.contentType.contains("image"):
         result.messageAttachments.add(attachment.localUrl)
 
-proc initNewMessagesMarkerItem*(timestamp: int64): Item =
+proc initNewMessagesMarkerItem*(clock, timestamp: int64): Item =
   return initItem(
     id = "",
     communityId = "",
@@ -148,7 +148,7 @@ proc initNewMessagesMarkerItem*(timestamp: int64): Item =
     messageContainsMentions = false,
     seen = true,
     timestamp = timestamp,
-    clock = 0,
+    clock = clock,
     ContentType.NewMessagesMarker,
     messageType = -1,
     contactRequestState = 0,

src/app/modules/shared_models/message_model.nim

@@ -569,7 +569,7 @@ QtObject:
     defer: parentModelIndex.delete
 
     self.beginInsertRows(parentModelIndex, position, position)
-    self.items.insert(initNewMessagesMarkerItem(self.items[index].timestamp), position)
+    self.items.insert(initNewMessagesMarkerItem(self.items[index].clock, self.items[index].timestamp), position)
     self.endInsertRows()
     self.countChanged()
 

test/nim/message_model_test.nim

@@ -26,7 +26,7 @@ proc createTestMessageItem(id: string, clock: int64): Item =
     seen = true,
     timestamp = 0,
     clock = clock,
-    ContentType.NewMessagesMarker,
+    ContentType.Unknown,
     messageType = -1,
     contactRequestState = 0,
     sticker = "",
@@ -41,19 +41,23 @@ proc createTestMessageItem(id: string, clock: int64): Item =
     mentioned = false
   )
 
+let message0_chatIdentifier = createTestMessageItem("chat-identifier", 0)
+let message0_fetchMoreMessages = createTestMessageItem("fetch-more-messages", 0)
 let message1 = createTestMessageItem("0xa", 1)
 let message2 = createTestMessageItem("0xb", 2)
 let message3 = createTestMessageItem("0xc", 3)
 let message4 = createTestMessageItem("0xd", 3)
 let message5 = createTestMessageItem("0xe", 4)
 
 template checkOrder(model: Model) =
-  require(model.items.len == 5)
+  require(model.items.len == 7)
   check(model.items[0].id == message5.id)
   check(model.items[1].id == message4.id)
   check(model.items[2].id == message3.id)
   check(model.items[3].id == message2.id)
   check(model.items[4].id == message1.id)
+  check(model.items[5].id == message0_fetchMoreMessages.id)
+  check(model.items[6].id == message0_chatIdentifier.id)
 
 suite "empty model":
   let model = newModel()
@@ -65,56 +69,60 @@ suite "empty model":
 suite "inserting new messages":
   setup:
     let model = newModel()
+    model.appendItem(message0_fetchMoreMessages)
+    model.appendItem(message0_chatIdentifier)
 
   test "insert same message twice":
     model.insertItemBasedOnClock(message1)
-    check(model.rowCount() == 1)
+    check(model.rowCount() == 3)
     model.insertItemBasedOnClock(message1)
-    check(model.rowCount() == 1)
+    check(model.rowCount() == 3)
 
   test "insert in order":
     model.insertItemBasedOnClock(message1)
-    check(model.rowCount() == 1)
+    check(model.rowCount() == 3)
     model.insertItemBasedOnClock(message2)
-    check(model.rowCount() == 2)
+    check(model.rowCount() == 4)
     model.insertItemBasedOnClock(message3)
-    check(model.rowCount() == 3)
+    check(model.rowCount() == 5)
     model.insertItemBasedOnClock(message4)
-    check(model.rowCount() == 4)
+    check(model.rowCount() == 6)
     model.insertItemBasedOnClock(message5)
-    check(model.rowCount() == 5)
+    check(model.rowCount() == 7)
     checkOrder(model)
 
   test "insert out of order":
     model.insertItemBasedOnClock(message5)
-    check(model.rowCount() == 1)
+    check(model.rowCount() == 3)
     model.insertItemBasedOnClock(message4)
-    check(model.rowCount() == 2)
+    check(model.rowCount() == 4)
     model.insertItemBasedOnClock(message3)
-    check(model.rowCount() == 3)
+    check(model.rowCount() == 5)
     model.insertItemBasedOnClock(message2)
-    check(model.rowCount() == 4)
+    check(model.rowCount() == 6)
     model.insertItemBasedOnClock(message1)
-    check(model.rowCount() == 5)
+    check(model.rowCount() == 7)
     checkOrder(model)
 
   test "insert out of order (randomly)":
     model.insertItemBasedOnClock(message3)
-    check(model.rowCount() == 1)
+    check(model.rowCount() == 3)
     model.insertItemBasedOnClock(message1)
-    check(model.rowCount() == 2)
+    check(model.rowCount() == 4)
     model.insertItemBasedOnClock(message4)
-    check(model.rowCount() == 3)
+    check(model.rowCount() == 5)
     model.insertItemBasedOnClock(message2)
-    check(model.rowCount() == 4)
+    check(model.rowCount() == 6)
     model.insertItemBasedOnClock(message5)
-    check(model.rowCount() == 5)
+    check(model.rowCount() == 7)
     checkOrder(model)
 
 # assumption: each append sequence is already sorted
 suite "appending new messages":
   setup:
     let model = newModel()
+    model.appendItem(message0_fetchMoreMessages)
+    model.appendItem(message0_chatIdentifier)
 
   test "append empty model":
     model.appendItems(@[message5,
@@ -147,3 +155,142 @@ suite "appending new messages":
     model.appendItems(@[message4,
                         message2])
     checkOrder(model)
+
+suite "new messages marker":
+  setup:
+    let model = newModel()
+    model.appendItem(message0_fetchMoreMessages)
+    model.appendItem(message0_chatIdentifier)
+
+  test "set new messages marker":
+    model.appendItems(@[message1,
+                        message2])
+    require(model.items.len == 4)
+
+    # add new messages marker
+    model.setFirstUnseenMessageId(message2.id)
+    model.resetNewMessagesMarker()
+
+    require(model.items.len == 5)
+    check(model.items[0].id == message2.id)
+    check(model.items[1].contentType == ContentType.NewMessagesMarker)
+    check(model.items[2].id == message1.id)
+    check(model.items[3].id == message0_fetchMoreMessages.id)
+    check(model.items[4].id == message0_chatIdentifier.id)
+
+  test "remove new messages marker":
+    model.appendItems(@[message1,
+                        message2])
+    require(model.items.len == 4)
+
+    # add new messages marker
+    model.setFirstUnseenMessageId(message2.id)
+    model.resetNewMessagesMarker()
+    require(model.items.len == 5)
+
+    # remove new messages marker
+    model.setFirstUnseenMessageId("")
+    model.resetNewMessagesMarker()
+    require(model.items.len == 4)
+    check(model.items[0].id == message2.id)
+    check(model.items[1].id == message1.id)
+    check(model.items[2].id == message0_fetchMoreMessages.id)
+    check(model.items[3].id == message0_chatIdentifier.id)
+
+suite "simulations":
+  setup:
+    let model = newModel()
+    model.appendItem(message0_fetchMoreMessages)
+    model.appendItem(message0_chatIdentifier)
+
+  test "simulate messages loading":
+    # load first two messages
+    var loadedMessages: seq[Item]
+    loadedMessages.add(message5)
+    loadedMessages.add(message4)
+    model.removeItem(message0_fetchMoreMessages.id)
+    model.removeItem(message0_chatIdentifier.id)
+    loadedMessages.add(message0_fetchMoreMessages)
+    loadedMessages.add(message0_chatIdentifier)
+    model.appendItems(loadedMessages)
+
+    require(model.items.len == 4)
+    check(model.items[0].id == message5.id)
+    check(model.items[1].id == message4.id)
+    check(model.items[2].id == message0_fetchMoreMessages.id)
+    check(model.items[3].id == message0_chatIdentifier.id)
+
+    # set new messages marker
+    model.setFirstUnseenMessageId(message5.id)
+    model.resetNewMessagesMarker()
+
+    require(model.items.len == 5)
+    check(model.items[0].id == message5.id)
+    check(model.items[1].contentType == ContentType.NewMessagesMarker)
+    check(model.items[2].id == message4.id)
+    check(model.items[3].id == message0_fetchMoreMessages.id)
+    check(model.items[4].id == message0_chatIdentifier.id)
+
+    # load next two messages
+    loadedMessages = @[]
+    loadedMessages.add(message3)
+    loadedMessages.add(message2)
+    model.removeItem(message0_fetchMoreMessages.id)
+    model.removeItem(message0_chatIdentifier.id)
+    loadedMessages.add(message0_fetchMoreMessages)
+    loadedMessages.add(message0_chatIdentifier)
+    model.appendItems(loadedMessages)
+
+    require(model.items.len == 7)
+    check(model.items[0].id == message5.id)
+    check(model.items[1].contentType == ContentType.NewMessagesMarker)
+    check(model.items[2].id == message4.id)
+    check(model.items[3].id == message3.id)
+    check(model.items[4].id == message2.id)
+    check(model.items[5].id == message0_fetchMoreMessages.id)
+    check(model.items[6].id == message0_chatIdentifier.id)
+
+    # load last message
+    loadedMessages = @[]
+    loadedMessages.add(message1)
+    model.removeItem(message0_fetchMoreMessages.id)
+    model.removeItem(message0_chatIdentifier.id)
+    loadedMessages.add(message0_fetchMoreMessages)
+    loadedMessages.add(message0_chatIdentifier)
+    model.appendItems(loadedMessages)
+
+    require(model.items.len == 8)
+    check(model.items[0].id == message5.id)
+    check(model.items[1].contentType == ContentType.NewMessagesMarker)
+    check(model.items[2].id == message4.id)
+    check(model.items[3].id == message3.id)
+    check(model.items[4].id == message2.id)
+    check(model.items[5].id == message1.id)
+    check(model.items[6].id == message0_fetchMoreMessages.id)
+    check(model.items[7].id == message0_chatIdentifier.id)
+
+  test "simulate chat identifier update":
+    model.appendItems(@[message5,
+                        message4,
+                        message3,
+                        message2,
+                        message1])
+    checkOrder(model)
+
+    # set new messages marker
+    model.setFirstUnseenMessageId(message4.id)
+    model.resetNewMessagesMarker()
+
+    # update chat identifier
+    model.removeItem(message0_chatIdentifier.id)
+    model.appendItem(message0_chatIdentifier)
+
+    require(model.items.len == 8)
+    check(model.items[0].id == message5.id)
+    check(model.items[1].id == message4.id)
+    check(model.items[2].contentType == ContentType.NewMessagesMarker)
+    check(model.items[3].id == message3.id)
+    check(model.items[4].id == message2.id)
+    check(model.items[5].id == message1.id)
+    check(model.items[6].id == message0_fetchMoreMessages.id)
+    check(model.items[7].id == message0_chatIdentifier.id)