revert isPlausibleLastReadMessageId check

Checking the real data for a big instance unveiled i was pretty off with my assumption how high the difference between messageId and newestKnownRealMessageId could be.

Logging for C.N.C was:
"advanceLocalLastReadMessageIfNeeded, messageId (5748751) is implausibly higher than the conversation's newest known message id (5694085). We won't advance."

I wont go down that road to increase PLAUSIBLE_MESSAGE_ID_BUFFER every know and then when it turns out it is still too low.

The curretn logic might introduce more problems than it would solve.
There should be other checks to make sure readmarkers don't make it to the server when they are wrong.

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

Author: mahibi

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

@@ -1845,17 +1845,6 @@ class ChatViewModel @AssistedInject constructor(
         Log.d(TAG, "advanceLocalLastReadMessageIfNeeded, messageId: $messageId")
         Log.d(TAG, "advanceLocalLastReadMessageIfNeeded, localLastReadMessage: $localLastReadMessage")
 
-        val newestKnownRealMessageId = _uiState.value.conversation?.lastMessage?.id
-
-        if (!isPlausibleLastReadMessageId(messageId, newestKnownRealMessageId)) {
-            logger.w(
-                TAG,
-                "advanceLocalLastReadMessageIfNeeded, messageId ($messageId) is implausibly higher than the " +
-                    "conversation's newest known message id ($newestKnownRealMessageId). We won't advance."
-            )
-            return
-        }
-
         if (localLastReadMessage < messageId && -1 < messageId) {
             Log.d(TAG, "advanceLocalLastReadMessageIfNeeded, setting localLastReadMessage to $messageId")
             localLastReadMessage = messageId
@@ -2487,18 +2476,6 @@ class ChatViewModel @AssistedInject constructor(
         // cycle (up to 2 minutes later) before its "sent, not yet confirmed" spinner clears.
         private val POST_UPLOAD_FETCH_RETRY_DELAYS_MS = listOf(1_000L, 1_500L, 2_000L, 3_000L, 4_000L, 5_000L, 5_000L)
         private const val LOCAL_PREVIEW_GRACE_PERIOD_MS = 15_000L
-        private const val PLAUSIBLE_MESSAGE_ID_BUFFER = 10_000L
-
-        /**
-         * A real server-assigned message id is always positive, so a null, zero or negative
-         * [newestKnownRealMessageId] is never a trustworthy ceiling to judge [messageId] against -
-         * e.g. a federated conversation's cached lastMessage can carry an id of 0 when it was
-         * never populated. Without a trustworthy ceiling, [messageId] is accepted unchecked here.
-         */
-        fun isPlausibleLastReadMessageId(messageId: Int, newestKnownRealMessageId: Long?): Boolean {
-            val trustworthyCeiling = newestKnownRealMessageId?.takeIf { it > 0 } ?: return true
-            return messageId <= trustworthyCeiling + PLAUSIBLE_MESSAGE_ID_BUFFER
-        }
     }
 
     sealed class OutOfOfficeUIState {

app/src/test/java/com/nextcloud/talk/chat/viewmodels/ChatViewModelTest.kt

@@ -19,55 +19,6 @@ import java.time.LocalDate
 
 class ChatViewModelTest {
 
-    @Test
-    fun `isPlausibleLastReadMessageId returns true when there is no known real message id yet`() {
-        assertTrue(ChatViewModel.isPlausibleLastReadMessageId(messageId = 158761, newestKnownRealMessageId = null))
-    }
-
-    @Test
-    fun `isPlausibleLastReadMessageId returns true for the newest known real message id itself`() {
-        assertTrue(ChatViewModel.isPlausibleLastReadMessageId(messageId = 158761, newestKnownRealMessageId = 158761L))
-    }
-
-    @Test
-    fun `isPlausibleLastReadMessageId returns true for an older message id`() {
-        assertTrue(ChatViewModel.isPlausibleLastReadMessageId(messageId = 100, newestKnownRealMessageId = 158761L))
-    }
-
-    @Test
-    fun `isPlausibleLastReadMessageId returns true within the buffer above the newest known message id`() {
-        assertTrue(
-            ChatViewModel.isPlausibleLastReadMessageId(
-                messageId = 158761 + 10_000,
-                newestKnownRealMessageId = 158761L
-            )
-        )
-    }
-
-    @Test
-    fun `isPlausibleLastReadMessageId returns false just beyond the buffer above the newest known message id`() {
-        assertFalse(
-            ChatViewModel.isPlausibleLastReadMessageId(
-                messageId = 158761 + 10_000 + 1,
-                newestKnownRealMessageId = 158761L
-            )
-        )
-    }
-
-    @Test
-    fun `isPlausibleLastReadMessageId rejects a hash-derived placeholder id far beyond the real message id space`() {
-        assertFalse(
-            ChatViewModel.isPlausibleLastReadMessageId(messageId = 1_963_726_147, newestKnownRealMessageId = 158761L)
-        )
-    }
-
-    @Test
-    fun `isPlausibleLastReadMessageId treats a newest known id of 0 as unknown`() {
-        // A federated conversation's cached lastMessage can carry an id of 0 - a real message id
-        // is never 0, so this must not be treated as a real ceiling near the start of the room.
-        assertTrue(ChatViewModel.isPlausibleLastReadMessageId(messageId = 136556, newestKnownRealMessageId = 0L))
-    }
-
     // The unread marker latch: the marker position must only be derived from the visible window
     // when the window provably reaches back to the unread boundary — otherwise a window of
     // only-unread messages (e.g. after a capped fetch of the newest messages) would place the