From 181c0e8a60a8087dcc847cf49f435dbcdf52fea1 Mon Sep 17 00:00:00 2001
From: Alex Hart <alex@signal.org>
Date: Tue, 8 Aug 2023 16:35:30 -0300
Subject: [PATCH] Revert "Fix unread state using last seen timestamp."

This reverts commit a5e30bc818ebf13d53b6cd72f26e988fd12757a8.
---
 .../conversation/v2/ConversationFragment.kt   |  2 +-
 .../v2/ConversationItemDecorations.kt         | 23 ++++++++-----------
 2 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationFragment.kt b/app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationFragment.kt
index 15bb7cfcf4..1ed7497c5c 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationFragment.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationFragment.kt
@@ -830,7 +830,7 @@ class ConversationFragment :
       .doOnSuccess { state ->
         adapter.setMessageRequestIsAccepted(state.meta.messageRequestData.isMessageRequestAccepted)
         SignalLocalMetrics.ConversationOpen.onDataLoaded()
-        conversationItemDecorations.setFirstUnreadState(state.meta.lastSeen)
+        conversationItemDecorations.setFirstUnreadCount(state.meta.unreadCount)
         colorizer.onGroupMembershipChanged(state.meta.groupMemberAcis)
       }
       .observeOn(AndroidSchedulers.mainThread())
diff --git a/app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationItemDecorations.kt b/app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationItemDecorations.kt
index a02d780588..5c8db86ec4 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationItemDecorations.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationItemDecorations.kt
@@ -94,15 +94,15 @@ class ConversationItemDecorations(hasWallpaper: Boolean = false, private val sch
   }
 
   /** Must be called before first setting of [currentItems] */
-  fun setFirstUnreadState(lastSeenTimestamp: Long) {
-    if (unreadState == UnreadState.None && lastSeenTimestamp > 0) {
-      unreadState = UnreadState.InitialUnreadState(lastSeenTimestamp = lastSeenTimestamp)
+  fun setFirstUnreadCount(unreadCount: Int) {
+    if (unreadState == UnreadState.None && unreadCount > 0) {
+      unreadState = UnreadState.InitialUnreadState(unreadCount)
     }
   }
 
   /**
    * If [unreadState] is [UnreadState.InitialUnreadState] we need to determine the first unread timestamp based on
-   * last seen timestamp.
+   * initial unread count.
    *
    * Once in [UnreadState.CompleteUnreadState], need to update the unread count based on new incoming messages since
    * the first unread timestamp. If an outgoing message is found in this range the unread state is cleared completely,
@@ -112,15 +112,10 @@ class ConversationItemDecorations(hasWallpaper: Boolean = false, private val sch
     val state: UnreadState = unreadState
 
     if (state is UnreadState.InitialUnreadState) {
-      val firstUnread = items
-        .filterIsInstance<ConversationMessageElement>()
-        .lastOrNull { it.timestamp() > state.lastSeenTimestamp }
-
-      if (firstUnread != null) {
-        unreadState = UnreadState.CompleteUnreadState(
-          unreadCount = items.indexOf(firstUnread as ConversationElement?) + 1,
-          firstUnreadTimestamp = firstUnread.timestamp()
-        )
+      val firstUnread = items[(state.unreadCount - 1).coerceIn(items.indices)]
+      val timestamp = (firstUnread as? ConversationMessageElement)?.timestamp()
+      if (timestamp != null) {
+        unreadState = UnreadState.CompleteUnreadState(unreadCount = state.unreadCount, firstUnreadTimestamp = timestamp)
       }
     } else if (state is UnreadState.CompleteUnreadState) {
       var newUnreadCount = 0
@@ -275,7 +270,7 @@ class ConversationItemDecorations(hasWallpaper: Boolean = false, private val sch
     object None : UnreadState()
 
     /** On first load of data, there is at least 1 unread message but we don't know the 'position' in the list yet */
-    data class InitialUnreadState(val lastSeenTimestamp: Long) : UnreadState()
+    data class InitialUnreadState(val unreadCount: Int) : UnreadState()
 
     /** We have at least one unread and know the timestamp of the first unread message and thus 'position' for the header */
     data class CompleteUnreadState(val unreadCount: Int, val firstUnreadTimestamp: Long? = null) : UnreadState()