prevent disappearing message affecting the order of conversations

SessionMessagingKit/Database/TSDatabaseView.m

@@ -278,15 +278,8 @@ NSString *const TSLazyRestoreAttachmentsGroup = @"TSLazyRestoreAttachmentsGroup"
         TSThread *thread1 = (TSThread *)object1;
         TSThread *thread2 = (TSThread *)object2;
         if ([group isEqualToString:TSArchiveGroup] || [group isEqualToString:TSInboxGroup]) {
-
+            NSDate *date1 = thread1.lastInteractionDate ?: thread1.creationDate;
-            TSInteraction *_Nullable lastInteractionForInbox1 =
+            NSDate *date2 = thread2.lastInteractionDate ?: thread2.creationDate;
-                [thread1 lastInteractionForInboxWithTransaction:transaction];
-            NSDate *date1 = lastInteractionForInbox1 ? lastInteractionForInbox1.receivedAtDate : thread1.creationDate;
-
-            TSInteraction *_Nullable lastInteractionForInbox2 =
-                [thread2 lastInteractionForInboxWithTransaction:transaction];
-            NSDate *date2 = lastInteractionForInbox2 ? lastInteractionForInbox2.receivedAtDate : thread2.creationDate;
-
             return [date1 compare:date2];
         }
 

SessionMessagingKit/Threads/TSThread.h

@@ -18,6 +18,7 @@ BOOL IsNoteToSelfEnabled(void);
 
 @property (nonatomic) BOOL shouldBeVisible;
 @property (nonatomic, readonly) NSDate *creationDate;
+@property (nonatomic, readonly, nullable) NSDate *lastInteractionDate;
 @property (nonatomic, readonly) TSInteraction *lastInteraction;
 @property (atomic, readonly) BOOL isMuted;
 @property (atomic, readonly, nullable) NSDate *mutedUntilDate;

SessionMessagingKit/Threads/TSThread.m

@@ -21,6 +21,7 @@ BOOL IsNoteToSelfEnabled(void)
 @interface TSThread ()
 
 @property (nonatomic) NSDate *creationDate;
+@property (nonatomic, nullable) NSDate *lastInteractionDate;
 @property (nonatomic, nullable) NSNumber *archivedAsOfMessageSortId;
 @property (nonatomic, copy, nullable) NSString *messageDraft;
 @property (atomic, nullable) NSDate *mutedUntilDate;
@@ -356,6 +357,8 @@ BOOL IsNoteToSelfEnabled(void)
         return;
     }
     
+    _lastInteractionDate = lastMessage.receivedAtDate;
+
     if (!self.shouldBeVisible) {
         self.shouldBeVisible = YES;
         [self saveWithTransaction:transaction];