use TSIncomingMessage's serverTimastamp to make more sense

SessionMessagingKit/Database/Storage+Messaging.swift

@@ -42,9 +42,6 @@ extension Storage {
         } else {
             tsMessage = TSIncomingMessage.from(message, quotedMessage: quotedMessage, linkPreview: linkPreview, associatedWith: thread)
         }
-        if let serverTimestamp = message.receivedTimestamp, openGroupID != nil {
-            tsMessage.setServerTimestampToReceivedTimestamp(serverTimestamp)
-        }
         tsMessage.save(with: transaction)
         tsMessage.attachments(with: transaction).forEach { attachment in
             attachment.albumMessageId = tsMessage.uniqueId!

SessionMessagingKit/Messages/Message.swift

@@ -10,6 +10,7 @@ public class Message : NSObject, NSCoding { // NSObject/NSCoding conformance is
     public var sender: String?
     public var groupPublicKey: String?
     public var openGroupServerMessageID: UInt64?
+    public var openGroupServerTimestamp: UInt64?
 
     public var ttl: UInt64 { 2 * 24 * 60 * 60 * 1000 }
     public var isSelfSendValid: Bool { false }

SessionMessagingKit/Messages/Signal/TSIncomingMessage+Conversion.swift

@@ -19,7 +19,7 @@ public extension TSIncomingMessage {
             expiresInSeconds: !isOpenGroupMessage ? expiration : 0, // Ensure we don't ever expire open group messages
             quotedMessage: quotedMessage,
             linkPreview: linkPreview,
-            serverTimestamp: nil,
+            serverTimestamp: visibleMessage.openGroupServerTimestamp as NSNumber?,
             wasReceivedByUD: true
         )
         result.openGroupServerMessageID = openGroupServerMessageID

SessionMessagingKit/Messages/Signal/TSInteraction.h

@@ -41,8 +41,6 @@ NSString *NSStringFromOWSInteractionType(OWSInteractionType value);
 @property (nonatomic, readonly) uint64_t receivedAtTimestamp;
 @property (nonatomic, readonly) BOOL shouldUseServerTime;
 
-- (void)setServerTimestampToReceivedTimestamp:(uint64_t)receivedAtTimestamp;
-
 - (uint64_t)timestampForUI;
 
 - (NSDate *)receivedAtDate;

SessionMessagingKit/Messages/Signal/TSInteraction.m

@@ -169,8 +169,8 @@ NSString *NSStringFromOWSInteractionType(OWSInteractionType value)
 
 - (uint64_t)timestampForUI
 {
-    if (_shouldUseServerTime) {
-        return _receivedAtTimestamp;
+    if ([self isKindOfClass:TSIncomingMessage.class] && ((TSIncomingMessage *)self).isOpenGroupMessage) {
+        return ((TSIncomingMessage *)self).serverTimestamp.unsignedLongLongValue;
     }
     return _timestamp;
 }
@@ -180,14 +180,11 @@ NSString *NSStringFromOWSInteractionType(OWSInteractionType value)
     return self.timestamp;
 }
 
-- (void)setServerTimestampToReceivedTimestamp:(uint64_t)receivedAtTimestamp
-{
-    _shouldUseServerTime = YES;
-    _receivedAtTimestamp = receivedAtTimestamp;
-}
-
 - (NSDate *)receivedAtDate
 {
+    if ([self isKindOfClass:TSIncomingMessage.class] && ((TSIncomingMessage *)self).isOpenGroupMessage) {
+        return [NSDate ows_dateWithMillisecondsSince1970:((TSIncomingMessage *)self).serverTimestamp.unsignedLongLongValue];
+    }
     return [NSDate ows_dateWithMillisecondsSince1970:self.receivedAtTimestamp];
 }
 
@@ -228,8 +225,8 @@ NSString *NSStringFromOWSInteractionType(OWSInteractionType value)
 
 - (uint64_t)sortId
 {
-    if ([self isKindOfClass:TSMessage.class] && ((TSMessage *)self).isOpenGroupMessage) {
-        return self.receivedAtTimestamp;
+    if ([self isKindOfClass:TSIncomingMessage.class] && ((TSIncomingMessage *)self).isOpenGroupMessage) {
+        return ((TSIncomingMessage *)self).serverTimestamp.unsignedLongLongValue;
     }
     return self.timestamp;
 }

SessionMessagingKit/Sending & Receiving/MessageReceiver.swift

@@ -145,10 +145,9 @@ public enum MessageReceiver {
             message.sender = sender
             message.recipient = userPublicKey
             message.sentTimestamp = envelope.timestamp
+            message.receivedTimestamp = NSDate.millisecondTimestamp()
             if (isOpenGroupMessage) {
-                message.receivedTimestamp = envelope.serverTimestamp
-            } else {
-                message.receivedTimestamp = NSDate.millisecondTimestamp()
+                message.openGroupServerTimestamp = envelope.serverTimestamp
             }
             message.groupPublicKey = groupPublicKey
             message.openGroupServerMessageID = openGroupMessageServerID