core: add chat items to indicate decryption failures due to ratchets being out of sync (#2175)

* core: add chat items to indicate decryption failures due to ratchets being out of sync

* show ratchet errors in chat items, show all integrity errors

* show decryption errors, tests

* ios: chat items, remove item for duplicate messages

* android: decryption errors chat items

* eol

src/Simplex/Chat.hs

@@ -47,6 +47,7 @@ import Data.Time (NominalDiffTime, addUTCTime, defaultTimeLocale, formatTime)
 import Data.Time.Clock (UTCTime, diffUTCTime, getCurrentTime, nominalDiffTimeToSeconds)
 import Data.Time.Clock.System (SystemTime, systemToUTCTime)
 import Data.Time.LocalTime (getCurrentTimeZone, getZonedTime)
+import Data.Word (Word32)
 import qualified Database.SQLite.Simple as DB
 import Simplex.Chat.Archive
 import Simplex.Chat.Call
@@ -2630,6 +2631,19 @@ processAgentMessageConn user@User {userId} corrId agentConnId agentMessage = do
         ERR err -> do
           toView $ CRChatError (Just user) (ChatErrorAgent err $ Just connEntity)
           when (corrId /= "") $ withCompletedCommand conn agentMsg $ \_cmdData -> pure ()
+          forM_ (agentMsgDecryptError err) $ \e@(mde, n) -> do
+            ci_ <- withStore $ \db ->
+              getDirectChatItemsLast db user contactId 1 ""
+                >>= liftIO
+                  . mapM (\(ci, content') -> updateDirectChatItem' db user contactId ci content' False Nothing)
+                  . (mdeUpdatedCI e <=< headMaybe)
+            case ci_ of
+              Just ci -> toView $ CRChatItemUpdated user (AChatItem SCTDirect SMDRcv (DirectChat ct) ci)
+              _ -> createInternalChatItem user (CDDirectRcv ct) (CIRcvDecryptionError mde n) Nothing
+          where
+            headMaybe = \case
+              x : _ -> Just x
+              _ -> Nothing
         -- TODO add debugging output
         _ -> pure ()
 
@@ -2791,9 +2805,40 @@ processAgentMessageConn user@User {userId} corrId agentConnId agentMessage = do
       ERR err -> do
         toView $ CRChatError (Just user) (ChatErrorAgent err $ Just connEntity)
         when (corrId /= "") $ withCompletedCommand conn agentMsg $ \_cmdData -> pure ()
+        forM_ (agentMsgDecryptError err) $ \e@(mde, n) -> do
+          ci_ <- withStore $ \db ->
+            getGroupMemberChatItemLast db user groupId (groupMemberId' m)
+              >>= liftIO
+                . mapM (\(ci, content') -> updateGroupChatItem db user groupId ci content' False Nothing)
+                . mdeUpdatedCI e
+          case ci_ of
+            Just ci -> toView $ CRChatItemUpdated user (AChatItem SCTGroup SMDRcv (GroupChat gInfo) ci)
+            _ -> createInternalChatItem user (CDGroupRcv gInfo m) (CIRcvDecryptionError mde n) Nothing
       -- TODO add debugging output
       _ -> pure ()
 
+    agentMsgDecryptError :: AgentErrorType -> Maybe (MsgDecryptError, Word32)
+    agentMsgDecryptError = \case
+      AGENT (A_CRYPTO RATCHET_HEADER) -> Just (MDERatchetHeader, 1)
+      AGENT (A_CRYPTO (RATCHET_EARLIER n)) -> Just (MDEEarlier, n + 1) -- 1 is added to account for the message that has A_DUPLICATE error
+      AGENT (A_CRYPTO (RATCHET_SKIPPED n)) -> Just (MDETooManySkipped, n)
+      -- we are not treating this as decryption error, as in many cases it happens as the result of duplicate or redundant delivery,
+      -- and we don't have a way to differentiate.
+      -- we could store the hashes of past messages in the agent, or delaying message deletion after ACK
+      -- A_DUPLICATE -> Nothing
+      _ -> Nothing
+
+    mdeUpdatedCI :: (MsgDecryptError, Word32) -> CChatItem c -> Maybe (ChatItem c 'MDRcv, CIContent 'MDRcv)
+    mdeUpdatedCI (mde', n') (CChatItem _ ci@ChatItem {content = CIRcvDecryptionError mde n})
+      | mde == mde' = case mde of
+        MDERatchetHeader -> r (n + n')
+        MDEEarlier -> r n -- the first error in a sequence has the largest number – it's the number of messages to receive to catch up, keeping it
+        MDETooManySkipped -> r n' -- the numbers are not added as sequential MDETooManySkipped will have it incremented by 1
+      | otherwise = Nothing
+      where
+        r n'' = Just (ci, CIRcvDecryptionError mde n'')
+    mdeUpdatedCI _ _ = Nothing
+
     processSndFileConn :: ACommand 'Agent e -> ConnectionEntity -> Connection -> SndFileTransfer -> m ()
     processSndFileConn agentMsg connEntity conn ft@SndFileTransfer {fileId, fileName, fileStatus} =
       case agentMsg of
@@ -3469,9 +3514,7 @@ processAgentMessageConn user@User {userId} corrId agentConnId agentMessage = do
     checkIntegrityCreateItem :: forall c. ChatTypeI c => ChatDirection c 'MDRcv -> MsgMeta -> m ()
     checkIntegrityCreateItem cd MsgMeta {integrity, broker = (_, brokerTs)} = case integrity of
       MsgOk -> pure ()
-      MsgError e -> case e of
-        MsgSkipped {} -> createInternalChatItem user cd (CIRcvIntegrityError e) (Just brokerTs)
-        _ -> toView $ CRMsgIntegrityError user e
+      MsgError e -> createInternalChatItem user cd (CIRcvIntegrityError e) (Just brokerTs)
 
     xInfo :: Contact -> Profile -> m ()
     xInfo c@Contact {profile = p} p' = unless (fromLocalProfile p == p') $ do