core, python: fix refused renames, extend the client API (#7379)

* core: do not commit refused name changes

* feat(python): add error base and missing commands

* feat(python): let callers drive startup themselves

* style(python): satisfy the linter, skip generated types

* feat(python): expose the message of a command error

* core: update query plans

* core: fix the batch limit parse error on GHC 8.10

* feat(python): reject profile images no client can render

src/Simplex/Chat/Protocol.hs

@@ -965,9 +965,10 @@ parseChatMessages msg = checkBatchLimit $ case B.head msg of
     checkBatchLimit ms
       | ms `lengthLE` maxBatchElementCount = ms
       | otherwise = [Left "too many messages in batch"]
+    -- defined prefix: GHC 8.10 does not parse a bang operand in an infix definition
     lengthLE :: [a] -> Int -> Bool
-    [] `lengthLE` !n = n >= 0
-    (_ : xs) `lengthLE` !n = n > 0 && xs `lengthLE` (n - 1)
+    lengthLE [] !n = n >= 0
+    lengthLE (_ : xs) !n = n > 0 && lengthLE xs (n - 1)
     parseUncompressed c s = case c of
       '[' -> case J.eitherDecodeStrict' s of
         Right v -> map (fmap plainMsg . parseItem) v

src/Simplex/Chat/Store/Profiles.hs

@@ -135,7 +135,6 @@ import Database.SQLite.Simple.QQ (sql)
 createUserRecordAt :: DB.Connection -> AgentUserId -> Bool -> Bool -> Profile -> Bool -> UTCTime -> ExceptT StoreError IO User
 createUserRecordAt db (AgentUserId auId) userChatRelay clientService Profile {displayName, fullName, shortDescr, description, image, peerType, preferences = userPreferences} activeUser currentTs =
   checkConstraint SEDuplicateName . liftIO $ do
-    when activeUser $ DB.execute_ db "UPDATE users SET active_user = 0"
     let showNtfs = True
         sendRcptsContacts = True
         sendRcptsSmallGroups = True
@@ -148,6 +147,9 @@ createUserRecordAt db (AgentUserId auId) userChatRelay clientService Profile {di
           :. (BI showNtfs, BI sendRcptsContacts, BI sendRcptsSmallGroups, BI autoAcceptMemberContacts, BI clientService, currentTs, currentTs)
       )
     userId <- insertedRowId db
+    -- After the insert: the name is unique in users, so a duplicate fails
+    -- above, and deactivating first would commit a database with no active user.
+    when activeUser $ DB.execute db "UPDATE users SET active_user = 0 WHERE user_id != ?" (Only userId)
     DB.execute
       db
       "INSERT INTO display_names (local_display_name, ldn_base, user_id, created_at, updated_at) VALUES (?,?,?,?,?)"
@@ -338,12 +340,14 @@ updateUserProfile db user p'
   | otherwise =
       checkConstraint SEDuplicateName . liftIO $ do
         currentTs <- getCurrentTime
-        DB.execute db "UPDATE users SET local_display_name = ?, updated_at = ? WHERE user_id = ?" (newName, currentTs, userId)
-        userMemberProfileUpdatedAt' <- updateUserMemberProfileUpdatedAt_ currentTs
+        -- Insert first: checkConstraint returns the violation as a value, so the
+        -- transaction commits, keeping whatever ran before the failing insert.
         DB.execute
           db
           "INSERT INTO display_names (local_display_name, ldn_base, user_id, created_at, updated_at) VALUES (?,?,?,?,?)"
           (newName, newName, userId, currentTs, currentTs)
+        DB.execute db "UPDATE users SET local_display_name = ?, updated_at = ? WHERE user_id = ?" (newName, currentTs, userId)
+        userMemberProfileUpdatedAt' <- updateUserMemberProfileUpdatedAt_ currentTs
         updateUserProfileFields_' db userId profileId p' currentTs
         updateContactLDN_ db user userContactId localDisplayName newName currentTs
         pure user {localDisplayName = newName, profile = (toLocalProfile profileId p' localAlias currentTs (Just False) Nothing) {localBadge}, fullPreferences, userMemberProfileUpdatedAt = userMemberProfileUpdatedAt'}

src/Simplex/Chat/Store/SQLite/Migrations/chat_query_plans.txt

@@ -7931,6 +7931,10 @@ Query: UPDATE users SET active_user = 0
 Plan:
 SCAN users
 
+Query: UPDATE users SET active_user = 0 WHERE user_id != ?
+Plan:
+SCAN users
+
 Query: UPDATE users SET active_user = 1, active_order = ? WHERE user_id = ?
 Plan:
 SEARCH users USING INTEGER PRIMARY KEY (rowid=?)