core: remove Hello from the app remote protocol (#3336)

src/Simplex/Chat/Remote.hs

@@ -141,18 +141,21 @@ startRemoteHost' rh_ = do
     mkCtrlAppInfo = do
       deviceName <- chatReadVar localDeviceName
       pure CtrlAppInfo {appVersionRange = ctrlAppVersionRange, deviceName}
-    parseHostAppInfo RCHostHello {app = hostAppInfo} rhKey = do
-      HostAppInfo {deviceName, appVersion} <-
-        liftEitherWith (ChatErrorRemoteHost rhKey . RHEProtocolError . RPEInvalidJSON) $ JT.parseEither J.parseJSON hostAppInfo
-      unless (isAppCompatible appVersion ctrlAppVersionRange) $ throwError $ ChatErrorRemoteHost rhKey $ RHEBadVersion appVersion
-      pure deviceName
+    parseHostAppInfo :: RCHostHello -> ExceptT RemoteHostError IO HostAppInfo
+    parseHostAppInfo RCHostHello {app = hostAppInfo} = do
+      hostInfo@HostAppInfo {deviceName, appVersion, encoding, encryptFiles} <-
+        liftEitherWith (RHEProtocolError . RPEInvalidJSON) $ JT.parseEither J.parseJSON hostAppInfo
+      unless (isAppCompatible appVersion ctrlAppVersionRange) $ throwError $ RHEBadVersion appVersion
+      when (encoding == PEKotlin && localEncoding == PESwift) $ throwError $ RHEProtocolError RPEIncompatibleEncoding
+      pure hostInfo
     waitForSession :: ChatMonad m => RHKey -> Maybe RemoteHostInfo -> RCHostClient -> RCStepTMVar (ByteString, RCStepTMVar (RCHostSession, RCHostHello, RCHostPairing)) -> m ()
     waitForSession rhKey remoteHost_ _rchClient_kill_on_error vars = do
       -- TODO handle errors
       (sessId, vars') <- takeRCStep vars
       toView $ CRRemoteHostSessionCode {remoteHost_, sessionCode = verificationCode sessId} -- display confirmation code, wait for mobile to confirm
       (RCHostSession {tls, sessionKeys}, rhHello, pairing') <- takeRCStep vars'
-      hostDeviceName <- parseHostAppInfo rhHello rhKey
+      hostInfo@HostAppInfo {deviceName = hostDeviceName} <-
+        liftError (ChatErrorRemoteHost rhKey) $ parseHostAppInfo rhHello
       withRemoteHostSession rhKey $ \case
         RHSessionConnecting rhs' -> Right ((), RHSessionConfirmed rhs') -- TODO check it's the same session?
         _ -> Left $ ChatErrorRemoteHost rhKey RHEBadState -- TODO kill client on error
@@ -161,7 +164,7 @@ startRemoteHost' rh_ = do
       let rhKey' = RHId remoteHostId
       disconnected <- toIO $ onDisconnected remoteHostId
       httpClient <- liftEitherError (httpError rhKey) $ attachRevHTTP2Client disconnected tls
-      rhClient <- liftRC $ createRemoteHostClient httpClient sessionKeys storePath hostDeviceName
+      let rhClient = mkRemoteHostClient httpClient sessionKeys storePath hostInfo
       pollAction <- async $ pollEvents remoteHostId rhClient
       withRemoteHostSession rhKey' $ \case
         RHSessionConfirmed RHPendingSession {} -> Right ((), RHSessionConnected {rhClient, pollAction, storePath})
@@ -346,7 +349,6 @@ handleRemoteCommand execChatCommand _sessionKeys remoteOutputQ HTTP2Request {req
     replyError = reply . RRChatResponse . CRChatCmdError Nothing
     processCommand :: User -> GetChunk -> RemoteCommand -> m ()
     processCommand user getNext = \case
-      RCHello {deviceName = desktopName} -> handleHello desktopName >>= reply
       RCSend {command} -> handleSend execChatCommand command >>= reply
       RCRecv {wait = time} -> handleRecv time remoteOutputQ >>= reply
       RCStoreFile {fileName, fileSize, fileDigest} -> handleStoreFile fileName fileSize fileDigest getNext >>= reply
@@ -376,13 +378,6 @@ tryRemoteError :: ExceptT RemoteProtocolError IO a -> ExceptT RemoteProtocolErro
 tryRemoteError = tryAllErrors (RPEException . tshow)
 {-# INLINE tryRemoteError #-}
 
-handleHello :: ChatMonad m => Text -> m RemoteResponse
-handleHello desktopName = do
-  logInfo $ "Hello from " <> tshow desktopName
-  mobileName <- chatReadVar localDeviceName
-  encryptFiles <- chatReadVar encryptLocalFiles
-  pure RRHello {encoding = localEncoding, deviceName = mobileName, encryptFiles}
-
 handleSend :: ChatMonad m => (ByteString -> m ChatResponse) -> Text -> m RemoteResponse
 handleSend execChatCommand command = do
   logDebug $ "Send: " <> tshow command

src/Simplex/Chat/Remote/Protocol.hs

@@ -9,7 +9,6 @@
 
 module Simplex.Chat.Remote.Protocol where
 
-import Control.Logger.Simple
 import Control.Monad
 import Control.Monad.Except
 import Data.Aeson ((.=))
@@ -44,8 +43,7 @@ import System.FilePath (takeFileName, (</>))
 import UnliftIO
 
 data RemoteCommand
-  = RCHello {deviceName :: Text}
-  | RCSend {command :: Text} -- TODO maybe ChatCommand here?
+  = RCSend {command :: Text} -- TODO maybe ChatCommand here?
   | RCRecv {wait :: Int} -- this wait should be less than HTTP timeout
   | -- local file encryption is determined by the host, but can be overridden for videos
     RCStoreFile {fileName :: String, fileSize :: Word32, fileDigest :: FileDigest} -- requires attachment
@@ -53,8 +51,7 @@ data RemoteCommand
   deriving (Show)
 
 data RemoteResponse
-  = RRHello {encoding :: PlatformEncoding, deviceName :: Text, encryptFiles :: Bool}
-  | RRChatResponse {chatResponse :: ChatResponse}
+  = RRChatResponse {chatResponse :: ChatResponse}
   | RRChatEvent {chatEvent :: Maybe ChatResponse} -- ^ 'Nothing' on poll timeout
   | RRFileStored {filePath :: String}
   | RRFile {fileSize :: Word32, fileDigest :: FileDigest} -- provides attachment , fileDigest :: FileDigest
@@ -67,22 +64,16 @@ $(deriveJSON (taggedObjectJSON $ dropPrefix "RR") ''RemoteResponse)
 
 -- * Client side / desktop
 
-createRemoteHostClient :: HTTP2Client -> HostSessKeys -> FilePath -> Text -> ExceptT RemoteProtocolError IO RemoteHostClient
-createRemoteHostClient httpClient sessionKeys storePath desktopName = do
-  logDebug "Sending initial hello"
-  sendRemoteCommand' httpClient localEncoding Nothing RCHello {deviceName = desktopName} >>= \case
-    RRHello {encoding, deviceName = mobileName, encryptFiles} -> do
-      logDebug "Got initial hello"
-      when (encoding == PEKotlin && localEncoding == PESwift) $ throwError RPEIncompatibleEncoding
-      pure RemoteHostClient
-        { hostEncoding = encoding,
-          hostDeviceName = mobileName,
-          httpClient,
-          encryptHostFiles = encryptFiles,
-          sessionKeys,
-          storePath
-        }
-    r -> badResponse r
+mkRemoteHostClient :: HTTP2Client -> HostSessKeys -> FilePath -> HostAppInfo -> RemoteHostClient
+mkRemoteHostClient httpClient sessionKeys storePath HostAppInfo {encoding, deviceName, encryptFiles} =
+  RemoteHostClient
+    { hostEncoding = encoding,
+      hostDeviceName = deviceName,
+      httpClient,
+      encryptHostFiles = encryptFiles,
+      sessionKeys,
+      storePath
+    }
 
 closeRemoteHostClient :: MonadIO m => RemoteHostClient -> m ()
 closeRemoteHostClient RemoteHostClient {httpClient} = liftIO $ closeHTTP2Client httpClient
@@ -148,7 +139,7 @@ convertJSON :: PlatformEncoding -> PlatformEncoding -> J.Value -> J.Value
 convertJSON _remote@PEKotlin _local@PEKotlin = id
 convertJSON PESwift PESwift = id
 convertJSON PESwift PEKotlin = owsf2tagged
-convertJSON PEKotlin PESwift = error "unsupported convertJSON: K/S" -- guarded by createRemoteHostClient
+convertJSON PEKotlin PESwift = error "unsupported convertJSON: K/S" -- guarded by handshake
 
 -- | Convert swift single-field sum encoding into tagged/discriminator-field
 owsf2tagged :: J.Value -> J.Value