send files to contacts (#94)

* schema for sending files

* send file "invitation"

* receive file "invitation"

* send/receive file flow (with stubs)

* update simplexmq

* send and receive the file (WIP - only the first chunk)

* sending and receiving file works (but it is slow)

* use correct terminal output for file sending/receiving

* improve file transfer, support cancellation

* command to show file transfer status and progress

* file transfer tests

* resume file transfer on restart (WIP)

* stabilize test of recipient cancelling file transfer

* trying to improve file transfer on restart

* update SMP block size and file chunk size

* acquire agent lock before chat lock to test whether it avoids deadlock

* fix resuming sending file on client restart

* manual message ACK (prevents losing messages between agent and chat client and stabilizes resuming file reception after restart)

* do NOT send file chunk after receiving it before it is appended to the file

* update file chunk size for SMP block size 8192 (set in smpDefaultConfig)

* save received files to ~/Downloads folder by default; create empty file when file is accepted

* keep file handle used to create empty file

* check message integrity

* fix trying to resume sending file when it was not yet accepted

* fix subscribing to pending connections on start

* update simplexmq (fixes smp-server syntax parser)

src/Simplex/Chat/Controller.hs

@@ -11,15 +11,27 @@ import Control.Monad.Except
 import Control.Monad.IO.Unlift
 import Control.Monad.Reader
 import Crypto.Random (ChaChaDRG)
+import Data.Int (Int64)
+import Data.Map.Strict (Map)
+import Numeric.Natural
 import Simplex.Chat.Notification
 import Simplex.Chat.Store (StoreError)
 import Simplex.Chat.Terminal
 import Simplex.Chat.Types
 import Simplex.Messaging.Agent (AgentClient)
+import Simplex.Messaging.Agent.Env.SQLite (AgentConfig)
 import Simplex.Messaging.Agent.Protocol (AgentErrorType)
 import Simplex.Messaging.Agent.Store.SQLite (SQLiteStore)
+import System.IO (Handle)
 import UnliftIO.STM
 
+data ChatConfig = ChatConfig
+  { agentConfig :: AgentConfig,
+    dbPoolSize :: Int,
+    tbqSize :: Natural,
+    fileChunkSize :: Integer
+  }
+
 data ChatController = ChatController
   { currentUser :: TVar User,
     smpAgent :: AgentClient,
@@ -29,7 +41,10 @@ data ChatController = ChatController
     inputQ :: TBQueue InputEvent,
     notifyQ :: TBQueue Notification,
     sendNotification :: Notification -> IO (),
-    chatLock :: TMVar ()
+    chatLock :: TMVar (),
+    sndFiles :: TVar (Map Int64 Handle),
+    rcvFiles :: TVar (Map Int64 Handle),
+    config :: ChatConfig
   }
 
 data InputEvent = InputCommand String | InputControl Char
@@ -51,6 +66,14 @@ data ChatErrorType
   | CEGroupMemberUserRemoved
   | CEGroupMemberNotFound ContactName
   | CEGroupInternal String
+  | CEFileNotFound String
+  | CEFileAlreadyReceiving String
+  | CEFileAlreadyExists FilePath
+  | CEFileRead FilePath SomeException
+  | CEFileWrite FilePath SomeException
+  | CEFileSend Int64 AgentErrorType
+  | CEFileRcvChunk String
+  | CEFileInternal String
   deriving (Show, Exception)
 
 type ChatMonad m = (MonadUnliftIO m, MonadReader ChatController m, MonadError ChatError m)