TODO: ask peer its role

src/server.py

@@ -86,8 +86,9 @@ class Server:
 
         Decide whether client is sender or receiver and start transmission.
         """
-        if not self.working:
-            self._working = True
+        peer_is_sender = not self.working  # TODO: ask peer role
+        self._working = True
+        if peer_is_sender:
             logging.info("Sender is connecting...")
             await self.run_reader(reader=reader)
             logging.info("Incoming transmission ended")