server shutdown ws message (#179)

* shutdown change

* fix

Author: mihaimarcu2004

lighter/ws_client.py

@@ -3,6 +3,8 @@
 from websockets.client import connect as connect_async
 from lighter.configuration import Configuration
 from lighter.endpoint_profiles import join_url
+import logging
+logger = logging.getLogger(__name__)
 
 class WsClient:
     def __init__(
@@ -14,6 +16,8 @@ def __init__(
         on_order_book_update=print,
         on_account_update=print,
         ws_url=None,
+        on_shutdown=None,
+        on_unhandled_message=None,
     ):
         if ws_url is not None:
             self.base_url = ws_url.rstrip("/")
@@ -35,6 +39,8 @@ def __init__(
 
         self.on_order_book_update = on_order_book_update
         self.on_account_update = on_account_update
+        self.on_shutdown = on_shutdown
+        self.on_unhandled_message = on_unhandled_message
 
         self.ws = None
 
@@ -57,6 +63,8 @@ def on_message(self, ws, message):
         elif message_type == "ping":
             # Respond to ping with pong
             ws.send(json.dumps({"type": "pong"}))
+        elif message_type == "shutdown":
+            self.handle_shutdown(message)
         else:
             self.handle_unhandled_message(message)
 
@@ -149,7 +157,17 @@ def handle_update_account(self, message):
             self.on_account_update(account_id, self.account_states[account_id])
 
     def handle_unhandled_message(self, message):
-        raise Exception(f"Unhandled message: {message}")
+        if self.on_unhandled_message:
+            self.on_unhandled_message(message)
+        else:
+            logger.warning("Unhandled message type %r: %s", message.get("type"), message)
+
+    def handle_shutdown(self, message):
+        close_in_ms = message.get("close_in_ms", 0)
+        if self.on_shutdown:
+            self.on_shutdown(close_in_ms)
+        else:
+            print(f"Server shutting down, connection closes in {close_in_ms}ms")
 
     def on_error(self, ws, error):
         raise Exception(f"Error: {error}")