Add network status/latency info

desktop-client/sync_client.py

@@ -1,5 +1,6 @@
 import asyncio
 import json
+import time
 import websockets
 from PyQt6.QtCore import QThread, pyqtSignal
 
@@ -15,6 +16,7 @@ class SyncClientThread(QThread):
     chat_message = pyqtSignal(str, str, int) # author, text, timestamp
     system_message = pyqtSignal(str)
     sync_event = pyqtSignal(dict)
+    latency_updated = pyqtSignal(int) # latency in ms
 
     def __init__(self, url="ws://localhost:3000/ws"):
         super().__init__()
@@ -22,6 +24,7 @@ class SyncClientThread(QThread):
         self.ws = None
         self.loop = None
         self.running = False
+        self._ping_sent_at = 0
 
     def run(self):
         """Runs strictly within the newly created QThread"""
@@ -44,6 +47,19 @@ class SyncClientThread(QThread):
             json_str = json.dumps(message)
             asyncio.run_coroutine_threadsafe(self.ws.send(json_str), self.loop)
 
+    async def _ping_loop(self, ws):
+        """Sends WebSocket protocol-level pings every 5s to measure latency."""
+        while self.running:
+            try:
+                pong = await ws.ping()
+                sent_at = time.time()
+                await asyncio.wait_for(pong, timeout=5)
+                latency_ms = int((time.time() - sent_at) * 1000)
+                self.latency_updated.emit(latency_ms)
+            except Exception:
+                break
+            await asyncio.sleep(5)
+
     async def _connect_and_listen(self):
         while self.running:
             try:
@@ -51,6 +67,7 @@ class SyncClientThread(QThread):
                     self.ws = ws
                     self.connected.emit()
                     
+                    ping_task = asyncio.create_task(self._ping_loop(ws))
                     try:
                         async for message in ws:
                             if not self.running:
@@ -58,6 +75,8 @@ class SyncClientThread(QThread):
                             self._handle_message(json.loads(message))
                     except websockets.ConnectionClosed:
                         pass
+                    finally:
+                        ping_task.cancel()
                         
             except Exception as e:
                 print(f"WebSocket Error: {e}")