add debug logs for on air reconnects (#3679)

* add debug logs for on air reconnects

* also disconnect from streams

* less frequent messages

nicegui/air.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 import asyncio
 import gzip
 import json
+import logging
 import re
 from dataclasses import dataclass
 from typing import TYPE_CHECKING, Any, AsyncIterator, Dict, Optional
@@ -34,6 +35,7 @@ class Air:
     def __init__(self, token: str) -> None:
         import httpx  # pylint: disable=import-outside-toplevel
 
+        self.log = logging.getLogger('nicegui.air')
         self.token = token
         self.relay = socketio.AsyncClient()
         self.client = httpx.AsyncClient(app=core.app)
@@ -172,28 +174,35 @@ class Air:
 
     async def connect(self) -> None:
         """Connect to the NiceGUI On Air server."""
-        if self.connecting or self.relay.connected:
+        if self.connecting:
+            self.log.debug('Already connecting.')
             return
+        if self.relay.connected:
+            return
+        self.log.debug('Going to connect...')
         self.connecting = True
         backoff_time = 1
         try:
             while True:
                 try:
                     if self.relay.connected:
-                        await self.relay.disconnect()
+                        await asyncio.wait_for(self.disconnect(), timeout=5)
+                    self.log.debug('Connecting...')
                     await self.relay.connect(
                         f'{RELAY_HOST}?device_token={self.token}',
                         socketio_path='/on_air/socket.io',
                         transports=['websocket', 'polling'],  # favor websocket over polling
                     )
+                    self.log.debug('Connected.')
                     break
                 except socketio.exceptions.ConnectionError:
-                    pass
+                    self.log.debug('Connection error.', stack_info=True)
                 except ValueError:  # NOTE this sometimes happens when the internal socketio client is not yet ready
-                    pass
+                    self.log.debug('ValueError while connecting.', stack_info=True)
                 except Exception:
                     log.exception('Could not connect to NiceGUI On Air server.')
 
+                self.log.debug(f'Retrying in {backoff_time} seconds...')
                 await asyncio.sleep(backoff_time)
                 backoff_time = min(backoff_time * 2, 32)
         finally:
@@ -201,11 +210,13 @@ class Air:
 
     async def disconnect(self) -> None:
         """Disconnect from the NiceGUI On Air server."""
+        self.log.debug('Disconnecting...')
         if self.relay.connected:
             await self.relay.disconnect()
         for stream in self.streams.values():
             await stream.response.aclose()
         self.streams.clear()
+        self.log.debug('Disconnected.')
 
     async def emit(self, message_type: str, data: Dict[str, Any], room: str) -> None:
         """Emit a message to the NiceGUI On Air server."""