"""
backend/asgi.py
================
ASGI application entrypoint for Fashionistar.

HTTP requests stay on Django's standard ASGI app. WebSocket traffic is routed
through the modular app registry with JWT query-string authentication.

Settings module priority:
  1. DJANGO_SETTINGS_MODULE environment variable (set by Dockerfile in prod).
  2. Falls back to development settings for local ``uvicorn backend.asgi:application``.
"""

import os

from channels.routing import ProtocolTypeRouter, URLRouter
from django.core.asgi import get_asgi_application

# setdefault only fires when DJANGO_SETTINGS_MODULE is NOT already in the
# environment.  The production Dockerfile sets it to backend.config.production,
# so this default only applies to local development runs.
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "backend.config.development")

django_asgi_app = get_asgi_application()

from backend.websocket_auth import JWTQueryAuthMiddleware  # noqa: E402
from backend.websocket_routes import websocket_urlpatterns  # noqa: E402


class LifespanASGIWrapper:
    """
    Wrap an ASGI app to handle the 'lifespan' protocol.

    Django's default ASGI handler does not implement lifespan, causing
    Uvicorn to emit: "WARNING:  ASGI 'lifespan' format appears unsupported."
    This wrapper silently accepts lifespan startup/shutdown messages.
    """

    def __init__(self, app):
        self.app = app

    async def __call__(self, scope, receive, send):
        if scope["type"] == "lifespan":
            while True:
                message = await receive()
                if message["type"] == "lifespan.startup":
                    await send({"type": "lifespan.startup.complete"})
                elif message["type"] == "lifespan.shutdown":
                    await send({"type": "lifespan.shutdown.complete"})
                    return
        else:
            await self.app(scope, receive, send)


application = LifespanASGIWrapper(
    ProtocolTypeRouter(
        {
            "http": django_asgi_app,
            "websocket": JWTQueryAuthMiddleware(URLRouter(websocket_urlpatterns)),
        }
    )
)