#!/usr/bin/env python
"""Launcher: runs the Django ASGI server locally and opens it in a native window."""

import os
import sys
import threading
import time

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "backend.settings")

# Qt WebEngine crashes on some GPU/driver combinations unless it renders on CPU.
os.environ.setdefault("QTWEBENGINE_CHROMIUM_FLAGS", "--disable-gpu")


def start_server(host: str, port: int):
    import django

    django.setup()

    from django.core.management import call_command

    # --run-syncdb builds the tables on a first launch with no migration files.
    call_command("migrate", "--run-syncdb", verbosity=0)

    import uvicorn

    uvicorn.run(
        "backend.asgi:application",
        host=host,
        port=port,
        log_level="warning",
    )


def wait_for_server(url: str, timeout: float = 10.0) -> None:
    """Poll until the server answers, or raise carrying the last refusal."""
    from urllib.request import urlopen

    deadline = time.time() + timeout
    last_error: OSError | None = None
    while time.time() < deadline:
        try:
            urlopen(url, timeout=1)
            return
        except OSError as e:
            last_error = e
            time.sleep(0.1)

    raise TimeoutError(
        f"Django server did not answer {url} within {timeout}s"
    ) from last_error


def main():
    host = "127.0.0.1"
    port = 8765

    server = threading.Thread(target=start_server, args=(host, port), daemon=True)
    server.start()

    base_url = f"http://{host}:{port}"
    wait_for_server(f"{base_url}/api/mizan/session/")

    print(f"Backend running at {base_url}")

    if "--headless" in sys.argv:
        print("Headless mode — server running. Press Ctrl+C to stop.")
        try:
            while True:
                time.sleep(1)
        except KeyboardInterrupt:
            print("Interrupted — stopping the server.", file=sys.stderr)
        return

    import webview

    webview.create_window(
        title="mizan Desktop",
        url=base_url,
        width=1024,
        height=768,
        min_size=(640, 480),
    )
    webview.start()


if __name__ == "__main__":
    main()