"""Execute the real entrypoint with a private TCP binding and graceful test shutdown.

Only asyncio.start_server's binding arguments are redirected. Its real server,
TCP.run, handler, manager, router, protocol and background sends all run normally.
The stdin task cancels main just as an external stop would, allowing coverage's
atexit hook to save child measurements on Windows as well as Linux.
"""

import asyncio
from pathlib import Path
import runpy
import sys


async def stop_from_stdin(main_task):
    await asyncio.to_thread(sys.stdin.buffer.readline)
    main_task.cancel()


def run():
    main = Path(sys.argv[1]).resolve()
    original_start_server = asyncio.start_server

    async def start_server(callback, host=None, port=None, **kwargs):
        server = await original_start_server(callback, "127.0.0.1", 0, **kwargs)
        address = server.sockets[0].getsockname()
        asyncio.create_task(stop_from_stdin(asyncio.current_task()))
        print(f"TCP listening {address[0]}:{address[1]}", flush=True)
        return server

    asyncio.start_server = start_server
    sys.path.insert(0, str(main.parent))
    sys.argv = [str(main)]
    try:
        runpy.run_path(str(main), run_name="__main__")
    except asyncio.CancelledError:
        pass


if __name__ == "__main__":
    run()