from __future__ import annotations

from collections.abc import AsyncIterator
from signal import Signals
from typing import ContextManager

from ._eventloop import get_async_backend


def open_signal_receiver(*signals: Signals) -> ContextManager[AsyncIterator[Signals]]:
    """
    Start receiving operating system signals.

    :param signals: signals to receive (e.g. ``signal.SIGINT``)
    :return: an asynchronous context manager for an asynchronous iterator which yields
        signal numbers

    .. warning:: Windows does not support signals natively so it is best to avoid
        relying on this in cross-platform applications.

    .. warning:: On asyncio, this permanently replaces any previous signal handler for
        the given signals, as set via :meth:`~asyncio.loop.add_signal_handler`.

    """
    return get_async_backend().open_signal_receiver(*signals)