import sys

IS_WINDOWS: bool = sys.platform == "win32"

if IS_WINDOWS:
    import win32api
else:
    import signal


class WhileStopper:

    is_registered: bool
    stop_requested: bool

    def __init__(self) -> None:
        self.is_registered = False
        self.stop_requested = False

    def is_stop_requested(self) -> bool:
        if not self.is_registered:
            raise RuntimeError('unexpected stopper status')

        return self.stop_requested

    def register(self):
        if self.is_registered:
            raise RuntimeError('unexpected stopper status')

        self.stop_requested = False
        if IS_WINDOWS:
            win32api.SetConsoleCtrlHandler(self.__win_handler, True)
        else:
            signal.signal(signal.SIGINT, self.__posix_handler)
        self.is_registered = True

    def unregister(self):
        if not self.is_registered:
            raise RuntimeError('unexpected stopper status')

        if IS_WINDOWS:
            win32api.SetConsoleCtrlHandler(None, False)
        else:
            signal.signal(signal.SIGINT, signal.SIG_DFL)
        self.is_registered = False

    def __win_handler(self, ctrl_type: int) -> bool:
        self.stop_requested = True
        return True

    def __posix_handler(self, signal, frame) -> None:
        self.stop_requested = True