"""Exclusive pipeline pause held until a synchronous or asynchronous operation ends."""

from __future__ import annotations

from collections.abc import Callable


class PipelinePause:
    """Suspend acquisition and restart intent; an explicit Stop cancels resumption."""

    def __init__(self, valid: Callable[[], bool], release: Callable[[bool], None]) -> None:
        self._valid = valid
        self._release = release
        self._finished = False

    @property
    def valid(self) -> bool:
        return not self._finished and self._valid()

    def finish(self, *, resume: bool = True) -> None:
        if self._finished:
            return
        should_resume = resume and self.valid
        self._finished = True
        self._release(should_resume)

    def __enter__(self) -> PipelinePause:
        return self

    def __exit__(self, *_exc: object) -> None:
        self.finish()