"""
初始化目录监控及其后台任务。
"""

# 包根按需公开 Monitor，静态检查无法解析该惰性导出。
from app.monitor import Monitor  # pylint: disable=no-name-in-module
from app.runtime.execution import run_in_threadpool_to_completion


def init_monitor() -> None:
    """
    初始化监控器；复用单例时必须显式开启新的应用 lifespan。
    """
    monitor = Monitor.get_existing_instance()
    if monitor is None:
        Monitor()
        return
    if not monitor.lifecycle_closed:
        return
    if not monitor.reopen(timeout=Monitor.RELOAD_STOP_TIMEOUT):
        raise RuntimeError("旧目录监控 owner 未收敛，无法开启新生命周期")
    if not monitor.init(timeout=Monitor.RELOAD_STOP_TIMEOUT):
        raise RuntimeError("目录监控初始化失败")


async def stop_monitor(timeout: float = Monitor.LIFECYCLE_CLOSE_TIMEOUT) -> bool:
    """
    在线程池里永久关闭监控器，取消后仍等待同步 owner 收敛到终态。
    """
    monitor = Monitor.get_existing_instance()
    if monitor is None:
        return True
    return bool(
        await run_in_threadpool_to_completion(monitor.close, timeout=timeout)
    )