"""Run blocking work off the GTK main loop."""
from __future__ import annotations

import threading
from typing import Callable

from gi.repository import GLib


def run_async(work: Callable[[], object], done: Callable[[object, Exception | None], None]) -> None:
    """Execute `work` in a thread; call `done(result, error)` on the main loop."""
    def target():
        try:
            result, error = work(), None
        except Exception as e:  # surfaced to the UI as a toast
            result, error = None, e
        GLib.idle_add(lambda: (done(result, error), False)[1])

    threading.Thread(target=target, daemon=True).start()