"""Sub-second exit management on a dedicated daemon thread (plan 018).

Exits used to run as a step on the single-threaded main scheduler, so real
reaction drifted past the interval whenever a slower step (ingest, discover,
news) held the thread. On a $2-20 small-cap that round-trips in seconds, that
gave back gains. This runs LiveExitManager.manage() on its OWN thread, at a
~1s cadence, independent of the scheduler queue — the symmetric twin of the
fast trigger thread that already handles entries.

Two invariants make this safe (audited 2026-07-19):
  * SINGLE CALLER — the scheduler's "exits" step is removed when the thread
    runs, so manage() is invoked from exactly one thread; its mutable instance
    state (_tracked / _naked_passes / _empty_snapshot_streak) never races.
  * IDEMPOTENT manage() — the stop ratchet only replaces when the desired stop
    is >1c ABOVE the resting one (exit_manager.py), so a 1s cadence re-submits
    nothing once a level is set; catastrophe/scale close the position, so the
    next pass sees it gone. The manager must also get its OWN research DB
    connection for bars (the shared facade connection is not thread-safe).
"""

from __future__ import annotations

import logging
from typing import Callable

logger = logging.getLogger(__name__)


def run_exit_loop(exit_mgr, stop_event, interval: float = 1.0,
                  on_error: Callable[[Exception], None] | None = None) -> None:
    """Drive ``exit_mgr.manage()`` every ``interval`` seconds until
    ``stop_event`` is set. Mirrors ``trigger_loop``: waits FIRST (so a
    pre-set stop returns immediately without a manage call), and a manage()
    exception is caught — a live exit loop must never die on a broker blip and
    leave positions unmanaged."""
    while not stop_event.wait(interval):
        try:
            exit_mgr.manage()
        except Exception as exc:  # noqa: BLE001 — one bad pass must not kill exits
            if on_error is not None:
                on_error(exc)
            else:
                logger.warning("exit pass failed (continuing): %s", exc)