"""Shared helpers for daemon handlers."""

from typing import Any

from daemon.server import refresh_state
from lib.sync import SyncEvent, bus


def emit_and_refresh(
    subsystem: str, payload: dict[str, Any] | None = None
) -> list[str]:
    """Emit a ``config_saved`` sync event and refresh the affected state.

    All mutation handlers end with the same tail: emit the event, refresh
    the source subsystem plus every subsystem the sync touched.

    Args:
        subsystem: Source subsystem name.
        payload: Event payload (e.g. ``{"action": "zone_created"}``).

    Returns:
        Subsystems affected by the sync event.
    """
    sync_result = bus.emit(SyncEvent(subsystem, "config_saved", payload or {}))
    refresh_state([subsystem, *sync_result.affected_subsystems])
    return sync_result.affected_subsystems