# app/state.py
from typing import Optional
from app.logging_setup import get_engine_logger

_engine_singleton = None

def set_rules_engine(engine) -> None:
    """Install the process-global rules engine."""
    global _engine_singleton
    _engine_singleton = engine
    get_engine_logger().info("[state] engine set id=%s count=%s",
                             hex(id(engine)),
                             len(getattr(engine, "rules", [])))

def get_rules_engine() -> Optional[object]:
    """Return the process-global rules engine, or None if not set yet."""
    return _engine_singleton