"""Run-lifecycle hooks: plugins that observe/extend a run without touching
its logic. Register with @register_hook('on_benchmark_failed') etc.; the CLI
fires them at the matching points. Multiple hooks per event all run.

    from evalharness.hooks import register_hook

    @register_hook('on_benchmark_failed')
    def notify(name, error, **ctx):
        requests.post(webhook, json={'bench': name, 'error': str(error)})
"""
from typing import Callable, Dict, List

_HOOKS: Dict[str, List[Callable]] = {}


def register_hook(event: str):
    def decorator(fn):
        _HOOKS.setdefault(event, []).append(fn)
        return fn

    return decorator


def fire(event: str, **ctx) -> None:
    """Invoke every hook registered for the event; hook errors are printed
    and swallowed -- observability must never break the run."""
    for fn in _HOOKS.get(event, []):
        try:
            fn(**ctx)
        except Exception as e:
            print(f'hook {fn.__name__!r} failed: {type(e).__name__}: {e}', flush=True)