src/case_zero/persistence/golden.py

"""Load sealed golden / seed case fixtures (JSON) from ``cases/seeds``.

A golden case is the FULL sealed dict: public fields + the scripted answer/delta reply
tables + the sealed solution. The public projection is taken via
``api.public_view.golden_to_public``; the scripted interrogation engine (M3) reads the
answer/delta tables directly. The returned dict is cached and must be treated as read-only.
"""

from __future__ import annotations

import json
from functools import lru_cache

from .paths import seed_case_path


@lru_cache(maxsize=8)
def load_golden(case_id: str) -> dict:
    path = seed_case_path(case_id)
    if not path.exists():
        raise FileNotFoundError(f"golden case not found: {path}")
    return json.loads(path.read_text(encoding="utf-8"))


def golden_exists(case_id: str) -> bool:
    return seed_case_path(case_id).exists()