"""Simple JSON file cache for LLM outputs. Keyed by sha256; avoids paying twice."""
from __future__ import annotations
import json
import hashlib
import json
from pathlib import Path
from . import config

cache_dir: Path | None = None


def _dir() -> Path:
    global cache_dir
    if cache_dir is None:
        cache_dir = config.RAW_DIR / "llm_cache"
        cache_dir.mkdir(parents=True, exist_ok=True)
    return cache_dir


def llm_cache_get(key: str):
    """Return cached value or None."""
    p = _dir() / f"{key}.json"
    if not p.exists():
        return None
    try:
        return json.loads(p.read_text("utf-8"))
    except Exception:
        return None


def llm_cache_put(key: str, value) -> None:
    p = _dir() / f"{key}.json"
    try:
        p.write_text(json.dumps(value, ensure_ascii=False, default=str), "utf-8")
    except Exception:
        pass


def clear() -> None:
    global cache_dir
    if cache_dir and cache_dir.exists():
        for f in cache_dir.iterdir():
            try:
                f.unlink()
            except Exception:
                pass