import json

from pathlib import Path

class Cache:

def __init__(self, root: str | Path):

self._root = Path(root)

self._cache_file = self._root / ".codetree" / "index.json"

self._data: dict = {}

def load(self):

"""Load cache from disk. No-op if cache file doesn't exist or is corrupt."""

if self._cache_file.exists():

try:

self._data = json.loads(self._cache_file.read_text())

except (json.JSONDecodeError, OSError):

self._data = {}

def save(self):

"""Write cache to disk, creating .codetree/ directory if needed."""

self._cache_file.parent.mkdir(parents=True, exist_ok=True)

self._cache_file.write_text(json.dumps(self._data, indent=2))

def get(self, rel_path: str) -> dict | None:

return self._data.get(rel_path)

def set(self, rel_path: str, data: dict):

self._data[rel_path] = data

def is_valid(self, rel_path: str, current_mtime: float) -> bool:

"""Return True if cached entry exists and mtime matches current_mtime."""

entry = self._data.get(rel_path)

if entry is None:

return False

return entry.get("mtime") == current_mtime