import json, hashlib
from pathlib import Path


class DiskCache:
    def __init__(self, cache_dir: str = ".cache"):
        self.cache_dir = Path(cache_dir)
        self.cache_dir.mkdir(parents=True, exist_ok=True)

    def _key_path(self, key: str) -> Path:
        h = hashlib.sha256(key.encode()).hexdigest()
        return self.cache_dir / f"{h}.json"

    def get(self, key: str):
        path = self._key_path(key)
        if path.exists():
            return json.loads(path.read_text())
        return None

    def set(self, key: str, value):
        self._key_path(key).write_text(json.dumps(value))

    def invalidate(self, key: str):
        p = self._key_path(key)
        if p.exists():
            p.unlink()


class ReportStore:
    def __init__(self, base_dir: str = "./reports"):
        self.base_dir = Path(base_dir)

    def save_history(self, program: str, status: str, matched: int, duration: float):
        trend = self.base_dir / "trends" / f"{program}.jsonl"
        trend.parent.mkdir(parents=True, exist_ok=True)
        import datetime
        entry = {"ts": datetime.datetime.now().isoformat(), "status": status,
                 "fields_matched": matched, "duration_s": duration}
        with open(trend, "a") as f:
            f.write(json.dumps(entry) + "\n")