from __future__ import annotations

import hashlib
import json
from pathlib import Path
from typing import Any


def make_key(prefix: str, identifier: str) -> str:
    """Stable, collision-safe state key from prefix + arbitrary identifier."""
    h = hashlib.md5(identifier.encode()).hexdigest()[:8]
    return f"{prefix}_{h}"


class State:
    def __init__(self, path: str) -> None:
        self._path = Path(path)
        self._path.parent.mkdir(parents=True, exist_ok=True)
        self._data: dict[str, Any] = {}
        self._load()

    def _load(self) -> None:
        if self._path.exists():
            try:
                self._data = json.loads(self._path.read_text())
            except (json.JSONDecodeError, OSError):
                self._data = {}

    def _save(self) -> None:
        self._path.write_text(json.dumps(self._data, indent=2))

    def get(self, key: str, default: Any = None) -> Any:
        return self._data.get(key, default)

    def set(self, key: str, value: Any) -> None:
        self._data[key] = value
        self._save()

    def delete(self, *keys: str) -> None:
        changed = any(k in self._data for k in keys)
        for k in keys:
            self._data.pop(k, None)
        if changed:
            self._save()