"""Authorization management for device access control."""
import json
import os
from pathlib import Path
from typing import Set


class AuthorizationManager:
    """Manages device authorization with hot-reload capability."""

    def __init__(self, file_path: str):
        """Initialize authorization manager with file path.

        Args:
            file_path: Path to the authorized_devices.json file
        """
        self.file_path = Path(file_path)
        self._authorized_devices: Set[str] = set()
        self._last_modified: float = 0.0
        self._load_authorization_list()

    def _load_authorization_list(self) -> None:
        """Load authorization list from JSON file."""
        try:
            if not self.file_path.exists():
                self._authorized_devices = set()
                self._last_modified = 0.0
                return

            stat = os.stat(self.file_path)
            self._last_modified = stat.st_mtime

            with open(self.file_path, "r") as f:
                data = json.load(f)
                self._authorized_devices = set(data.get("authorized_devices", []))

        except (json.JSONDecodeError, OSError) as e:
            self._authorized_devices = set()
            self._last_modified = 0.0

    def _check_reload(self) -> None:
        """Check if authorization file has been modified and reload if necessary."""
        try:
            if not self.file_path.exists():
                if self._last_modified != 0.0:
                    self._authorized_devices = set()
                    self._last_modified = 0.0
                return

            stat = os.stat(self.file_path)
            if stat.st_mtime > self._last_modified:
                self._load_authorization_list()

        except OSError:
            pass

    def is_authorized(self, device_id: str) -> bool:
        """Check if a device ID is authorized.

        Args:
            device_id: The device identifier to check

        Returns:
            True if authorized, False otherwise
        """
        self._check_reload()
        return device_id in self._authorized_devices