from __future__ import annotations

from pathlib import Path
from uuid import UUID

from .commands.cryptsetup import Cryptsetup
from .misc import DISK_BY_UUID


class Disk:
    def __init__(self, uuid: UUID, name: str):
        self.uuid = uuid
        self._decrypted: bool = False
        self._was_already_decrypted: bool = False
        self._name = name

    def decrypt(self) -> None:
        """Open a LUKS-encrypted disk with `cryptsetup`. Silently pass if it was already decrypted."""
        if self._decrypted:
            raise ValueError("Cannot decrypt, already decrypted", self._name)
        self._was_already_decrypted = Cryptsetup.decrypt(self._path, self._mapper_entry)
        self._decrypted = True

    @property
    def _path(self) -> Path:
        """Unique path of the disk using /dev/disk/by-uuid."""
        return DISK_BY_UUID / str(self.uuid)

    @property
    def _mapper_entry(self) -> str:
        """Name under which the decrypted disk will appear in /dev/mapper."""
        return f"crypt-{self._name}"

    def encrypt(self) -> None:
        """Close a LUKS-encrypted container with `cryptsetup`."""
        if not self._decrypted:
            raise ValueError("Cannot encrypt, not decrypted", self._name)
        if self._was_already_decrypted:
            return
        Cryptsetup.encrypt(self._mapper_entry)
        self._decrypted = False