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#
#   http://www.apache.org/licenses/LICENSE-2.0
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from abc import ABCMeta
from abc import abstractmethod
from pathlib import Path
from typing import Optional

from selenium.types import AnyKey
from selenium.webdriver.common.utils import keys_to_typing


class FileDetector(metaclass=ABCMeta):
    """Used for identifying whether a sequence of chars represents the path to
    a file."""

    @abstractmethod
    def is_local_file(self, *keys: AnyKey) -> Optional[str]:
        raise NotImplementedError


class UselessFileDetector(FileDetector):
    """A file detector that never finds anything."""

    def is_local_file(self, *keys: AnyKey) -> Optional[str]:
        return None


class LocalFileDetector(FileDetector):
    """Detects files on the local disk."""

    def is_local_file(self, *keys: AnyKey) -> Optional[str]:
        file_path = "".join(keys_to_typing(keys))
        path = Path(file_path)
        return file_path if path.is_file() else None
