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from abc import ABCMeta
from abc import abstractmethod
from contextlib import suppress
from pathlib import Path
from typing import Optional

from appium_selenium.types import AnyKey
from appium_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))

        with suppress(OSError):
            if Path(file_path).is_file():
                return file_path
