from functools import cache
from pathlib import Path
from typing import Any, Iterator

from yaml import Loader, load


class Content:
    def __init__(self, path: Path) -> None:
        self.__path = path

    @property
    def path(self) -> Path:
        return self.__path


class ContentDirectory(Content):
    def load(self, subpath: Path) -> Content:
        current: Content = self
        for part in subpath.parts:
            if not isinstance(current, ContentDirectory):
                raise NotADirectoryError(self.path)

            current = current.__load_children(part)

        return current

    @cache  # noqa: B019
    def __load_children(self, name: str) -> Content:
        child_path = self.path / name

        if not child_path.exists():
            raise FileNotFoundError(child_path)

        if child_path.is_dir():
            return ContentDirectory(child_path)
        if child_path.is_file() and child_path.suffix in [".yml", ".yaml", ".json"]:
            return DataFile(child_path)

        raise NotImplementedError()


class DataFile(Content):
    def __init__(self, path: Path) -> None:
        super().__init__(path)
        with path.open("r", encoding="utf-8") as data_file:
            self.__data = load(data_file, Loader)

    def __getitem__(self, key: Any) -> Any:
        return self.__data.get(key)

    def __iter__(self) -> Iterator[Any]:
        yield from self.__data