import os
from pathlib import Path


class Config:

    def __init__(self) -> None:

        self.host = os.getenv('HOST') or '0.0.0.0'
        self.port = int(os.getenv('PORT') or 4009)

        # This directory will be searched for <site>.txt (e.g. yandex.txt)
        # Cookies are in Netscape CSV format, see yt-dlp docs
        self.cookies_dir = Path(os.getenv('COOKIES_DIR') or 'cookies')

        self.tmpl = os.path.join(
            # 1. `artists.0` instead of `artist`, because the latter can contain "feat. ..."
            # 2. as for %(field)S, see https://git.dc09.ru/DarkCat09/musicdlp/issues/3#issuecomment-210
            os.getenv('ALBUM_PATH_TMPL') or 'music/%(artists.0)S/%(album)S',
            os.getenv('TRACK_FILE_TMPL') or '%(track)S.%(ext)s',
        )

        # `or None` -- defaults to None also if PROXY is an empty string
        self.proxy = os.getenv('PROXY') or None

        self.save_lyrics = _parse_bool(os.getenv('SAVE_LYRICS'), True)
        self.save_cover = _parse_bool(os.getenv('SAVE_COVER'), True)


_config: Config | None = None


def get() -> Config:
    global _config
    if _config is None:
        _config = Config()
    return _config


def _parse_bool(val: str | None, default: bool) -> bool:
    if val is None:
        return default
    if val in {'false', 'off', 'no', '0'}:
        return False
    return bool(val)