import re

from lyra_worker.types import MBTarget

_ILLEGAL = re.compile(r'[<>:"/\\|?*\x00-\x1f]')


def safe_name(s: str) -> str:
    """A filesystem-safe path component (single segment, no separators)."""
    cleaned = _ILLEGAL.sub("_", s).strip().strip(".").strip()
    return cleaned or "Unknown"


def album_dir(dest_root: str, target: MBTarget) -> str:
    """`{dest_root}/{safe artist}/{safe album}[ (year)]`."""
    album = safe_name(target.album)
    if target.year:
        album = f"{album} ({target.year})"
    return f"{dest_root}/{safe_name(target.artist)}/{album}"