from pathlib import Path

from app.settings import settings

# Instance state, not baked into the image -- seeded from
# pipeline/configs/artist-canonical.list.example on first boot (see
# entrypoint.sh) and edited from here after that. Read directly by
# normalize-artist-casing.py at run time, same file, no caching.


def _path() -> Path:
    return settings.pipeline_config_dir / "artist-canonical.list"


def _is_entry_line(line: str) -> bool:
    stripped = line.strip()
    return bool(stripped) and not stripped.startswith("#")


def list_entries() -> list[str]:
    path = _path()
    if not path.exists():
        return []
    return [line.strip() for line in path.read_text(encoding="utf-8").splitlines() if _is_entry_line(line)]


def add_entry(name: str) -> None:
    """Append a canonical name, or if one already matches case-insensitively
    (the whole point of this list is one canonical casing per artist),
    replace that line's casing instead of adding a duplicate."""
    name = name.strip()
    if not name:
        raise ValueError("artist name cannot be empty")

    path = _path()
    path.parent.mkdir(parents=True, exist_ok=True)
    lines = path.read_text(encoding="utf-8").splitlines() if path.exists() else []

    for i, line in enumerate(lines):
        if _is_entry_line(line) and line.strip().lower() == name.lower():
            lines[i] = name
            path.write_text("\n".join(lines) + "\n", encoding="utf-8")
            return

    lines.append(name)
    path.write_text("\n".join(lines) + "\n", encoding="utf-8")


def remove_entry(name: str) -> None:
    path = _path()
    if not path.exists():
        return
    lines = path.read_text(encoding="utf-8").splitlines()
    lines = [line for line in lines if not (_is_entry_line(line) and line.strip() == name)]
    path.write_text("\n".join(lines) + "\n", encoding="utf-8")