from __future__ import annotations

from pathlib import Path
from typing import Any

from app.config import settings


def asset_library_dir() -> Path:
    return Path(settings.upload_dir) / "asset-libraries"


def list_asset_library_blends() -> list[Path]:
    directory = asset_library_dir()
    if not directory.is_dir():
        return []

    return sorted(
        (path for path in directory.glob("*.blend") if path.is_file()),
        key=lambda path: (path.stat().st_mtime, path.name),
        reverse=True,
    )


def resolve_asset_library_blend_path(
    *,
    blend_file_path: str | None = None,
    asset_library_id: Any | None = None,
) -> str | None:
    """Resolve the best available .blend path for an asset library.

    Resolution order:
    1. explicit configured path, when it exists
    2. canonical uploads/asset-libraries/<id>.blend path
    3. newest available .blend under uploads/asset-libraries
    """
    if blend_file_path:
        configured = Path(blend_file_path)
        if configured.is_file():
            return str(configured)

    if asset_library_id:
        candidate = asset_library_dir() / f"{asset_library_id}.blend"
        if candidate.is_file():
            return str(candidate)

    available = list_asset_library_blends()
    if available:
        return str(available[0])

    return None