"""Image post-processing helpers (thumbnail generation, etc.)."""
from pathlib import Path

from PIL import Image

from app.core.config import settings


def generate_thumbnail(file_path: str, max_size: int = 400) -> str:
    full = settings.upload_path / file_path
    if not full.exists():
        return file_path

    thumb_dir = full.parent / "thumbs"
    thumb_dir.mkdir(exist_ok=True)
    thumb_path = thumb_dir / full.name

    try:
        with Image.open(full) as img:
            img.thumbnail((max_size, max_size))
            img.save(thumb_path)
        return str(thumb_path.relative_to(settings.upload_path))
    except Exception:
        return file_path