from io import BytesIO
from typing import Tuple, Optional
from PIL import Image
import logging

logger = logging.getLogger(__name__)

def create_thumbnail(image_data: bytes, size: Tuple[int, int] = (800, 800)) -> Optional[bytes]:
    """
    Creates a thumbnail from image bytes.
    Returns the thumbnail as bytes (JPEG format) or None if failed.
    """
    try:
        with Image.open(BytesIO(image_data)) as img:
            # Convert to RGB if necessary (e.g. for RGBA/P images saving as JPEG)
            if img.mode in ('RGBA', 'P'):
                img = img.convert('RGB')
            
            img.thumbnail(size)
            
            thumb_io = BytesIO()
            img.save(thumb_io, format='JPEG', quality=85)
            thumb_io.seek(0)
            return thumb_io.read()
    except Exception as e:
        logger.error(f"Failed to create thumbnail: {e}")
        return None