from PIL import Image
import io
import base64
import logging # Import logging

# Get a logger instance for this module
logger = logging.getLogger(__name__)

def create_thumbnail_from_bytes(image_data_bytes, size=(128, 128), output_format='JPEG'):
    """
    Creates a thumbnail from image data (bytes).
    Returns the thumbnail as bytes.
    """
    try:
        img = Image.open(io.BytesIO(image_data_bytes))
        img.thumbnail(size)

        thumbnail_buffer = io.BytesIO()
        # Ensure the output format is supported by Pillow and the original image
        if img.mode == 'RGBA' and output_format == 'JPEG':
            # Convert RGBA to RGB for JPEG output to avoid errors with alpha channel
            img = img.convert('RGB')
            logger.debug("Converted RGBA image to RGB for JPEG output.")
        img.save(thumbnail_buffer, format=output_format)
        thumbnail_buffer.seek(0)
        logger.info(f"Thumbnail created from bytes. Size: {size}, Format: {output_format}")
        return thumbnail_buffer.getvalue()
    except Exception as e:
        logger.error(f"Error creating thumbnail from bytes: {e}")
        return None

def create_thumbnail_from_base64(base64_string, size=(128, 128), output_format='JPEG'):
    """
    Decodes a base64 image string, creates a thumbnail, and returns the thumbnail as bytes.
    """
    try:
        decoded_image_data = base64.b64decode(base64_string)
        logger.debug("Base64 string decoded successfully.")
        return create_thumbnail_from_bytes(decoded_image_data, size, output_format)
    except base64.binascii.Error as e:
        logger.error(f"Invalid base64 string provided: {e}")
        return None
    except Exception as e:
        logger.error(f"Error creating thumbnail from base64 string: {e}")
        return None