functions.py

from PIL import Image
import os
from io import BytesIO
import base64
import uuid


def resize_to_fit(image, max_size):
    """
    Resize an image to fit within max_size (width, height) while preserving aspect ratio.
    Returns a new image with transparent background and the resized image centered.
    """
    image.thumbnail(max_size, Image.LANCZOS)  # Resize while keeping aspect ratio
    new_image = Image.new("RGB", max_size, (255, 255, 255))  # white background
    paste_position = (
        (max_size[0] - image.width) // 2,
        (max_size[1] - image.height) // 2,
    )
    new_image.paste(image, paste_position)
    return new_image


async def combine_images_side_by_side(image1: bytes, image2: bytes) -> str:
    """
    Takes two images, scales them to 1280x1280, combines them side by side,
    saves to tmp storage, and returns the base64 encoded image string.
    
    Args:
        image1: First image as bytes
        image2: Second image as bytes
        
    Returns:
        Base64 encoded string of the combined image
    """
    print("combine images side by side")
    # Create temp directory if it doesn't exist
    os.makedirs('tmp', exist_ok=True)
    
    # Open images from bytes
    img1 = Image.open(BytesIO(image1))
    img2 = Image.open(BytesIO(image2))
    
    # Scale both images to 1280x1280
    img1 = resize_to_fit(img1, (1280, 1280))
    img2 = resize_to_fit(img2, (1280, 1280))
    
    # Create new image with combined width (2560) and height (1280)
    combined = Image.new('RGB', (2560, 1280))
    
    # Paste images side by side
    combined.paste(img1, (0, 0))
    combined.paste(img2, (1280, 0))
    
    # Generate unique filename
    filename = f"tmp/combined_{uuid.uuid4()}.png"
    print("filename: " + filename)
    # Save image
    combined.save(filename)
    
    # Convert to base64
    with open(filename, "rb") as image_file:
        encoded_string = base64.b64encode(image_file.read()).decode('utf-8')
    
    # Clean up
    #os.remove(filename)
    print("combined images side by side")
    return encoded_string

# Example usage:
# with open('image1.jpg', 'rb') as f1, open('image2.jpg', 'rb') as f2:
#     combined_image = combine_images_side_by_side(f1.read(), f2.read())