import asyncio
import base64
from typing import List, Tuple, Optional

import aiohttp


async def fetch_image(url: Optional[str]) -> str:
    if not url:
        return ""

    async with aiohttp.ClientSession() as session:
        async with session.get(url) as response:
            if response.status == 200:
                image_data = await response.read()
                return base64.b64encode(image_data).decode("utf-8")
            else:
                return ""


async def fetch_images(urls: List[Optional[str]]) -> Tuple[str]:
    tasks = [fetch_image(url) for url in urls]
    return await asyncio.gather(*tasks)