import aiohttp
import asyncio
import signal
from asyncio import Event

USER_AGENT = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.135 Safari/537.36 Edge/12.246"
HEADERS = {'User-Agent': USER_AGENT}

def warmup():
    # тут рутина, что добывает список с URL
    return []

def cooldown(pending_urls):
    # тут рутина, чтоб схоронить необработанные URL после получения SIGINT
    pass

# спиздил из https://medium.com/@rob.blackbourn/a-python-asyncio-cancellation-pattern-a808db861b84
def make_cancellation_event(loop = None):
    # Create an event that gets set when the program is interrupted.
    cancellation_event = Event()
    if loop is None:
        loop = asyncio.get_event_loop()
    def cancel(name, num):
        msg = f'Received signal {name}'
        if num == signal.SIGINT:
            print(msg)
        else:
            print(msg)
        cancellation_event.set()
    for signame in ['SIGINT', 'SIGTERM']:
        signum = getattr(signal, signame)
        loop.add_signal_handler(signum, cancel, signame, signum)
    return cancellation_event

async def get_file(session, url):
    async with session.get(url, headers=HEADERS) as resp:
        if resp.status == 200:
            content = await resp.read()
            with open(url[-7:]) as af:
                await af.write(content)
    return url

async def main():
    untouched = warmup()
    cancellation_event = make_cancellation_event()
    cancellation_task = asyncio.create_task(cancellation_event.wait())
    async with aiohttp.ClientSession() as session:
        done, pending = await asyncio.wait(
                [cancellation_task] + [get_file(session, some) for some in untouched])

        # хуй понять, как тут дальше и когда вызвать cooldown(pending_urls)


if __name__ == '__main__':
    asyncio.run(main())