import asyncio
import logging
import shutil
import tempfile
import sys
from dataclasses import dataclass
from urllib.parse import urlparse
from pathlib import Path

import aiohttp

log = logging.getLogger(__name__)


@dataclass
class Context:
    session: aiohttp.ClientSession


async def main():
    wanted_date = sys.argv[1]
    urls = (
        f"https://e621.net/db_export/tags-{wanted_date}.csv.gz",
        f"https://e621.net/db_export/posts-{wanted_date}.csv.gz",
    )

    async with aiohttp.ClientSession() as session:
        ctx = Context(session)

        for url in urls:
            parsed = urlparse(url)
            parsed_path = Path(parsed.path)
            output_path = Path.cwd() / parsed_path.name
            if not output_path.exists():
                log.info("downloading %r into %s", url, output_path)
                async with ctx.session.get(url) as resp:
                    assert resp.status == 200

                    with tempfile.TemporaryFile() as temp_fd:
                        async for chunk in resp.content.iter_chunked(8192):
                            temp_fd.write(chunk)

                        # write to output
                        log.info("copying temp to output")
                        with output_path.open(mode="wb") as output_fd:
                            shutil.copyfileobj(temp_fd, output_fd)
            else:
                log.info("file %s already exists, ignoring", output_path)

        # now that everythings downloaded, compile the db


if __name__ == "__main__":
    logging.basicConfig(level=logging.INFO)
    asyncio.run(main())