get-inputs

#!/usr/bin/env python3
import argparse
from datetime import datetime, timedelta, timezone
from pathlib import Path
import shutil
import sys
import time
from urllib.error import HTTPError
from urllib.request import urlopen, Request

tz = timezone(timedelta(hours=-5))


def main():
    terminal_output = sys.stdout if sys.stdout.isatty(
    ) else sys.stderr if sys.stderr.isatty() else None

    parser = argparse.ArgumentParser()
    group = parser.add_mutually_exclusive_group()
    group.add_argument("-n", "--dry-run", action='store_true')
    group.add_argument("-o", "--overwrite", action='store_true', dest='force')
    group = parser.add_mutually_exclusive_group()
    group.add_argument("-s", "--session")
    group.add_argument("-S",
                       "--session-file",
                       metavar='FILE',
                       type=argparse.FileType())
    parser.add_argument("-y", "--year", type=int, default=2023)
    parser.add_argument("days", metavar='DAY', type=int, nargs='*')
    args = parser.parse_args()

    dry_run, force, session = args.dry_run, args.force, args.session
    if not session:
        session_file = args.session_file
        if not session_file:
            session_file = open(Path.home() / '.aocrc')
        with session_file:
            session = session_file.read().strip()

    year, days = args.year, args.days
    base = datetime(year, 12, 1, 0, 0, 0, 0, tz)
    if days:
        days = sorted(set(days))
    else:
        days = (datetime.now(tz) - base).days + 1
        days = range(1, max(0, min(25, days)) + 1)

    for day in days:
        file = f"day{day}.txt"
        if not force and Path(file).exists():
            print(f"{file} already exists")
            continue
        if not dry_run:
            target = base + timedelta(days=day - 1)
            while True:
                now = datetime.now(tz)
                if now >= target:
                    break
                delta = target - now
                message = f"{file} available in {delta}"
                if terminal_output:
                    print(message, end='', file=terminal_output, flush=True)
                    if delta > timedelta(hours=2):
                        delta = delta % timedelta(hours=1)
                    elif delta > timedelta(minutes=2):
                        delta = delta % timedelta(minutes=1)
                    elif delta > timedelta(seconds=2):
                        delta = delta % timedelta(seconds=1)
                    elif delta > timedelta(milliseconds=20):
                        delta = delta % timedelta(milliseconds=10)
                    time.sleep(delta.total_seconds())
                    print('\033[2K\r',
                          end='',
                          file=terminal_output,
                          flush=True)
                else:
                    print(message)
                    time.sleep(delta.total_seconds())
        url = f"https://www.adventofcode.com/{year}/day/{day}/input"
        print(f"{file} = {url}")
        if dry_run:
            continue
        request = Request(
            url,
            headers={
                "User-Agent":
                "https://github.com/ephemient/aoc2023/blob/main/get-inputs",
                "Cookie": f"session={session}"
            })
        response = urlopen(request)
        if response.status != 200:
            raise HTTPError(response.url, response.code, response.msg,
                            response.headers, None)
        with response:
            with open(file, 'wb') as f:
                shutil.copyfileobj(response, f)


if __name__ == "__main__":
    main()