#!/usr/bin/env python3

"""Download flags of countries (with error handling).

ThreadPool version

Sample run::

    $ python3 flags2_threadpool.py -s ERROR -e
    ERROR site: http://localhost:8003/flags
    Searching for 676 flags: from AA to ZZ
    30 concurrent connections will be used.
    --------------------
    150 flags downloaded.
    361 not found.
    165 errors.
    Elapsed time: 7.46s

"""

# tag::FLAGS2_THREADPOOL[]
from collections import Counter
from concurrent.futures import ThreadPoolExecutor, as_completed

import httpx
import tqdm  # type: ignore

from flags2_common import main, DownloadStatus
from flags2_sequential import download_one  # <1>

DEFAULT_CONCUR_REQ = 30  # <2>
MAX_CONCUR_REQ = 1000  # <3>


def download_many(cc_list: list[str],
                  base_url: str,
                  verbose: bool,
                  concur_req: int) -> Counter[DownloadStatus]:
    counter: Counter[DownloadStatus] = Counter()
    with ThreadPoolExecutor(max_workers=concur_req) as executor:  # <4>
        to_do_map = {}  # <5>
        for cc in sorted(cc_list):  # <6>
            future = executor.submit(download_one, cc,
                                     base_url, verbose)  # <7>
            to_do_map[future] = cc  # <8>
        done_iter = as_completed(to_do_map)  # <9>
        if not verbose:
            done_iter = tqdm.tqdm(done_iter, total=len(cc_list))  # <10>
        for future in done_iter:  # <11>
            try:
                status = future.result()  # <12>
            except httpx.HTTPStatusError as exc:  # <13>
                error_msg = ('HTTP error {resp.status_code}' +
                             ' - {resp.reason_phrase}')
                error_msg = error_msg.format(resp=exc.response)
            except httpx.RequestError as exc:
                error_msg = f'{exc} {type(exc)}'.strip()
            except KeyboardInterrupt:
                break
            else:
                error_msg = ''

            if error_msg:
                status = DownloadStatus.ERROR
            counter[status] += 1
            if verbose and error_msg:
                cc = to_do_map[future]  # <14>
                print(f'{cc} error: {error_msg}')

    return counter


if __name__ == '__main__':
    main(download_many, DEFAULT_CONCUR_REQ, MAX_CONCUR_REQ)
# end::FLAGS2_THREADPOOL[]
