import os
import requests
from time import time as timer
from typing import List, Tuple
from multiprocessing.pool import ThreadPool
import shutil


def download_file(entry: Tuple[str, str]):
    path, uri = entry

    dirname = os.path.dirname(path)

    if not os.path.exists(dirname):
        try:
            os.makedirs(dirname)
        except FileExistsError:
            pass

    if not os.path.exists(path):
        r = requests.get(uri, stream=True)
        if r.status_code == 200:
            with open(path + '.crdownload', 'wb') as f:
                for chunk in r:
                    f.write(chunk)
            shutil.move(path + '.crdownload', path)
    return path


def bulk_download(path_url_list: List[Tuple[str, str]]):

    start = timer()

    print(f"Downloading {len(path_url_list)} files...")

    results = ThreadPool(8).imap_unordered(download_file, path_url_list)

    for res in results:
        print(res)

    print(f"Elapsed Time: {timer() - start}")