#!/usr/bin/env python3
# From https://pybay.com/site_media/slides/raymond2017-keynote/process.html
import os
import urllib.request
import urllib.error
from multiprocessing.pool import ThreadPool
from typing import List, Tuple, Union

sites: List[str] = [
#    'https://www.yahoo.com/',
#    'http://www.cnn.com',
#    'http://www.python.org',
#    'http://www.jython.org',
    'http://www.pypy.org',
    'http://www.perl.org',
#    'http://www.cisco.com',
#    'http://www.facebook.com',
#    'http://www.twitter.com',
#    'http://www.macrumors.com/',
#    'http://arstechnica.com/',
#    'http://www.reuters.com/',
#    'http://abcnews.go.com/',
#    'http://www.cnbc.com/',
]


def sitesize(url: str) -> Tuple[str, Union[int, str]]:
    ''' Determine the size of a website '''
    try:
        with urllib.request.urlopen(url) as f:
            page = f.read()
        return url, len(page)
    except urllib.error.HTTPError as e:
        return url, str(e)
    except urllib.error.URLError as e:
        return url, str(e)


def run() -> None:
    # Network bound: Use max(); CPU bound: Use min()
    pool = ThreadPool(max(len(sites), os.cpu_count()))
    for result in pool.imap_unordered(sitesize, sites):
        print(result)


if __name__ == '__main__':
    run()