ostr

import argparse
from datetime import date
from calendar import month_name
from threading import Thread
from queue import Queue

from lxml import html
import requests


# test
s800x600 = u'800\xd7600'

MAIN_URL = 'https://www.smashingmagazine.com/'
#ADD_URL = f'{year}/{month}/desktop-wallpaper-calendars-{Month}-{year_calc}/'
ADD_URL = '{year}/{month}/desktop-wallpaper-calendars-{Month}-{year_calc}/'
WITH_CALENDAR = 2
WITHOUT_CALENDAR = 3

ACTUAL = WITH_CALENDAR


def is_year_valid(year):
    """ validate year

    :type year: int
    :rtype:  int
    """
    year = int(year)
    today_year = date.today().year
    if 2000 <= year <= today_year:
        return year
    raise argparse.ArgumentTypeError("%s is not between 2000 and %s" % (year, today_year))


def is_month_valid(month):
    """ validate month

    :type month: int
    :rtype: int
    """
    month = int(month)
    if 1 <= month <= 12:
        return month
    raise argparse.ArgumentTypeError("%s is not between 1 and 12" % month)


def get_wallps_urls(month, year):
    """ get all possible wallp urls by resolution

    :type month: int
    :type year: int
    :return: list(str)
    """
    urls = []

    month_calc = month_name[month % 12 + 1].lower()
    # if it is a december (12) => calculated year must be incremented
    year_calc = year + 1 if month == 12 else year
    # number month should be like '04'
    month = str(month).zfill(2)

    r = requests.get(MAIN_URL+ADD_URL.format(
        month=month, year=year, Month=month_calc, year_calc=year_calc
    ))

    if r.status_code == 200:
        tree = html.fromstring(r.content)
        urls.extend(tree.xpath(u"//html/body/main//div[contains(@class, 'col')\
                                                and contains(@class, 'main')]\
                            /article[contains(@class, 'tag-wallpapers')]\
                            /ul[position() > 3]\
                            /li[position()={calendar}]\
                            /a[text()='{size}']/@href".format(calendar=ACTUAL, size=s800x600)))
    """
    tree.xpath("//html/body/main//div[@id='content']")
    """
    return urls


def fetch_by_urls(urls):
    """ download images given urls
    and save in file

    :type urls: list(str)
    :return: None
    """
    print('start fetching %s images' % len(urls))
    for url in urls:
        r = requests.get(url, stream=True)
        if r.status_code == 200:
            with open(url.split('/')[-1], 'wb') as f:
                for chunk in r:
                    f.write(chunk)


if __name__ == '__main__':

    parser = argparse.ArgumentParser(description='wallpapers downloader')
    parser.add_argument('--month', metavar='4', type=is_month_valid,
                        help='choose a month number', required=True,)
    parser.add_argument('--year', metavar='2017', type=is_year_valid,
                        help='choose a year number', required=True)
    # parser.add_argument('--resolution', metavar='800x600', type=str,
    #                     help='choose a resolution', required=True)
    # parser.add_argument('--resolution', metavar='800x600', type=str,
    #                     help='choose a resolution', required=True)

    args = parser.parse_args()

    urls = get_wallps_urls(month=args.month, year=args.year)
    if urls:
        queue = Queue()
        t1 = Thread(target=fetch_by_urls, args=(urls[:len(urls)/2],))
        t2 = Thread(target=fetch_by_urls, args=(urls[len(urls)/2:],))
        queue.put(t1)
        t1.start()
        queue.put(t2)
        t2.start()

        queue.join()

        print('done')
    else:
        print('something wrong')
        exit(1)