import argparse
import requests
import os
from lxml import html

parser = argparse.ArgumentParser()
parser.add_argument("url", type=str,
                    help="download an slideshare presentation given the url")
args = parser.parse_args()


def slideshare_down(request_url):
    page = requests.get(request_url)
    tree = html.fromstring(page.text)
    counter = 1

    all_images = tree.xpath('//img[@class="slide_image"]')
    print(("Downloading presentation images."))
    for img in all_images:
        file_url = img.get("data-full")

        input_page = "slide_%d.jpg" % counter
        os.system('curl -s "%s" -o %s' % (file_url, input_page))

        counter += 1

    print("Merging images with ImageMagick, please wait.")
    os.system('convert -density 300 *.jpg -quality 100 presentation.pdf')
    os.system('rm slide_*.jpg')
    print("Done!")

slideshare_down(args.url)