#!/usr/bin/env python3
from pathlib import Path
from urllib.request import urlopen, Request
from time import sleep

def downloadurl(url):
    print("Downloading album", url)
    dpath=Path(list(filter(None, url.split('/')))[-1])
    dpath.mkdir(exist_ok=True)
    running=True
    pagenum="1"
    headers={"User-agent": 'Mozilla'}
    while running:
        sleep(0.1)
        s=urlopen(Request(url,headers=headers)).read().decode("utf-8")
        idx=s.find("<div class=\"main-image\">")
        pat="<a href="
        idx=s.find(pat,idx)+len(pat)+1
        close=s.find('"',idx)
        imgurl = s[idx:close]
        print(f"Downloading page {pagenum} from {imgurl}")
        with urlopen(Request(imgurl, headers=headers)) as r, (dpath / (pagenum+"."+imgurl.rsplit(".",1)[-1])).open('wb') as f:
            for chunk in iter(lambda: r.read(4096),b''):
                f.write(chunk)
        pat="<a class=\"on-popunder next page-numbers\" href="
        idx=s.find(pat)+len(pat)+1
        close=s.find('"',idx)
        url=s[idx:close]
        pagenum=url.split('/')[-1]
        running = s[close+1:close+6] == '>Next'
import sys
if __name__=='__main__':
    if len(sys.argv)>1:
        for url in sys.argv[1:]:
            downloadurl(url)
    else:
        url=input("Wintoddlers, please enter a url:")
        downloadurl(url)