#!/usr/bin/python
# R(ange) URL D(ownloader) see usage()
# version: see below
# author: Ludovic Bellier see http://home.zyrianes.net
# licence: GNU General Public License see http://www.gnu.org/copyleft/gpl.html

version=0.9
import getopt, sys, os, re, string

def parseRangeURL(rangeURL, dry_run):
    """
    Parse range URL, and wget urls if desired (ie: not dry_run mode)

    :Parameters:
        -`rangeURL`: url like with range indication with '[' and ']' 
        -`dry_run`: if true, just echo urls, do not download
    """
    def print_url(urls):
        if type(urls) == type([]):
            for url in urls:
                print url
        else:
            print urls

    def get_files(urls):
        str_url=''
        for url in urls:
            str_url=str_url+' %s '% url
        os.system('wget %s' % str_url)

    if dry_run:
        dl_f=print_url
    else:
        dl_f=get_files
        
    urls=[]
    match=re.match('(.*)\[(.*)-(.*)\](.*)',rangeURL)
    if not match:
        urls=[rangeURL]
    else:
        base_url,range_left,range_right,end_url=match.groups()
        # number of '0', and see zfill below (don't know how to
        # use variable notation like '%.(nb_zero)d' )
        re_nb_zero=re.match('(0*)(.*)',range_left)
        if re_nb_zero: nb_zero=len(re_nb_zero.group(1))+1
        else: nb_zero=0
        for i in range(int(range_left), int(range_right)+1):
            urls.append("%s%s%s" % (base_url, string.zfill(i, nb_zero), end_url))
    # download or print
    map(dl_f,(urls,))

def usage():
    sys.stderr.write("""Range URL Downloader, version %s, gpl
Usage: rurld [-n] [-h] <URL with range>
 -n dry_run mode, just show urls
 -h this help

for example: rurld http://foo.com/pic[01-11].jpg downloads files
from http://foo.com/pic01.jpg to http://foo.com/pic11.jpg

note that [01-11] produces 01->11 and [1-11] 1->11

required: wget ( http://www.gnu.org/software/wget/wget.html )
""" % version )
    sys.exit(1)

def main(args):
    dry_run=0
    try: options, args = getopt.getopt(args[1:], 'hn')
    except:
        usage()
    for k, v in options:
        if k=='-h': usage()
        if k=='-n': dry_run=1
    if len(args)!=1: usage()
    parseRangeURL(args[0], dry_run)

if __name__=='__main__':
    main(sys.argv)