import libtorrent as lt
import time
import sys
import bencode
import hashlib
import base64
import random
import urllib

#################################################################################
##                                                                              #
## This script can download torrents from magnet urls and .torrent files        #
## It requires two folders to be created beforehand: dwn_folder & trr_folder    #
## Torrent files should be placed inside the trr_folder.                        #
## To run you just need to pipe the torrent file name (path not required) or    #
##     the magnetic link to this script. E.g.:                                  #
##                                                                              #
##    $ cat list.txt                                                            #
##        magnet:?xt=urn:btih:LEDGO2NZVVBNULSQQYI4GPL4ISALHBL3&dn=ubuntu-17.04\ #
##            -desktop-amd64.iso&tr=http%3A%2F%2Ftorrent.ubuntu.com%3A6969%2Fa\ #
##            nounce&xl=1609039872                                              #
##        ubuntu-17.04-desktop-amd64.iso.torrent                                #
##    $ cat list.txt | xargs -I{} -n 1 -P 4 bash -c "echo '{}' | python t.py"   #
##                                                                              #
##    Note that both magnet url and the torrent file name on the list.txt file. #
##    Using xargs -P allows performing the downloads in parallel.               #
##                                                                              #
##    You might require to pip install bencode and libtorrent.                  #
##                                                                              #
#################################################################################

#CHANGE THESE##########
dwn_folder = '/tmp/'
trr_folder = 'torrents/'
#######################

link = sys.stdin.readline()
ran = random.randint(1, 999999)

print('Reading line: %s' % (link))

if ".torrent" in link:
    link = link.rstrip()
    torrent = open(trr_folder + link, 'r').read()
    metadata = bencode.bdecode(torrent)
    hashcontents = bencode.bencode(metadata['info'])
    digest = hashlib.sha1(hashcontents).digest()
    b32hash = base64.b32encode(digest)
    print('Hash: %s' % (b32hash))
    params = {'dn': metadata['info']['name'], 'tr': metadata['announce'], 'xl': metadata['info']['length']}
    print params
    paramstr = urllib.urlencode(params)
    link = 'magnet:?xt=urn:btih:%s&%s' % (b32hash, paramstr)
    print('Magnetic URL: %s' % (link))

ses = lt.session()
ses.listen_on(6881, 6891)
params = {
            'save_path': dwn_folder,
                'storage_mode': lt.storage_mode_t(2),
                    'paused': False,
                        'auto_managed': True,
                            'duplicate_is_error': True}
print link
handle = lt.add_magnet_uri(ses, link, params)
ses.start_dht()

print 'downloading metadata...'
while (not handle.has_metadata()):
        time.sleep(1)
        print 'got metadata, starting torrent download...'
        while (handle.status().state != lt.torrent_status.seeding):
                s = handle.status()
                state_str = ['queued', 'checking', 'downloading metadata','downloading', 'finished', 'seeding', 'allocating']
                print('[%d] %.2f%% complete (down: %.2f kb/s up: %.2f kB/s peers: %d) %s %.3f' % (ran, s.progress * 100, s.download_rate / 1000, s.upload_rate / 1000, s.num_peers, state_str[s.state], s.total_download/1000000))
                time.sleep(5)