#coding: utf8
import threading
import traceback
import random
import time
import os
import socket

import libtorrent as lt

threading.stack_size(200*1024)
socket.setdefaulttimeout(30)

def fetch_torrent(session, ih, timeout):
    name = ih.upper()
    url = 'magnet:?xt=urn:btih:%s' % (name,)
    data = ''
    params = {
        'save_path': '/tmp/downloads/',
        'storage_mode': lt.storage_mode_t(2),
        'paused': False,
        'auto_managed': False,
        'duplicate_is_error': True}
    try:
        handle = lt.add_magnet_uri(session, url, params)
    except:
        return None
    status = session.status()
    #print 'downloading metadata:', url
    handle.set_sequential_download(1)
    meta = None
    down_time = time.time()
    down_path = None
    for i in xrange(0, timeout):
        if handle.has_metadata():
            info = handle.get_torrent_info()
            down_path = '/tmp/downloads/%s' % info.name()
            #print 'status', 'p', status.num_peers, 'g', status.dht_global_nodes, 'ts', status.dht_torrents, 'u', status.total_upload, 'd', status.total_download
            meta = info.metadata()
            break
        time.sleep(1)
    if down_path and os.path.exists(down_path):
        os.system('rm -rf "%s"' % down_path)
    session.remove_torrent(handle)
    return meta


def download_metadata(address, binhash, metadata_queue, timeout=40):
    metadata = None
    start_time = time.time()
    try:
        session = lt.session()
        r = random.randrange(10000, 50000)
        session.listen_on(r, r+10)
        session.add_dht_router('router.bittorrent.com',6881)
        session.add_dht_router('router.utorrent.com',6881)
        session.add_dht_router('dht.transmission.com',6881)
        session.add_dht_router('127.0.0.1',6881)
        session.start_dht()
        metadata = fetch_torrent(session, binhash.encode('hex'), timeout)
        session = None
    except:
        traceback.print_exc()
    finally:
        metadata_queue.put((binhash, address, metadata, 'lt', start_time))