# Adapted from djpubsubhubbub. See License: http://git.participatoryculture.org/djpubsubhubbub/tree/LICENSE

from vendor import feedparser
import random
import datetime

from django.http import HttpResponse, Http404
from django.shortcuts import get_object_or_404

from apps.push.models import PushSubscription
from apps.push.signals import verified
from apps.rss_feeds.models import MFetchHistory
from utils import log as logging

def push_callback(request, push_id):
    if request.method == 'GET':
        mode = request.GET['hub.mode']
        topic = request.GET['hub.topic']
        challenge = request.GET['hub.challenge']
        lease_seconds = request.GET.get('hub.lease_seconds')
        verify_token = request.GET.get('hub.verify_token', '')

        if mode == 'subscribe':
            if not verify_token.startswith('subscribe'):
                raise Http404
            subscription = get_object_or_404(PushSubscription,
                                             pk=push_id,
                                             topic=topic,
                                             verify_token=verify_token)
            subscription.verified = True
            subscription.set_expiration(int(lease_seconds))
            subscription.save()
            subscription.feed.setup_push()

            logging.debug('   ---> [%-30s] [%s] ~BBVerified PuSH' % (unicode(subscription.feed)[:30], subscription.feed_id))

            verified.send(sender=subscription)

        return HttpResponse(challenge, content_type='text/plain')
    elif request.method == 'POST':
        subscription = get_object_or_404(PushSubscription, pk=push_id)
        fetch_history = MFetchHistory.feed(subscription.feed_id)
        latest_push_date_delta = None
        if fetch_history and fetch_history.get('push_history'):
            latest_push = fetch_history['push_history'][0]['push_date']
            latest_push_date = datetime.datetime.strptime(latest_push, '%Y-%m-%d %H:%M:%S')
            latest_push_date_delta = datetime.datetime.now() - latest_push_date
            if latest_push_date > datetime.datetime.now() - datetime.timedelta(minutes=1):
                logging.debug('   ---> [%-30s] ~SN~FBSkipping feed fetch, pushed %s seconds ago' % (unicode(subscription.feed)[:30], latest_push_date_delta.seconds))
                return HttpResponse('Slow down, you just pushed %s seconds ago...' % latest_push_date_delta.seconds, status=429)
                
        # XXX TODO: Optimize this by removing feedparser. It just needs to find out
        # the hub_url or topic has changed. ElementTree could do it.
        if random.random() < 0.1:
            parsed = feedparser.parse(request.raw_post_data)
            subscription.check_urls_against_pushed_data(parsed)

        # Don't give fat ping, just fetch.
        # subscription.feed.queue_pushed_feed_xml(request.raw_post_data)
        if subscription.feed.active_premium_subscribers >= 1:
            subscription.feed.queue_pushed_feed_xml("Fetch me", latest_push_date_delta=latest_push_date_delta)
            MFetchHistory.add(feed_id=subscription.feed_id, 
                              fetch_type='push')
        else:
            logging.debug('   ---> [%-30s] ~FBSkipping feed fetch, no actives: %s' % (unicode(subscription.feed)[:30], subscription.feed))
        
        return HttpResponse('OK')
    return Http404