mygpo/api/subscriptions.py

   1 #
   2 # This file is part of my.gpodder.org.
   3 #
   4 # my.gpodder.org is free software: you can redistribute it and/or modify it
   5 # under the terms of the GNU Affero General Public License as published by
   6 # the Free Software Foundation, either version 3 of the License, or (at your
   7 # option) any later version.
   8 #
   9 # my.gpodder.org is distributed in the hope that it will be useful, but
  10 # WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  11 # or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public
  12 # License for more details.
  13 #
  14 # You should have received a copy of the GNU Affero General Public License
  15 # along with my.gpodder.org. If not, see <http://www.gnu.org/licenses/>.
  16 #
  17
  18 from datetime import datetime
  19
  20 from django.shortcuts import get_object_or_404
  21
  22 from mygpo.podcasts.models import Podcast
  23 from mygpo.api import APIView, RequestException
  24 from mygpo.api.httpresponse import JsonResponse
  25 from mygpo.api.backend import get_device
  26 from mygpo.utils import get_timestamp, normalize_feed_url, intersect
  27 from mygpo.users.models import Client
  28 from mygpo.subscriptions import (subscribe, unsubscribe,
  29                                  get_subscription_history, subscription_diff)
  30
  31 import logging
  32 logger = logging.getLogger(__name__)
  33
  34
  35 class SubscriptionsAPI(APIView):
  36     """ API for sending and retrieving podcast subscription updates """
  37
  38     def get(self, request, version, username, device_uid):
  39         """ Client retrieves subscription updates """
  40         now = datetime.utcnow()
  41         user = request.user
  42         device = get_object_or_404(Client, user=user, uid=device_uid)
  43         since = self.get_since(request)
  44         add, rem, until = self.get_changes(user, device, since, now)
  45         return JsonResponse({
  46             'add': add,
  47             'remove': rem,
  48             'timestamp': until
  49         })
  50
  51     def post(self, request, version, username, device_uid):
  52         """ Client sends subscription updates """
  53         now = get_timestamp(datetime.utcnow())
  54         logger.info('Subscription Upload @{username}/{device_uid}'.format(
  55             username=request.user.username, device_uid=device_uid))
  56
  57         d = get_device(request.user, device_uid,
  58                        request.META.get('HTTP_USER_AGENT', ''))
  59
  60         actions = self.parsed_body(request)
  61
  62         add = list(filter(None, actions.get('add', [])))
  63         rem = list(filter(None, actions.get('remove', [])))
  64         logger.info('Subscription Upload @{username}/{device_uid}: add '
  65             '{num_add}, remove {num_remove}'.format(
  66             username=request.user.username, device_uid=device_uid,
  67             num_add=len(add), num_remove=len(rem)))
  68
  69         update_urls = self.update_subscriptions(request.user, d, add, rem)
  70
  71         return JsonResponse({
  72             'timestamp': now,
  73             'update_urls': update_urls,
  74         })
  75
  76     def update_subscriptions(self, user, device, add, remove):
  77
  78         conflicts = intersect(add, remove)
  79         if conflicts:
  80             msg = "can not add and remove '{}' at the same time".format(
  81                 str(conflicts))
  82             logger.warn(msg)
  83             raise RequestException(msg)
  84
  85         add_s = list(map(normalize_feed_url, add))
  86         rem_s = list(map(normalize_feed_url, remove))
  87
  88         assert len(add) == len(add_s) and len(remove) == len(rem_s)
  89
  90         pairs = zip(add + remove, add_s + rem_s)
  91         updated_urls = list(filter(lambda pair: pair[0] != pair[1], pairs))
  92
  93         add_s = filter(None, add_s)
  94         rem_s = filter(None, rem_s)
  95
  96         # If two different URLs (in add and remove) have
  97         # been sanitized to the same, we ignore the removal
  98         rem_s = filter(lambda x: x not in add_s, rem_s)
  99
 100         for add_url in add_s:
 101             podcast = Podcast.objects.get_or_create_for_url(add_url)
 102             subscribe(podcast, user, device, add_url)
 103
 104         remove_podcasts = Podcast.objects.filter(urls__url__in=rem_s)
 105         for podcast in remove_podcasts:
 106             unsubscribe(podcast, user, device)
 107
 108         return updated_urls
 109
 110     def get_changes(self, user, device, since, until):
 111         """ Returns subscription changes for the given device """
 112         history = get_subscription_history(user, device, since, until)
 113         logger.info('Subscription History: {num}'.format(num=len(history)))
 114
 115         add, rem = subscription_diff(history)
 116         logger.info('Subscription Diff: +{num_add}/-{num_remove}'.format(
 117             num_add=len(add), num_remove=len(rem)))
 118
 119         until_ = get_timestamp(until)
 120
 121         # TODO: we'd need to get the ref_urls here somehow
 122         add_urls = [p.url for p in add]
 123         rem_urls = [p.url for p in rem]
 124         return (add_urls, rem_urls, until_)