mygpo/api/subscriptions.py

   1 from datetime import datetime
   2
   3 from django.shortcuts import get_object_or_404
   4
   5 from mygpo.podcasts.models import Podcast
   6 from mygpo.api import APIView, RequestException
   7 from mygpo.api.httpresponse import JsonResponse
   8 from mygpo.api.backend import get_device
   9 from mygpo.utils import get_timestamp, normalize_feed_url, intersect
  10 from mygpo.users.models import Client
  11 from mygpo.subscriptions import (subscribe, unsubscribe,
  12                                  get_subscription_history, subscription_diff)
  13
  14 import logging
  15 logger = logging.getLogger(__name__)
  16
  17
  18 class SubscriptionsAPI(APIView):
  19     """ API for sending and retrieving podcast subscription updates """
  20
  21     def get(self, request, version, username, device_uid):
  22         """ Client retrieves subscription updates """
  23         now = datetime.utcnow()
  24         user = request.user
  25         device = get_object_or_404(Client, user=user, uid=device_uid)
  26         since = self.get_since(request)
  27         add, rem, until = self.get_changes(user, device, since, now)
  28         return JsonResponse({
  29             'add': add,
  30             'remove': rem,
  31             'timestamp': until
  32         })
  33
  34     def post(self, request, version, username, device_uid):
  35         """ Client sends subscription updates """
  36         now = get_timestamp(datetime.utcnow())
  37         logger.info('Subscription Upload @{username}/{device_uid}'.format(
  38             username=request.user.username, device_uid=device_uid))
  39
  40         d = get_device(request.user, device_uid,
  41                        request.META.get('HTTP_USER_AGENT', ''))
  42
  43         actions = self.parsed_body(request)
  44
  45         add = list(filter(None, actions.get('add', [])))
  46         rem = list(filter(None, actions.get('remove', [])))
  47         logger.info('Subscription Upload @{username}/{device_uid}: add '
  48             '{num_add}, remove {num_remove}'.format(
  49             username=request.user.username, device_uid=device_uid,
  50             num_add=len(add), num_remove=len(rem)))
  51
  52         update_urls = self.update_subscriptions(request.user, d, add, rem)
  53
  54         return JsonResponse({
  55             'timestamp': now,
  56             'update_urls': update_urls,
  57         })
  58
  59     def update_subscriptions(self, user, device, add, remove):
  60
  61         conflicts = intersect(add, remove)
  62         if conflicts:
  63             msg = "can not add and remove '{}' at the same time".format(
  64                 str(conflicts))
  65             logger.warn(msg)
  66             raise RequestException(msg)
  67
  68         add_s = list(map(normalize_feed_url, add))
  69         rem_s = list(map(normalize_feed_url, remove))
  70
  71         assert len(add) == len(add_s) and len(remove) == len(rem_s)
  72
  73         pairs = zip(add + remove, add_s + rem_s)
  74         updated_urls = list(filter(lambda pair: pair[0] != pair[1], pairs))
  75
  76         add_s = filter(None, add_s)
  77         rem_s = filter(None, rem_s)
  78
  79         # If two different URLs (in add and remove) have
  80         # been sanitized to the same, we ignore the removal
  81         rem_s = filter(lambda x: x not in add_s, rem_s)
  82
  83         for add_url in add_s:
  84             podcast = Podcast.objects.get_or_create_for_url(add_url)
  85             subscribe(podcast, user, device, add_url)
  86
  87         remove_podcasts = Podcast.objects.filter(urls__url__in=rem_s)
  88         for podcast in remove_podcasts:
  89             unsubscribe(podcast, user, device)
  90
  91         return updated_urls
  92
  93     def get_changes(self, user, device, since, until):
  94         """ Returns subscription changes for the given device """
  95         history = get_subscription_history(user, device, since, until)
  96         logger.info('Subscription History: {num}'.format(num=len(history)))
  97
  98         add, rem = subscription_diff(history)
  99         logger.info('Subscription Diff: +{num_add}/-{num_remove}'.format(
 100             num_add=len(add), num_remove=len(rem)))
 101
 102         until_ = get_timestamp(until)
 103
 104         # TODO: we'd need to get the ref_urls here somehow
 105         add_urls = [p.url for p in add]
 106         rem_urls = [p.url for p in rem]
 107         return (add_urls, rem_urls, until_)