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.tasks import subscribe, unsubscribe
  12 from mygpo.subscriptions import get_subscription_history, subscription_diff
  13 from mygpo.api.basic_auth import require_valid_user, check_username
  14
  15 import logging
  16
  17 logger = logging.getLogger(__name__)
  18
  19
  20 class SubscriptionsAPI(APIView):
  21     """API for sending and retrieving podcast subscription updates"""
  22
  23     def get(self, request, version, username, device_uid):
  24         """Client retrieves subscription updates"""
  25         now = datetime.utcnow()
  26         user = request.user
  27         device = get_object_or_404(Client, user=user, uid=device_uid)
  28         since = self.get_since(request)
  29         add, rem, until = self.get_changes(user, device, since, now)
  30         return JsonResponse({"add": add, "remove": rem, "timestamp": until})
  31
  32     def post(self, request, version, username, device_uid):
  33         """Client sends subscription updates"""
  34         now = get_timestamp(datetime.utcnow())
  35         logger.info(
  36             "Subscription Upload @{username}/{device_uid}".format(
  37                 username=request.user.username, device_uid=device_uid
  38             )
  39         )
  40
  41         d = get_device(
  42             request.user, device_uid, request.META.get("HTTP_USER_AGENT", "")
  43         )
  44
  45         actions = self.parsed_body(request)
  46
  47         add = list(filter(None, actions.get("add", [])))
  48         rem = list(filter(None, actions.get("remove", [])))
  49         logger.info(
  50             "Subscription Upload @{username}/{device_uid}: add "
  51             "{num_add}, remove {num_remove}".format(
  52                 username=request.user.username,
  53                 device_uid=device_uid,
  54                 num_add=len(add),
  55                 num_remove=len(rem),
  56             )
  57         )
  58
  59         update_urls = self.update_subscriptions(request.user, d, add, rem)
  60
  61         return JsonResponse({"timestamp": now, "update_urls": update_urls})
  62
  63     def update_subscriptions(self, user, device, add, remove):
  64
  65         conflicts = intersect(add, remove)
  66         if conflicts:
  67             msg = "can not add and remove '{}' at the same time".format(str(conflicts))
  68             logger.warning(msg)
  69             raise RequestException(msg)
  70
  71         add_s = list(map(normalize_feed_url, add))
  72         rem_s = list(map(normalize_feed_url, remove))
  73
  74         assert len(add) == len(add_s) and len(remove) == len(rem_s)
  75
  76         pairs = zip(add + remove, add_s + rem_s)
  77         updated_urls = list(filter(lambda pair: pair[0] != pair[1], pairs))
  78
  79         add_s = filter(None, add_s)
  80         rem_s = filter(None, rem_s)
  81
  82         # If two different URLs (in add and remove) have
  83         # been sanitized to the same, we ignore the removal
  84         rem_s = filter(lambda x: x not in add_s, rem_s)
  85
  86         for add_url in add_s:
  87             podcast = Podcast.objects.get_or_create_for_url(add_url).object
  88             subscribe(podcast.pk, user.pk, device.uid, add_url)
  89
  90         remove_podcasts = Podcast.objects.filter(urls__url__in=rem_s)
  91         for podcast in remove_podcasts:
  92             unsubscribe(podcast.pk, user.pk, device.uid)
  93
  94         return updated_urls
  95
  96     def get_changes(self, user, device, since, until):
  97         """Returns subscription changes for the given device"""
  98         history = get_subscription_history(user, device, since, until)
  99         logger.info("Subscription History: {num}".format(num=len(history)))
 100
 101         add, rem = subscription_diff(history)
 102         logger.info(
 103             "Subscription Diff: +{num_add}/-{num_remove}".format(
 104                 num_add=len(add), num_remove=len(rem)
 105             )
 106         )
 107
 108         until_ = get_timestamp(until)
 109
 110         # TODO: we'd need to get the ref_urls here somehow
 111         add_urls = [p.url for p in add]
 112         rem_urls = [p.url for p in rem]
 113         return (add_urls, rem_urls, until_)