mygpo/users/subscriptions.py

   1 from mygpo.db.couchdb.user import get_num_listened_episodes
   2
   3
   4 class PodcastSorter(object):
   5     """ Sorts a list of podcast """
   6
   7     def __init__(self, podcasts):
   8         self.podcasts = podcasts
   9         self.sorted_podcasts = None
  10
  11
  12     def _sort(self):
  13         return self.podcasts
  14
  15
  16     def __len__(self):
  17         return len(self.podcasts)
  18
  19
  20     def __getitem__(self, val):
  21         if self.sorted_podcasts is None:
  22             self.sorted_podcasts = self._sort()
  23
  24         return self.sorted_podcasts.__getitem__(val)
  25
  26     def __iter__(self):
  27         if self.sorted_podcasts is None:
  28             self.sorted_podcasts = self._sort()
  29
  30         return iter(self.sorted_podcasts)
  31
  32
  33
  34 class PodcastPercentageListenedSorter(PodcastSorter):
  35     """ Sorts podcasts by the percentage of listened episodes
  36
  37     Adds the attributes percent_listened and episodes_listened to the podcasts
  38
  39     Cost: 1 DB query """
  40
  41     def __init__(self, podcasts, user):
  42         super(PodcastPercentageListenedSorter, self).__init__(podcasts)
  43         self.user = user
  44
  45
  46     def _sort(self):
  47
  48         SORT_KEY = lambda podcast: podcast.percent_listened
  49
  50         counts = dict(get_num_listened_episodes(self.user))
  51         for podcast in self.podcasts:
  52             c = counts.get(podcast.get_id(), 0)
  53             if podcast.episode_count:
  54                 podcast.percent_listened = c / float(podcast.episode_count)
  55                 podcast.episodes_listened = c
  56             else:
  57                 podcast.percent_listened = 0
  58                 podcast.episodes_listened = 0
  59
  60         return sorted(self.podcasts, key=SORT_KEY, reverse=True)