mygpo/core/podcasts.py

   1 from itertools import chain, islice
   2
   3 from mygpo.core.models import Podcast, PodcastGroup
   4 from mygpo.core.proxy import proxy_object
   5 from mygpo.db.couchdb.episode import episodes_for_podcast
   6 from mygpo.utils import sorted_chain
   7
   8
   9 # the default sort order for podcasts
  10 PODCAST_SORT=lambda p: p.display_title
  11
  12
  13 class PodcastSet(set):
  14     """ Represents a set of podcasts """
  15
  16     def __init__(self, podcasts=None):
  17         self.podcasts = podcasts or []
  18
  19
  20     def get_newest_episodes(self, max_date, num_episodes, max_per_podcast=5):
  21         """ Returns the newest episodes for a set of podcasts """
  22
  23         podcast_key = lambda p: p.latest_episode_timestamp
  24
  25         podcasts = filter(lambda p: p.latest_episode_timestamp, self.podcasts)
  26         podcasts = sorted(podcasts, key=podcast_key, reverse=True)
  27
  28         # we need at most num_episodes podcasts
  29         podcasts = podcasts[:num_episodes]
  30
  31         podcast_dict = dict((p.get_id(), p) for p in podcasts)
  32
  33         links = [(p.latest_episode_timestamp, lazy_call(episodes_for_podcast,
  34                     p, since=1, until=max_date, descending=True,
  35                     limit=max_per_podcast) ) for p in podcasts]
  36
  37         episodes = sorted_chain(links, lambda e: e.released, reverse=True)
  38
  39         for episode in islice(episodes, num_episodes):
  40             p = podcast_dict.get(episode.podcast, None)
  41             yield proxy_object(episode, podcast=p)
  42
  43
  44 def lazy_call(f, *args, **kwargs):
  45     for x in f(*args, **kwargs):
  46         yield x
  47
  48
  49 def individual_podcasts(pg):
  50     """ returns individual podcasts for an iter of Podcast(Group) objects """
  51
  52     for p in pg:
  53         if isinstance(p, Podcast):
  54             yield p
  55
  56         elif isinstance(p, PodcastGroup):
  57             for x in p.podcasts:
  58                 yield x