mygpo/core/podcasts.py

   1 from itertools import chain, islice
   2
   3 from mygpo.core.models import Podcast
   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 class PodcastSet(set):
  10     """ Represents a set of podcasts """
  11
  12     def __init__(self, podcasts=None):
  13         self.podcasts = podcasts or []
  14
  15
  16     def get_newest_episodes(self, max_date, num_episodes, max_per_podcast=5):
  17         """ Returns the newest episodes for a set of podcasts """
  18
  19         podcast_key = lambda p: p.latest_episode_timestamp
  20
  21         podcasts = filter(lambda p: p.latest_episode_timestamp, self.podcasts)
  22         podcasts = sorted(podcasts, key=podcast_key, reverse=True)
  23
  24         # we need at most num_episodes podcasts
  25         podcasts = podcasts[:num_episodes]
  26
  27         podcast_dict = dict((p.get_id(), p) for p in podcasts)
  28
  29         links = [(p.latest_episode_timestamp, lazy_call(episodes_for_podcast,
  30                     p, since=1, until=max_date, descending=True,
  31                     limit=max_per_podcast) ) for p in podcasts]
  32
  33         episodes = sorted_chain(links, lambda e: e.released, reverse=True)
  34
  35         for episode in islice(episodes, num_episodes):
  36             p = podcast_dict.get(episode.podcast, None)
  37             yield proxy_object(episode, podcast=p)
  38
  39
  40 def lazy_call(f, *args, **kwargs):
  41     for x in f(*args, **kwargs):
  42         yield x