mygpo/core/slugs.py

   1 from collections import defaultdict
   2
   3 from itertools import count
   4
   5 from couchdbkit.ext.django.schema import *
   6
   7 from django.utils.text import slugify
   8
   9 from mygpo.podcasts.models import Slug, Episode
  10 from mygpo.decorators import repeat_on_conflict
  11 from mygpo.utils import partition
  12
  13
  14 # TODO: move to feed-downloader?
  15 def assign_missing_episode_slugs(podcast):
  16     common_title = podcast.get_common_episode_title()
  17
  18     episodes = Episode.objects.filter(podcast=podcast, slugs__isnull=True)
  19
  20     for episode in episodes:
  21         slug = EpisodeSlug(episode, common_title).get_slug()
  22         if slug:
  23             episode.set_slug(slug)
  24
  25
  26 class SlugGenerator(object):
  27     """ Generates a unique slug for an object """
  28
  29
  30     def __init__(self, obj, override_existing=False):
  31         if obj.slug and not override_existing:
  32             raise ValueError('%(obj)s already has slug %(slug)s' % \
  33                 dict(obj=obj, slug=obj.slug))
  34
  35         self.base_slug = self._get_base_slug(obj)
  36
  37
  38     @staticmethod
  39     def _get_base_slug(obj):
  40         if not obj.title:
  41             return None
  42         base_slug = slugify(obj.title)
  43         return base_slug
  44
  45
  46     @staticmethod
  47     def _get_existing_slugs():
  48         return []
  49
  50
  51     def get_slug(self):
  52         """ Gets existing slugs and appends numbers until slug is unique """
  53         if not self.base_slug:
  54             return None
  55
  56         existing_slugs = self._get_existing_slugs()
  57
  58         if not self.base_slug in existing_slugs:
  59             return str(self.base_slug)
  60
  61         for n in count(1):
  62             tmp_slug = '%s-%d' % (self.base_slug, n)
  63             if not tmp_slug in existing_slugs:
  64                 # slugify returns SafeUnicode, we need a plain string
  65                 return str(tmp_slug)
  66
  67
  68
  69 class PodcastGroupSlug(SlugGenerator):
  70     """ Generates slugs for Podcast Groups """
  71
  72     def _get_existing_slugs(self):
  73         query = Slug.objects.filter(scope__isnull=True,
  74                                     slug__startswith=self.base_slug)
  75         return [s['slug'] for s in query]
  76
  77
  78
  79 class PodcastSlug(PodcastGroupSlug):
  80     """ Generates slugs for Podcasts """
  81
  82     @staticmethod
  83     def _get_base_slug(podcast):
  84         base_slug = SlugGenerator._get_base_slug(podcast)
  85
  86         if not base_slug:
  87             return None
  88
  89         # append group_member_name to slug
  90         if podcast.group_member_name:
  91             member_slug = slugify(podcast.group_member_name)
  92             if member_slug and not member_slug in base_slug:
  93                 base_slug = '%s-%s' % (base_slug, member_slug)
  94
  95         return base_slug
  96
  97
  98
  99 class EpisodeSlug(SlugGenerator):
 100     """ Generates slugs for Episodes """
 101
 102     def __init__(self, episode, common_title, override_existing=False):
 103         self.common_title = common_title
 104         super(EpisodeSlug, self).__init__(episode, override_existing)
 105         self.podcast_id = episode.podcast
 106
 107
 108     def _get_base_slug(self, obj):
 109
 110         number = obj.get_episode_number(self.common_title)
 111         if number:
 112             return str(number)
 113
 114         short_title = obj.get_short_title(self.common_title)
 115         if short_title:
 116             return slugify(short_title)
 117
 118         if obj.title:
 119             return slugify(obj.title)
 120
 121         return None
 122
 123
 124     def _get_existing_slugs(self):
 125         """ Episode slugs have to be unique within the Podcast """
 126         query = Slug.objects.filter(scope=self.podcast_id,
 127                                     slug__startswith=self.base_slug)
 128         return [s['slug'] for s in query]
 129
 130
 131 class SlugMixin(DocumentSchema):
 132     slug         = StringProperty()
 133     merged_slugs = StringListProperty()
 134
 135     def set_slug(self, slug):
 136         """ Set the main slug of the object """
 137
 138         if self.slug:
 139             self.merged_slugs.append(self.slug)
 140
 141         self.merged_slugs = list(set(self.merged_slugs) - set([slug]))
 142
 143         self.slug = slug
 144
 145
 146     def remove_slug(self, slug):
 147         """ Removes the slug from the object """
 148
 149         # remove main slug
 150         if self.slug == slug:
 151             self.slug = None
 152
 153         # remove from merged slugs
 154         self.merged_slugs = list(set(self.merged_slugs) - set([slug]))