mygpo/web/utils.py

   1 from mygpo.api.models import Podcast, EpisodeAction
   2 from mygpo.web.models import Advertisement
   3 from babel import Locale, UnknownLocaleError
   4 from datetime import datetime
   5 import re
   6
   7 def get_accepted_lang(request):
   8     return list(set([s[:2] for s in request.META.get('HTTP_ACCEPT_LANGUAGE', '').split(',')]))
   9
  10 def get_podcast_languages():
  11     """
  12     Returns all 2-letter language codes that are used by podcasts.
  13
  14     It filters obviously invalid strings, but does not check if any
  15     of these codes is contained in ISO 639.
  16     """
  17
  18     langs = [x['language'] for x in Podcast.objects.values('language').distinct()]
  19     sane_lang = sanitize_language_codes(langs)
  20
  21     sane_lang.sort()
  22
  23     return sane_lang
  24
  25
  26 def sanitize_language_codes(langs):
  27     """
  28     expects a list of language codes and returns a unique lost of the first
  29     part of all items. obviously invalid entries are skipped
  30
  31     >>> sanitize_language_codes(['de-at', 'de-ch'])
  32     ['de']
  33
  34     >>> sanitize_language_codes(['de-at', 'en', 'en-gb', '(asdf', 'Deutsch'])
  35     ['de', 'en]
  36     """
  37
  38     r = '^[a-zA-Z]{2}[-_]?.*$'
  39     return list(set([l[:2] for l in langs if l and re.match(r, l)]))
  40
  41
  42 def get_language_names(lang):
  43     """
  44     Takes a list of language codes and returns a list of tuples
  45     with (code, name)
  46     """
  47     res = {}
  48     for l in lang:
  49         try:
  50             locale = Locale(l)
  51         except UnknownLocaleError:
  52             continue
  53
  54         if locale.display_name:
  55             res[l] = locale.display_name
  56
  57     return res
  58
  59
  60 class UpdatedException(Exception):
  61     """Base exception with additional payload"""
  62     def __init__(self, data):
  63         Exception.__init__(self)
  64         self.data = data
  65
  66
  67 def get_played_parts(user, episode):
  68     """
  69     return a list of length of alternating unplayed, played parts of the given
  70     episode for the given user and the resulting duration of the episode
  71
  72     If no information is available, None and the stored duration of the episode
  73     are returned
  74     """
  75     actions = EpisodeAction.objects.filter(episode=episode, user=user, action='play', playmark__isnull=False, started__isnull=False)
  76
  77     if actions.count() == 0:
  78         return None, episode.duration
  79
  80     lengths = [x.total for x in actions]
  81     median_length = lengths[len(lengths)/2]
  82
  83     # flatten (merge) all play-parts
  84     played_parts = flatten_intervals(actions)
  85
  86     # if end of last played part exceeds median length, extend episode
  87     if played_parts:
  88         length = max(median_length, played_parts[len(played_parts)-1]['end'])
  89     else:
  90         return None, episode.duration
  91
  92     #split up the played parts in alternating 'unplayed' and 'played'
  93     #sections, starting with an unplayed
  94     sections = []
  95
  96     lastpos = 0
  97     for played_part in played_parts:
  98         sections.append(played_part['start'] - lastpos)
  99         sections.append(played_part['end'] - played_part['start'])
 100         lastpos = played_part['end']
 101
 102     intsections = [int(s) for s in sections]
 103
 104     return intsections, length
 105
 106
 107 def flatten_intervals(actions):
 108     """
 109     takes a list of EpisodeActions and returns a sorted
 110     list of hashtables with start end elements of the flattened
 111     play intervals.
 112     """
 113     actions = filter(lambda x: x.started != None and x.playmark != None, actions)
 114     actions.sort(key=lambda x: x.started)
 115     played_parts = []
 116     if len(actions) == 0:
 117         return []
 118
 119     first = actions[0]
 120     flat_date = {'start': first.started, 'end': first.playmark}
 121     for action in actions:
 122         if action.started <= flat_date['end'] and action.playmark >= flat_date['end']:
 123             flat_date['end'] = action.playmark
 124         elif action.started >= flat_date['start'] and action.playmark <= flat_date['end']:
 125             # part already contained
 126             continue
 127         else:
 128             played_parts.append(flat_date)
 129             flat_date = {'start': action.started, 'end': action.playmark}
 130     played_parts.append(flat_date)
 131     return played_parts
 132
 133
 134 def get_sponsored_podcast(when=datetime.now):
 135     adv = Advertisement.objects.filter(start__lte=when, end__gte=when)
 136
 137     if not adv.exists():
 138         return None
 139     else:
 140         return adv[0]
 141
 142
 143 def get_page_list(start, total, cur, show_max):
 144     """
 145     returns a list of pages to be linked for navigation in a paginated view
 146     """
 147
 148     if show_max >= (total - start):
 149         return range(start, total+1)
 150
 151     ps = []
 152     if (cur - start) > show_max / 2:
 153         ps.extend(range(start, show_max / 4))
 154         ps.append('...')
 155         ps.extend(range(cur - show_max / 4, cur))
 156
 157     else:
 158         ps.extend(range(start, cur))
 159
 160     ps.append(cur)
 161
 162     if (total - cur) > show_max / 2:
 163         add = show_max / 2 - len(ps) # for the first pages, show more pages at the beginning
 164         ps.extend(range(cur + 1, cur + show_max / 4 + add))
 165         ps.append('...')
 166         ps.extend(range(total - show_max / 4, total + 1))
 167
 168     else:
 169         ps.extend(range(cur + 1, total + 1))
 170
 171     return ps
 172
 173
 174 def process_lang_params(request, url):
 175     if 'lang' in request.GET:
 176         lang = list(set([x for x in request.GET.get('lang').split(',') if x]))
 177
 178     if request.method == 'POST':
 179         if request.POST.get('lang'):
 180             lang = list(set(lang + [request.POST.get('lang')]))
 181         raise UpdatedException(lang)
 182
 183     if not 'lang' in request.GET:
 184         lang = get_accepted_lang(request)
 185
 186     return sanitize_language_codes(lang)
 187
 188