def _decorator(request, podcast_id, *args, **kwargs):

        try:
            podcast = Podcast.objects.filter(id=podcast_id)
            podcast = podcast.prefetch_related('slugs', 'urls').get()

            # if the podcast has a slug, redirect to its canonical URL
            if podcast.slug:
                return HttpResponseRedirect(get_podcast_link_target(podcast))

            return f(request, podcast, *args, **kwargs)

        except Podcast.DoesNotExist:
            podcast = get_object_or_404(Podcast, merged_uuids__uuid=podcast_id)
            return HttpResponseRedirect(get_podcast_link_target(podcast))

def podcast_data(obj, domain, scaled_logo_size=64):
    if obj is None:
        raise ValueError('podcast should not be None')

    if isinstance(obj, SubscribedPodcast):
        url = obj.ref_url
        podcast = obj.podcast
    else:
        podcast = obj
        url = podcast.url

    subscribers = podcast.subscribers
    last_subscribers = podcast.subscribers

    scaled_logo_url = get_logo_url(podcast, scaled_logo_size)

    return {
        "url": url,
        "title": podcast.title,
        "description": podcast.description,
        "subscribers": subscribers,
        "subscribers_last_week": last_subscribers,
        "logo_url": podcast.logo_url,
        "scaled_logo_url": 'http://%s%s' % (domain, scaled_logo_url),
        "website": podcast.link,
        "mygpo_link": 'http://%s%s' % (domain, get_podcast_link_target(podcast)),
    }

def podcast_data(obj, domain, scaled_logo_size=64):
    if obj is None:
        raise ValueError('podcast should not be None')

    if isinstance(obj, Podcast):
        podcast = obj
    elif isinstance(obj, PodcastGroup):
        podcast = obj.get_podcast()

    subscribers = obj.subscriber_count()
    last_subscribers = obj.prev_subscriber_count()

    scaled_logo_url = obj.get_logo_url(scaled_logo_size)

    return {
        "url": podcast.url,
        "title": podcast.title,
        "description": podcast.description,
        "subscribers": subscribers,
        "subscribers_last_week": last_subscribers,
        "logo_url": podcast.logo_url,
        "scaled_logo_url": 'http://%s%s' % (domain, scaled_logo_url),
        "website": podcast.link,
        "mygpo_link": 'http://%s%s' % (domain, get_podcast_link_target(obj)),
        }

def save_podcast(request, podcast):
    twitter = normalize_twitter(request.POST.get('twitter', ''))
    podcast.twitter = twitter
    podcast.save()
    messages.success(request, _('Data updated'))
    url = get_podcast_link_target(podcast, 'podcast-publisher-detail')
    return HttpResponseRedirect(url)

def add_tag(request, podcast):

    tag_str = request.GET.get('tag', '')
    if not tag_str:
        return HttpResponseBadRequest()

    user = request.user

    tags = tag_str.split(',')
    tags = map(str.strip, tags)

    ContentType.objects.get_for_model(podcast)

    for tag in tags:
        Tag.objects.get_or_create(
            tag=tag,
            source=Tag.USER,
            user=user,
            content_type=ContentType.objects.get_for_model(podcast),
            object_id=podcast.id,
        )

    if request.GET.get('next', '') == 'mytags':
        return HttpResponseRedirect('/tags/')

    return HttpResponseRedirect(get_podcast_link_target(podcast))

def remove_tag(request, podcast):

    tag_str = request.GET.get('tag', '')
    if not tag_str:
        return HttpResponseBadRequest()

    user = request.user

    tags = tag_str.split(',')
    tags = list(map(str.strip, tags))

    ContentType.objects.get_for_model(podcast)

    Tag.objects.filter(
        tag__in=tags,
        source=Tag.USER,
        user=user,
        content_type=ContentType.objects.get_for_model(podcast),
        object_id=podcast.id,
    ).delete()

    if request.GET.get('next', '') == 'mytags':
        return HttpResponseRedirect('/tags/')

    return HttpResponseRedirect(get_podcast_link_target(podcast))

def subscribe(request, podcast):

    if request.method == 'POST':

        # multiple UIDs from the /podcast/<slug>/subscribe
        device_uids = [k for (k,v) in request.POST.items() if k==v]

        # single UID from /podcast/<slug>
        if 'targets' in request.POST:
            devices = request.POST.get('targets')
            devices = devices.split(',')
            device_uids.extend(devices)

        for uid in device_uids:
            try:
                device = request.user.client_set.get(uid=uid)
                subscribe_podcast(podcast, request.user, device)

            except Client.DoesNotExist as e:
                messages.error(request, str(e))

        return HttpResponseRedirect(get_podcast_link_target(podcast))

    targets = get_subscribe_targets(podcast, request.user)

    return render(request, 'subscribe.html', {
        'targets': targets,
        'podcast': podcast,
    })

def subscribe(request, podcast):

    if request.method == 'POST':
        form = SyncForm(request.POST)

        try:
            device = request.user.get_device_by_uid(form.get_target())
            podcast.subscribe(request.user, device)

        except (SubscriptionException, DeviceDoesNotExist) as e:
            messages.error(request, str(e))

        return HttpResponseRedirect(get_podcast_link_target(podcast))


    request.user.sync_all()

    targets = podcast.subscribe_targets(request.user)

    form = SyncForm()
    form.set_targets(targets, _('Choose a device:'))

    return render(request, 'subscribe.html', {
        'podcast': podcast,
        'can_subscribe': len(targets) > 0,
        'form': form
    })

def podcast_link(podcast, title=None):
    """ Returns the link for a single Podcast """

    title = title or podcast.display_title

    title = strip_tags(title)

    return format_html('<a href="{target}" title="{title}">{title}</a>',
        target=get_podcast_link_target(podcast), title=title)

def update_podcast(request, podcast):

    if not check_publisher_permission(request.user, podcast):
        return HttpResponseForbidden()

    update_podcasts( [podcast] )

    url = get_podcast_link_target(podcast, 'podcast-publisher-detail')
    return HttpResponseRedirect(url)

def set_public(request, podcast, public):
    settings, created = UserSettings.objects.get_or_create(
        user=request.user,
        content_type=ContentType.objects.get_for_model(podcast),
        object_id=podcast.pk,
    )
    settings.set_wksetting(PUBLIC_SUB_PODCAST, public)
    settings.save()
    return HttpResponseRedirect(get_podcast_link_target(podcast))

def podcast_link(podcast, title=None):
    """ Returns the link for a single Podcast """

    title = title or getattr(podcast, 'display_title', None) or podcast.title

    title = strip_tags(title)

    return '<a href="%(target)s" title="%(title)s">%(title)s</a>' % \
        dict(target=get_podcast_link_target(podcast), title=title)

def search_podcast(request):
    form = SearchPodcastForm(request.POST)
    if form.is_valid():
        podcast_url = form.cleaned_data['url']
        podcast = get_objet_or_404(Podcast, urls__url=podcast_url)
        url = get_podcast_link_target(podcast, 'podcast-publisher-detail')
    else:
        url = reverse('publisher')

    return HttpResponseRedirect(url)

def opengraph_podcast(podcast):
    s = OPENGRAPH_STR % dict(
        title     = podcast.title,
        type      = 'episode',
        image     = 'http://gpodder.net%s' % podcast.get_logo_url(PODCAST_LOGO_BIG_SIZE),
        url       = 'http://gpodder.net%s' % get_podcast_link_target(podcast),
        site_name = 'gpodder.net',
        admins    = '0'
    )
    return mark_safe(s)

def update_podcast(request, podcast):

    if not check_publisher_permission(request.user, podcast):
        return HttpResponseForbidden()

    update_podcasts.delay([podcast.url])
    messages.success(request, _('The update has been scheduled. It might take some time until the results are visible.'))

    url = get_podcast_link_target(podcast, 'podcast-publisher-detail')
    return HttpResponseRedirect(url)

    def _decorator(request, slug_id, *args, **kwargs):
        podcast = podcast_for_slug_id(slug_id)

        if podcast is None:
            raise Http404

        # redirect when Id or a merged (non-cannonical) slug is used
        if podcast.slug and slug_id != podcast.slug:
            return HttpResponseRedirect(get_podcast_link_target(podcast))

        return f(request, podcast, *args, **kwargs)

def remove_tag(request, podcast):
    podcast_state = podcast_state_for_user_podcast(request.user, podcast)

    tag_str = request.GET.get('tag', '')
    if not tag_str:
        return HttpResponseBadRequest()

    remove_podcast_tags(podcast_state, tag_str)

    if request.GET.get('next', '') == 'mytags':
        return HttpResponseRedirect('/tags/')

    return HttpResponseRedirect(get_podcast_link_target(podcast))

def search_podcast(request):
    form = SearchPodcastForm(request.POST)
    if form.is_valid():
        url = form.cleaned_data['url']

        podcast = podcast_for_url(url)
        if not podcast:
            raise Http404

        url = get_podcast_link_target(podcast, 'podcast-publisher-detail')
    else:
        url = reverse('publisher')

    return HttpResponseRedirect(url)

def subscribe_url(request):
    url = request.GET.get('url', None)

    if not url:
        raise Http404('http://my.gpodder.org/subscribe?url=http://www.example.com/podcast.xml')

    url = sanitize_url(url)

    if url == '':
        raise Http404('Please specify a valid url')

    podcast = Podcast.for_url(url, create=True)

    return HttpResponseRedirect(get_podcast_link_target(podcast, 'subscribe'))

def subscribe_url(request):
    url = request.GET.get('url', None)

    if not url:
        raise Http404('http://my.gpodder.org/subscribe?url=http://www.example.com/podcast.xml')

    url = normalize_feed_url(url)

    if not url:
        raise Http404('Please specify a valid url')

    podcast = Podcast.objects.get_or_create_for_url(url)

    return HttpResponseRedirect(get_podcast_link_target(podcast, 'subscribe'))