"""
    list_filter = (('article__product', SearchableFilter),
                   ('article', SearchableFilter))

    def lookup_allowed(self, lookup, value):
        return lookup in [
            'article__id__exact',
            'article__product__id__exact',
        ] or super(LicenseAdmin, self).lookup_allowed(lookup, value)
"""

from django.contrib.admin import RelatedFieldListFilter
from django.core.urlresolvers import reverse


class SearchableFilter(RelatedFieldListFilter):
    template = 'admin/searchable_filter.html'

    def choices(self, cl):
        ch = list(super(SearchableFilter, self).choices(cl))
        return ch[:1] + list(sorted(ch[1:], key=lambda x: x['display'].strip()))


def admin_link(obj, name=None):
    if isinstance(obj, str):
        def _admin_link(instance):
            from django.db.models import Manager
            instance = getattr(instance, obj)
            if isinstance(instance, Manager):
                instance = instance.all()
            return admin_link(instance)
        _admin_link.allow_tags = True
        _admin_link.short_description = str(obj).replace('_', ' ').capitalize()
        return _admin_link
    if hasattr(obj, '__iter__'):
        return '<br>'.join(map(admin_link, obj))
    if obj:
        return '<a class="changelink" style="color: #334" href="%s">%s</a>' % (
            reverse('admin:%s_%s_change' % (
                obj._meta.app_label,
                obj._meta.module_name,
            ), args=(
                obj.pk,
            )),
            name or obj)