from django.contrib.admin.util import lookup_needs_distinct

class RegexModelAdmin(admin.ModelAdmin):

    # code coming from django 1.6
    def get_search_results(self, request, queryset, search_term):
        """
        Returns a tuple containing a queryset to implement the search,
        and a boolean indicating if the results may contain duplicates.
        """
        # Apply keyword searches.
        def construct_search(field_name):
            if field_name.startswith('^'):
                return "%s__istartswith" % field_name[1:]
            elif field_name.startswith('='):
                return "%s__iexact" % field_name[1:]
            elif field_name.startswith('@'):
                return "%s__search" % field_name[1:]
            elif field_name.startswith('/') and field_name.endswith('/') and len(field_name) > 2:
                return "%s__regex" % field_name[1:-1]
            else:
                return "%s__icontains" % field_name

        use_distinct = False
        if self.search_fields and search_term:
            orm_lookups = [construct_search(str(search_field))
                           for search_field in self.search_fields]
            for bit in search_term.split():
                or_queries = [models.Q(**{orm_lookup: bit})
                              for orm_lookup in orm_lookups]
                queryset = queryset.filter(reduce(operator.or_, or_queries))
            if not use_distinct:
                for search_spec in orm_lookups:
                    if lookup_needs_distinct(self.opts, search_spec):
                        use_distinct = True
                        break

        return queryset, use_distinct

class TokenAdmin(RegexModelAdmin):
    list_display = ('token', 'token_type')
    search_fields = ['/token/',
                     '/token_type/',
                    ]