import functools

from django.contrib.admin import helpers
from django.template.response import TemplateResponse


def action_form(form_class=None):
    def decorator(func):
        @functools.wraps(func)
        def wrapper(self, request, queryset):
            form = form_class()

            if 'confirm' in request.POST and request.POST:
                form = form_class(request.POST, request.FILES)
                if form.is_valid():
                    obj_count = func(self, request, queryset, form)
                    self.message_user(request, '%s objects updated' % obj_count)
                    return None

            context = dict(
                self.admin_site.each_context(request),
                title=form_class.title,
                action=func.__name__,
                opts=self.model._meta,
                queryset=queryset, form=form,
                action_checkbox_name=helpers.ACTION_CHECKBOX_NAME)

            return TemplateResponse(request, 'admin/form_action_confirmation.html', context)

        wrapper.short_description = form_class.title

        return wrapper

    return decorator