from __future__ import unicode_literals
from future.builtins import str

from copy import copy

from django.contrib import admin
from django.contrib.messages import info
from django.http import HttpResponseRedirect
from django.utils.translation import ugettext_lazy as _
from django.utils.encoding import force_text

from mezzanine.core.admin import BaseTranslationModelAdmin
from mezzanine.conf import settings
from mezzanine.conf.models import Setting
from mezzanine.conf.forms import SettingsForm
from mezzanine.utils.static import static_lazy as static
from mezzanine.utils.urls import admin_url


class SettingsAdmin(admin.ModelAdmin):
    """
    Admin class for settings model. Redirect add/change views to the
    list view where a single form is rendered for editing all settings.
    """

    class Media(BaseTranslationModelAdmin.Media):
        css = copy(BaseTranslationModelAdmin.Media.css)
        css["all"] += (static("mezzanine/css/admin/settings.css"),)
        js = [js.replace(str(static("tabbed_translation_fields.js")),
                         str(static("tabbed_translatable_settings.js")))
              for js in BaseTranslationModelAdmin.Media.js]

    def changelist_redirect(self):
        changelist_url = admin_url(Setting, "changelist")
        return HttpResponseRedirect(changelist_url)

    def add_view(self, *args, **kwargs):
        return self.changelist_redirect()

    def change_view(self, *args, **kwargs):
        return self.changelist_redirect()

    def changelist_view(self, request, extra_context=None):
        if extra_context is None:
            extra_context = {}
        settings_form = SettingsForm(request.POST or None)
        if settings_form.is_valid():
            settings_form.save()
            settings.clear_cache()
            info(request, _("Settings were successfully updated."))
            return self.changelist_redirect()
        extra_context["settings_form"] = settings_form
        extra_context["title"] = u"%s %s" % (
            _("Change"), force_text(Setting._meta.verbose_name_plural))
        return super(SettingsAdmin, self).changelist_view(request,
                                                            extra_context)


admin.site.register(Setting, SettingsAdmin)
