from __future__ import unicode_literals

from django import apps
from django.db.models.signals import post_migrate
from django.db.utils import DatabaseError
from django.dispatch import receiver
from django.utils.translation import ugettext_lazy as _

from common.utils import encapsulate
from navigation.api import register_links, register_model_list_columns
from project_tools.api import register_tool

from .classes import Property, PropertyNamespace
from .links import link_menu_link, link_namespace_details, link_namespace_list
from .models import Installation


def create_installation_instance(sender, **kwargs):
    if kwargs.get('app') == 'installation':
        Installation.objects.get_or_create()


class InstallationApp(apps.AppConfig):
    name = 'installation'
    verbose_name = _('Installation')

    def ready(self):
        post_migrate.connect(create_installation_instance, dispatch_uid='create_installation_instance')

        register_model_list_columns(PropertyNamespace, [
            {
                'name': _('Label'),
                'attribute': 'label'
            },
            {
                'name': _('Items'),
                'attribute': encapsulate(lambda entry: len(entry.get_properties()))
            }
        ])

        register_model_list_columns(Property, [
            {
                'name': _('Label'),
                'attribute': 'label'
            },
            {
                'name': _('Value'),
                'attribute': 'value'
            }
        ])

        register_links(PropertyNamespace, [link_namespace_details])
        register_links(['installation:namespace_list', PropertyNamespace], [link_namespace_list], menu_name='secondary_menu')
        register_tool(link_menu_link)