# Re2o est un logiciel d'administration développé initiallement au rezometz. Il
# se veut agnostique au réseau considéré, de manière à être installable en
# quelques clics.
#
# Copyright © 2020  Gabriel Détraz
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

# App de gestion des machines pour re2o
# Gabriel Détraz, Augustin Lemesle
# Gplv2
"""
Utils for preferences
"""

from __future__ import unicode_literals

from django.core.cache import cache
from django.db import models


class PreferencesModel(models.Model):
    """ Base object for the Preferences objects
    Defines methods to handle the cache of the settings (they should
    not change a lot) """

    @classmethod
    def set_in_cache(cls):
        """ Save the preferences in a server-side cache """
        instance, _created = cls.objects.get_or_create()
        cache.set(cls().__class__.__name__.lower(), instance, None)
        return instance

    @classmethod
    def get_cached_value(cls, key):
        """ Get the preferences from the server-side cache """
        instance = cache.get(cls().__class__.__name__.lower())
        if instance is None:
            instance = cls.set_in_cache()
        return getattr(instance, key)

    class Meta:
        abstract = True