from __future__ import absolute_import

import logging

from django.db import models
from django.utils.translation import ugettext_lazy as _
from django.utils.translation import ugettext
from django.contrib.contenttypes.models import ContentType
from django.contrib.contenttypes import generic
from django.core.exceptions import PermissionDenied
from django.core.urlresolvers import reverse
from django.core.exceptions import ObjectDoesNotExist
from django.shortcuts import get_object_or_404
from django.template.defaultfilters import capfirst

from permissions.models import StoredPermission

from .managers import AccessEntryManager, DefaultAccessEntryManager

logger = logging.getLogger(__name__)

        
class AccessEntry(models.Model):
    '''
    Model that hold the permission, object, actor relationship
    '''
    
    permission = models.ForeignKey(StoredPermission, verbose_name=_(u'permission'))

    holder_type = models.ForeignKey(
        ContentType,
        related_name='access_holder',
        limit_choices_to={'model__in': ('user', 'group', 'role')}
    )
    holder_id = models.PositiveIntegerField()
    holder_object = generic.GenericForeignKey(
        ct_field='holder_type',
        fk_field='holder_id'
    )

    content_type = models.ForeignKey(
        ContentType,
        related_name='object_content_type'
    )
    object_id = models.PositiveIntegerField()
    content_object = generic.GenericForeignKey(
        ct_field='content_type',
        fk_field='object_id'
    )

    objects = AccessEntryManager()

    class Meta:
        verbose_name = _(u'access entry')
        verbose_name_plural = _(u'access entries')

    def __unicode__(self):
        return u'%s: %s' % (self.content_type, self.content_object)


class DefaultAccessEntry(models.Model):
    '''
    Model that holds the permission, class, actor relationship, that will
    be added upon the creation of an instance of said class
    '''
    
    @classmethod
    def get_classes(cls):
        return [AccessObjectClass.encapsulate(cls) for cls in _class_permissions.keys()]

    permission = models.ForeignKey(StoredPermission, verbose_name=_(u'permission'))

    holder_type = models.ForeignKey(
        ContentType,
        limit_choices_to={'model__in': ('user', 'group', 'role')},
        related_name='default_access_entry_holder'
    )
    holder_id = models.PositiveIntegerField()
    holder_object = generic.GenericForeignKey(
        ct_field='holder_type',
        fk_field='holder_id'
    )

    content_type = models.ForeignKey(
        ContentType,
        related_name='default_access_entry_class'
    )

    objects = DefaultAccessEntryManager()

    class Meta:
        verbose_name = _(u'default access entry')
        verbose_name_plural = _(u'default access entries')

    def __unicode__(self):
        return u'%s: %s' % (self.content_type, self.content_object)