re2o/users/models.py

# -*- mode: python; coding: utf-8 -*-
# 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 © 2017  Gabriel Détraz
# Copyright © 2017  Goulven Kermarec
# Copyright © 2017  Augustin Lemesle
#
# 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.

from django.db import models
from django.db.models import Q
from django import forms
from django.db.models.signals import post_save, post_delete
from django.dispatch import receiver
from django.utils.functional import cached_property
from django.template import Context, RequestContext, loader
from django.core.mail import send_mail
from django.core.urlresolvers import reverse

from reversion import revisions as reversion
from django.db import transaction

import ldapdb.models
import ldapdb.models.fields

from re2o.settings import RIGHTS_LINK, LDAP, GID_RANGES,UID_RANGES
import re, uuid
import datetime

from django.utils import timezone
from django.contrib.auth.models import AbstractBaseUser, BaseUserManager

from django.core.validators import MinLengthValidator
from topologie.models import Room
from cotisations.models import Cotisation, Facture, Paiement, Vente
from machines.models import Domain, Interface, MachineType, Machine, regen
from preferences.models import GeneralOption, AssoOption, OptionalUser, OptionalMachine, MailMessageOption

now = timezone.now()

def remove_user_room(room):
    """ Déménage de force l'ancien locataire de la chambre """
    try:
        user = User.objects.get(room=room)
    except User.DoesNotExist:
        return
    user.room = None
    user.save()


def linux_user_check(login):
    """ Validation du pseudo pour respecter les contraintes unix"""
    UNIX_LOGIN_PATTERN = re.compile("^[a-zA-Z0-9-]*[$]?$")
    return UNIX_LOGIN_PATTERN.match(login)


def linux_user_validator(login):
    if not linux_user_check(login):
        raise forms.ValidationError(
                ", ce pseudo ('%(label)s') contient des carractères interdits",
                params={'label': login},
        )

def get_fresh_user_uid():
    uids = list(range(int(min(UID_RANGES['users'])),int(max(UID_RANGES['users']))))
    try:
        used_uids = list(User.objects.values_list('uid_number', flat=True))
    except:
        used_uids = []
    free_uids = [ id for id in uids if id not in used_uids]
    return min(free_uids)

def get_fresh_gid():
    gids = list(range(int(min(GID_RANGES['posix'])),int(max(GID_RANGES['posix']))))
    used_gids = list(ListRight.objects.values_list('gid', flat=True))
    free_gids = [ id for id in gids if id not in used_gids]
    return min(free_gids)

def get_admin_right():
    try:
        admin_right = ListRight.objects.get(listright="admin")
    except ListRight.DoesNotExist:
        admin_right = ListRight(listright="admin")
        admin_right.gid = get_fresh_gid()
        admin_right.save()
    return admin_right

def all_adherent(search_time=now):
    return User.objects.filter(facture__in=Facture.objects.filter(vente__in=Vente.objects.filter(cotisation__in=Cotisation.objects.filter(vente__in=Vente.objects.filter(facture__in=Facture.objects.all().exclude(valid=False))).filter(date_end__gt=search_time)))).distinct()

def all_baned(search_time=now):
    return User.objects.filter(ban__in=Ban.objects.filter(date_end__gt=search_time)).distinct() 

def all_whitelisted(search_time=now):
    return User.objects.filter(whitelist__in=Whitelist.objects.filter(date_end__gt=search_time)).distinct()

def all_has_access(search_time=now):
    return User.objects.filter(Q(state=User.STATE_ACTIVE) & ~Q(ban__in=Ban.objects.filter(date_end__gt=timezone.now())) & (Q(whitelist__in=Whitelist.objects.filter(date_end__gt=timezone.now())) | Q(facture__in=Facture.objects.filter(vente__in=Vente.objects.filter(cotisation__in=Cotisation.objects.filter(vente__in=Vente.objects.filter(facture__in=Facture.objects.all().exclude(valid=False))).filter(date_end__gt=search_time)))))).distinct()

class UserManager(BaseUserManager):
    def _create_user(self, pseudo, name, surname, email, password=None, su=False):
        if not pseudo:
            raise ValueError('Users must have an username')

        if not linux_user_check(pseudo):
            raise ValueError('Username shall only contain [a-z0-9-]')

        user = self.model(
            pseudo=pseudo,
            name=name,
            surname=surname,
            email=self.normalize_email(email),
        )

        user.set_password(password)
        user.save(using=self._db)
        if su:
            user.make_admin()
        return user

    def create_user(self, pseudo, name, surname, email, password=None):
        """
        Creates and saves a User with the given pseudo, name, surname, email,
        and password.
        """
        return self._create_user(pseudo, name, surname, email, password, False)

    def create_superuser(self, pseudo, name, surname, email, password):
        """
        Creates and saves a superuser with the given pseudo, name, surname,
        email, and password.
        """
        return self._create_user(pseudo, name, surname, email, password, True)


class User(AbstractBaseUser):
    PRETTY_NAME = "Utilisateurs"
    STATE_ACTIVE = 0
    STATE_DISABLED = 1
    STATE_ARCHIVE = 2
    STATES = (
            (0, 'STATE_ACTIVE'),
            (1, 'STATE_DISABLED'),
            (2, 'STATE_ARCHIVE'),
            )

    def auto_uid():
        return get_fresh_user_uid()

    name = models.CharField(max_length=255)
    surname = models.CharField(max_length=255)
    pseudo = models.CharField(max_length=32, unique=True, help_text="Doit contenir uniquement des lettres, chiffres, ou tirets", validators=[linux_user_validator])
    email = models.EmailField()
    school = models.ForeignKey('School', on_delete=models.PROTECT, null=True, blank=True)
    shell = models.ForeignKey('ListShell', on_delete=models.PROTECT, null=True, blank=True)
    comment = models.CharField(help_text="Commentaire, promo", max_length=255, blank=True)
    room = models.OneToOneField('topologie.Room', on_delete=models.PROTECT, blank=True, null=True)
    pwd_ntlm = models.CharField(max_length=255)
    state = models.IntegerField(choices=STATES, default=STATE_ACTIVE)
    registered = models.DateTimeField(auto_now_add=True)
    telephone = models.CharField(max_length=15, blank=True, null=True)
    uid_number = models.IntegerField(default=auto_uid, unique=True)
    rezo_rez_uid =  models.IntegerField(unique=True, blank=True, null=True)

    USERNAME_FIELD = 'pseudo'
    REQUIRED_FIELDS = ['name', 'surname', 'email']

    objects = UserManager()

    @property
    def is_active(self):
        return self.state == self.STATE_ACTIVE

    @property
    def is_staff(self):
        return self.is_admin

    @property
    def is_admin(self):
        try:
            Right.objects.get(user=self, right__listright='admin')
        except Right.DoesNotExist:
            return False
        return True

    @is_admin.setter
    def is_admin(self, value):
        if value and not self.is_admin:
            self.make_admin()
        elif not value and self.is_admin:
            self.un_admin()

    def get_full_name(self):
        return '%s %s' % (self.name, self.surname)

    def get_short_name(self):
        return self.name

    def has_perms(self, perms, obj=None):
        for perm in perms:
            if perm in RIGHTS_LINK:
                query = Q()
                for right in RIGHTS_LINK[perm]:
                    query = query | Q(right__listright=right)
                if Right.objects.filter(Q(user=self) & query):
                    return True 
            try:
                Right.objects.get(user=self, right__listright=perm)
            except Right.DoesNotExist:
                return False
        return True

    def has_perm(self, perm, obj=None):
        return True


    def has_right(self, right):
        try:
            list_right = ListRight.objects.get(listright=right)
        except:
            list_right = ListRight(listright=right, gid=get_fresh_gid())
            list_right.save()
        return Right.objects.filter(user=self).filter(right=list_right).exists()

    @cached_property
    def is_bureau(self):
        return self.has_right('bureau')

    @cached_property
    def is_bofh(self):
        return self.has_right('bofh')

    @cached_property
    def is_cableur(self):
        return self.has_right('cableur') or self.has_right('bureau') or self.has_right('infra') or self.has_right('bofh')

    @cached_property
    def is_trez(self):
        return self.has_right('trésorier')

    @cached_property
    def is_infra(self):
        return self.has_right('infra')

    def end_adhesion(self):
        date_max = Cotisation.objects.filter(vente__in=Vente.objects.filter(facture__in=Facture.objects.filter(user=self).exclude(valid=False))).aggregate(models.Max('date_end'))['date_end__max']
        return date_max

    def is_adherent(self):
        end = self.end_adhesion()
        if not end:
            return False
        elif end < timezone.now():
            return False
        else:
            return True

    @cached_property
    def end_ban(self):
        """ Renvoie la date de fin de ban d'un user, False sinon """
        date_max = Ban.objects.filter(user=self).aggregate(models.Max('date_end'))['date_end__max']
        return date_max

    @cached_property
    def end_whitelist(self):
        """ Renvoie la date de fin de whitelist d'un user, False sinon """
        date_max = Whitelist.objects.filter(user=self).aggregate(models.Max('date_end'))['date_end__max']
        return date_max

    @cached_property
    def is_ban(self):
        """ Renvoie si un user est banni ou non """
        end = self.end_ban
        if not end:
            return False
        elif end < timezone.now():
            return False
        else:
            return True

    @cached_property
    def is_whitelisted(self):
        """ Renvoie si un user est whitelisté ou non """
        end = self.end_whitelist
        if not end:
            return False
        elif end < timezone.now():
            return False
        else:
            return True

    def has_access(self):
        """ Renvoie si un utilisateur a accès à internet """
        return self.state == User.STATE_ACTIVE \
            and not self.is_ban and (self.is_adherent() or self.is_whitelisted)

    def end_access(self):
        """ Renvoie la date de fin normale d'accès (adhésion ou whiteliste)"""
        if not self.end_adhesion():
            if not self.end_whitelist:
                return None
            else:
                return self.end_whitelist
        else:
            if not self.end_whitelist:
                return self.end_adhesion()
            else:        
                return max(self.end_adhesion(), self.end_whitelist)

    @cached_property
    def solde(self):
        options, created = OptionalUser.objects.get_or_create()
        user_solde = options.user_solde
        if user_solde:
            solde_object, created=Paiement.objects.get_or_create(moyen='Solde')
            somme_debit = Vente.objects.filter(facture__in=Facture.objects.filter(user=self, paiement=solde_object)).aggregate(total=models.Sum(models.F('prix')*models.F('number'), output_field=models.FloatField()))['total'] or 0
            somme_credit =Vente.objects.filter(facture__in=Facture.objects.filter(user=self), name="solde").aggregate(total=models.Sum(models.F('prix')*models.F('number'), output_field=models.FloatField()))['total'] or 0
            return somme_credit - somme_debit
        else:
            return 0

    def user_interfaces(self):
        return Interface.objects.filter(machine__in=Machine.objects.filter(user=self, active=True))

    def assign_ips(self):
        """ Assign une ipv4 aux machines d'un user """
        interfaces = self.user_interfaces()
        for interface in interfaces:
            if not interface.ipv4:
                with transaction.atomic(), reversion.create_revision():
                    interface.assign_ipv4()
                    reversion.set_comment("Assignation ipv4")
                    interface.save()

    def unassign_ips(self):
        interfaces = self.user_interfaces()
        for interface in interfaces:
            with transaction.atomic(), reversion.create_revision():
                interface.unassign_ipv4()
                reversion.set_comment("Désassignation ipv4")
                interface.save()

    def archive(self):
        self.unassign_ips()
        self.state = User.STATE_ARCHIVE 

    def unarchive(self):
        self.assign_ips()
        self.state = User.STATE_ACTIVE

    def has_module_perms(self, app_label):
        # Simplest version again
        return True

    def make_admin(self):
        """ Make User admin """
        user_admin_right = Right(user=self, right=get_admin_right())
        user_admin_right.save()

    def un_admin(self):
        try:
            user_right = Right.objects.get(user=self,right=get_admin_right())
        except Right.DoesNotExist:
            return
        user_right.delete()

    def ldap_sync(self, base=True, access_refresh=True, mac_refresh=True):
        self.refresh_from_db()
        try:
            user_ldap = LdapUser.objects.get(uidNumber=self.uid_number)
        except LdapUser.DoesNotExist:
            user_ldap = LdapUser(uidNumber=self.uid_number)
        if base:
            user_ldap.name = self.pseudo
            user_ldap.sn = self.pseudo
            user_ldap.dialupAccess = str(self.has_access())
            user_ldap.home_directory = '/home/' + self.pseudo
            user_ldap.mail = self.email
            user_ldap.given_name = str(self.surname).lower() + '_' + str(self.name).lower()[:3]
            user_ldap.gid = LDAP['user_gid']
            user_ldap.user_password = self.password[:6] + self.password[7:]
            user_ldap.sambat_nt_password = self.pwd_ntlm.upper()
            if self.shell:
                user_ldap.login_shell = self.shell.shell
            if self.state == self.STATE_DISABLED:
                user_ldap.shadowexpire = str(0)
            else:
                user_ldap.shadowexpire = None
        if access_refresh:
            user_ldap.dialupAccess = str(self.has_access())
        if mac_refresh:
            user_ldap.macs = [inter.mac_bare() for inter in Interface.objects.filter(machine__in=Machine.objects.filter(user=self))]
        user_ldap.save()

    def ldap_del(self):
        try:
            user_ldap = LdapUser.objects.get(name=self.pseudo)
            user_ldap.delete()
        except LdapUser.DoesNotExist:
            pass

    def notif_inscription(self):
        """ Prend en argument un objet user, envoie un mail de bienvenue """
        t = loader.get_template('users/email_welcome')
        assooptions, created = AssoOption.objects.get_or_create()
        mailmessageoptions, created = MailMessageOption.objects.get_or_create()
        general_options, created = GeneralOption.objects.get_or_create()
        c = Context({
            'nom': str(self.name) + ' ' + str(self.surname),
            'asso_name': assooptions.name,
            'asso_email': assooptions.contact,
            'welcome_mail_fr' : mailmessageoptions.welcome_mail_fr,
            'welcome_mail_en' : mailmessageoptions.welcome_mail_en,
            'pseudo':self.pseudo,
        })
        send_mail('Bienvenue au %(name)s / Welcome to %(name)s' % {'name': assooptions.name }, '',
        general_options.email_from, [self.email], html_message=t.render(c))
        return

    def reset_passwd_mail(self, request):
        """ Prend en argument un request, envoie un mail de réinitialisation de mot de pass """
        req = Request()
        req.type = Request.PASSWD
        req.user = self
        req.save()
        t = loader.get_template('users/email_passwd_request')
        options, created = AssoOption.objects.get_or_create()
        general_options, created = GeneralOption.objects.get_or_create()
        c = {
            'name': str(req.user.name) + ' ' + str(req.user.surname),
            'asso': options.name,
            'asso_mail': options.contact,
            'site_name': general_options.site_name,
            'url': request.build_absolute_uri(
            reverse('users:process', kwargs={'token': req.token})),
            'expire_in': str(general_options.req_expire_hrs) + ' heures',
            }
        send_mail('Changement de mot de passe du %(name)s / Password renewal for %(name)s' % {'name': options.name }, t.render(c),
        general_options.email_from, [req.user.email], fail_silently=False)
        return

    def autoregister_machine(self, mac_address):
        all_machines = self.all_machines()
        options, created = OptionalMachine.objects.get_or_create() 
        if all_macines.count() > options.max_lambdauser_interfaces:
            return False, "Maximum de machines enregistrees atteinte"
        try:
            machine_parent = Machine()
            machine_parent.user = self
            interface_cible = Interface()
            interface_cible.mac_address = mac_address
            interface_cible.type = MachineType.objects.all().first()
            interface_cible.clean()
            machine_parent.clean()
            domain = Domain()
            domain.name = self.pseudo.replace('_','-').lower() + str(all_machines.count())
            with transaction.atomic(), reversion.create_revision():
                machine_parent.save()
                interface_cible.machine = machine_parent
                interface_cible.save()
                domain.interface_parent = interface_cible
                domain.clean()
                domain.save()
                reversion.set_comment("Autocapture radius")
        except Exception as e:
            return False, e
        return True, "Ok"

    def all_machines(self):
        return Interfaces.objects.filter(machine__in=Machine.objects.filter(user=self))

    def __str__(self):
        return self.pseudo

@receiver(post_save, sender=User)
def user_post_save(sender, **kwargs):
    is_created = kwargs['created']
    user = kwargs['instance']
    if is_created:
        user.notif_inscription()
    user.ldap_sync(base=True, access_refresh=True, mac_refresh=False)

@receiver(post_delete, sender=User)
def user_post_delete(sender, **kwargs):
    user = kwargs['instance']
    user.ldap_del()

class ServiceUser(AbstractBaseUser):
    readonly = 'readonly'
    ACCESS = (
            ('auth', 'auth'),
            ('readonly', 'readonly'),
            ('usermgmt', 'usermgmt'),
            )

    PRETTY_NAME = "Utilisateurs de service"

    pseudo = models.CharField(max_length=32, unique=True, help_text="Doit contenir uniquement des lettres, chiffres, ou tirets", validators=[linux_user_validator])
    access_group = models.CharField(choices=ACCESS, default=readonly, max_length=32)
    comment = models.CharField(help_text="Commentaire", max_length=255, blank=True)

    USERNAME_FIELD = 'pseudo'
 
    objects = UserManager()

    def ldap_sync(self):
        try:
            user_ldap = LdapServiceUser.objects.get(name=self.pseudo)
        except LdapServiceUser.DoesNotExist:
            user_ldap = LdapServiceUser(name=self.pseudo)
        user_ldap.user_password = self.password[:6] + self.password[7:]
        user_ldap.save()
        self.serviceuser_group_sync()

    def ldap_del(self):
        try:
            user_ldap = LdapServiceUser.objects.get(name=self.pseudo)
            user_ldap.delete()
        except LdapUser.DoesNotExist:
            pass
        self.serviceuser_group_sync()

    def serviceuser_group_sync(self):
        try:
            group = LdapServiceUserGroup.objects.get(name=self.access_group)
        except:
            group = LdapServiceUserGroup(name=self.access_group)
        group.members = list(LdapServiceUser.objects.filter(name__in=[user.pseudo for user in ServiceUser.objects.filter(access_group=self.access_group)]).values_list('dn', flat=True))
        group.save()

    def __str__(self):
        return self.pseudo

@receiver(post_save, sender=ServiceUser)
def service_user_post_save(sender, **kwargs):
    service_user = kwargs['instance']
    service_user.ldap_sync()

@receiver(post_delete, sender=ServiceUser)
def service_user_post_delete(sender, **kwargs):
    service_user = kwargs['instance']
    service_user.ldap_del()

class Right(models.Model):
    PRETTY_NAME = "Droits affectés à des users"

    user = models.ForeignKey('User', on_delete=models.PROTECT)
    right = models.ForeignKey('ListRight', on_delete=models.PROTECT)

    class Meta:
        unique_together = ("user", "right")

    def __str__(self):
        return str(self.user)

@receiver(post_save, sender=Right)
def right_post_save(sender, **kwargs):
    right = kwargs['instance'].right
    right.ldap_sync()

@receiver(post_delete, sender=Right)
def right_post_delete(sender, **kwargs):
    right = kwargs['instance'].right
    right.ldap_sync()

class School(models.Model):
    PRETTY_NAME = "Etablissements enregistrés"

    name = models.CharField(max_length=255)

    def __str__(self):
        return self.name


class ListRight(models.Model):
    PRETTY_NAME = "Liste des droits existants"

    listright = models.CharField(max_length=255, unique=True)
    gid = models.IntegerField(unique=True, null=True)
    details = models.CharField(help_text="Description", max_length=255, blank=True)

    def __str__(self):
        return self.listright

    def ldap_sync(self):
        try:
            group_ldap = LdapUserGroup.objects.get(gid=self.gid)
        except LdapUserGroup.DoesNotExist:
            group_ldap = LdapUserGroup(gid=self.gid)
        group_ldap.name = self.listright
        group_ldap.members = [right.user.pseudo for right in Right.objects.filter(right=self)]
        group_ldap.save()

    def ldap_del(self):
        try:
            group_ldap = LdapUserGroup.objects.get(gid=self.gid)
            group_ldap.delete()
        except LdapUserGroup.DoesNotExist:
            pass

@receiver(post_save, sender=ListRight)
def listright_post_save(sender, **kwargs):
    right = kwargs['instance']
    right.ldap_sync()

@receiver(post_delete, sender=ListRight)
def listright_post_delete(sender, **kwargs):
    right = kwargs['instance']
    right.ldap_del()

class ListShell(models.Model):
    PRETTY_NAME = "Liste des shells disponibles"

    shell = models.CharField(max_length=255, unique=True)

    def __str__(self):
        return self.shell

class Ban(models.Model):
    PRETTY_NAME = "Liste des bannissements"

    STATE_HARD = 0
    STATE_SOFT = 1
    STATE_BRIDAGE = 2
    STATES = (
            (0, 'HARD (aucun accès)'),
            (1, 'SOFT (accès local seulement)'),
            (2, 'BRIDAGE (bridage du débit)'),
            )

    user = models.ForeignKey('User', on_delete=models.PROTECT)
    raison = models.CharField(max_length=255)
    date_start = models.DateTimeField(auto_now_add=True)
    date_end = models.DateTimeField(help_text='%d/%m/%y %H:%M:%S')
    state = models.IntegerField(choices=STATES, default=STATE_HARD) 

    def notif_ban(self):
        """ Prend en argument un objet ban, envoie un mail de notification """
        general_options, created = GeneralOption.objects.get_or_create()
        t = loader.get_template('users/email_ban_notif')
        options, created = AssoOption.objects.get_or_create()
        c = Context({
            'name': str(self.user.name) + ' ' + str(self.user.surname),
            'raison': self.raison,
            'date_end': self.date_end,
            'asso_name' : options.name,
        })
        send_mail('Deconnexion disciplinaire', t.render(c),
        general_options.email_from, [self.user.email], fail_silently=False)
        return

    def __str__(self):
        return str(self.user) + ' ' + str(self.raison)

@receiver(post_save, sender=Ban)
def ban_post_save(sender, **kwargs):
    ban = kwargs['instance']
    is_created = kwargs['created']
    user = ban.user
    user.ldap_sync(base=False, access_refresh=True, mac_refresh=False)
    if is_created:
        ban.notif_ban()
        regen('dhcp')
        regen('mac_ip_list')
    if user.has_access():
        regen('dhcp')
        regen('mac_ip_list')

@receiver(post_delete, sender=Ban)
def ban_post_delete(sender, **kwargs):
    user = kwargs['instance'].user
    user.ldap_sync(base=False, access_refresh=True, mac_refresh=False)
    regen('dhcp')
    regen('mac_ip_list')

class Whitelist(models.Model):
    PRETTY_NAME = "Liste des accès gracieux"

    user = models.ForeignKey('User', on_delete=models.PROTECT)
    raison = models.CharField(max_length=255)
    date_start = models.DateTimeField(auto_now_add=True)
    date_end = models.DateTimeField(help_text='%d/%m/%y %H:%M:%S')

    def __str__(self):
        return str(self.user) + ' ' + str(self.raison)

@receiver(post_save, sender=Whitelist)
def whitelist_post_save(sender, **kwargs):
    whitelist = kwargs['instance']
    user = whitelist.user
    user.ldap_sync(base=False, access_refresh=True, mac_refresh=False)
    is_created = kwargs['created']
    if is_created:
        regen('dhcp')
        regen('mac_ip_list')
    if user.has_access():
        regen('dhcp')
        regen('mac_ip_list')

@receiver(post_delete, sender=Whitelist)
def whitelist_post_delete(sender, **kwargs):
    user = kwargs['instance'].user
    user.ldap_sync(base=False, access_refresh=True, mac_refresh=False)
    regen('dhcp')
    regen('mac_ip_list')

class Request(models.Model):
    PASSWD = 'PW'
    EMAIL = 'EM'
    TYPE_CHOICES = (
        (PASSWD, 'Mot de passe'),
        (EMAIL, 'Email'),
    )
    type = models.CharField(max_length=2, choices=TYPE_CHOICES)
    token = models.CharField(max_length=32)
    user = models.ForeignKey('User', on_delete=models.PROTECT)
    created_at = models.DateTimeField(auto_now_add=True, editable=False)
    expires_at = models.DateTimeField()

    def save(self):
        if not self.expires_at:
            options, created = GeneralOption.objects.get_or_create()
            self.expires_at = timezone.now() \
                + datetime.timedelta(hours=options.req_expire_hrs)
        if not self.token:
            self.token = str(uuid.uuid4()).replace('-', '')  # remove hyphens
        super(Request, self).save()

class LdapUser(ldapdb.models.Model):
    """
    Class for representing an LDAP user entry.
    """
    # LDAP meta-data
    base_dn = LDAP['base_user_dn']
    object_classes = ['inetOrgPerson','top','posixAccount','sambaSamAccount','radiusprofile', 'shadowAccount']

    # attributes
    gid = ldapdb.models.fields.IntegerField(db_column='gidNumber')
    name = ldapdb.models.fields.CharField(db_column='cn', max_length=200, primary_key=True)
    uid = ldapdb.models.fields.CharField(db_column='uid', max_length=200)
    uidNumber = ldapdb.models.fields.IntegerField(db_column='uidNumber', unique=True)
    sn = ldapdb.models.fields.CharField(db_column='sn', max_length=200)
    login_shell = ldapdb.models.fields.CharField(db_column='loginShell', max_length=200, blank=True, null=True)
    mail = ldapdb.models.fields.CharField(db_column='mail', max_length=200) 
    given_name = ldapdb.models.fields.CharField(db_column='givenName', max_length=200)
    home_directory = ldapdb.models.fields.CharField(db_column='homeDirectory', max_length=200)
    display_name = ldapdb.models.fields.CharField(db_column='displayName', max_length=200, blank=True, null=True)
    dialupAccess = ldapdb.models.fields.CharField(db_column='dialupAccess')
    sambaSID = ldapdb.models.fields.IntegerField(db_column='sambaSID', unique=True)
    user_password = ldapdb.models.fields.CharField(db_column='userPassword', max_length=200, blank=True, null=True)
    sambat_nt_password = ldapdb.models.fields.CharField(db_column='sambaNTPassword', max_length=200, blank=True, null=True)
    macs = ldapdb.models.fields.ListField(db_column='radiusCallingStationId', max_length=200, blank=True, null=True)
    shadowexpire = ldapdb.models.fields.CharField(db_column='shadowExpire', blank=True, null=True)

    def __str__(self):
        return self.name

    def __unicode__(self):
        return self.name

    def save(self, *args, **kwargs):
        self.sn = self.name
        self.uid = self.name
        self.sambaSID = self.uidNumber
        super(LdapUser, self).save(*args, **kwargs)

class LdapUserGroup(ldapdb.models.Model):
    """
    Class for representing an LDAP user entry.
    """
    # LDAP meta-data
    base_dn = LDAP['base_usergroup_dn']
    object_classes = ['posixGroup']

    # attributes
    gid = ldapdb.models.fields.IntegerField(db_column='gidNumber')
    members = ldapdb.models.fields.ListField(db_column='memberUid', blank=True)
    name = ldapdb.models.fields.CharField(db_column='cn', max_length=200, primary_key=True)

    def __str__(self):
        return self.name

class LdapServiceUser(ldapdb.models.Model):
    """
    Class for representing an LDAP userservice entry.
    """
    # LDAP meta-data
    base_dn = LDAP['base_userservice_dn']
    object_classes = ['applicationProcess','simpleSecurityObject']

    # attributes
    name = ldapdb.models.fields.CharField(db_column='cn', max_length=200, primary_key=True)
    user_password = ldapdb.models.fields.CharField(db_column='userPassword', max_length=200, blank=True, null=True)

    def __str__(self):
        return self.name

class LdapServiceUserGroup(ldapdb.models.Model):
    """
    Class for representing an LDAP userservice entry.
    """
    # LDAP meta-data
    base_dn = LDAP['base_userservicegroup_dn']
    object_classes = ['groupOfNames']

    # attributes
    name = ldapdb.models.fields.CharField(db_column='cn', max_length=200, primary_key=True)
    members = ldapdb.models.fields.ListField(db_column='member', blank=True)

    def __str__(self):
        return self.name