# -*- 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.
"""
Definition des modèles de l'application topologie.

On défini les models suivants :

- stack (id, id_min, id_max et nom) regrouppant les switches
- switch : nom, nombre de port, et interface
machine correspondante (mac, ip, etc) (voir machines.models.interface)
- Port: relié à un switch parent par foreign_key, numero du port,
relié de façon exclusive à un autre port, une machine
(serveur ou borne) ou une prise murale
- room : liste des prises murales, nom et commentaire de l'état de
la prise
"""

from __future__ import unicode_literals

import itertools

from django.db import models
from django.db.models.signals import post_save, post_delete
from django.utils.functional import cached_property
from django.dispatch import receiver
from django.core.exceptions import ValidationError
from django.db import IntegrityError
from django.db import transaction
from django.utils.translation import ugettext_lazy as _
from reversion import revisions as reversion

from machines.models import Machine, regen
from re2o.mixins import AclMixin, RevMixin


class Stack(AclMixin, RevMixin, models.Model):
    """Un objet stack. Regrouppe des switchs en foreign key
    ,contient une id de stack, un switch id min et max dans
    le stack"""
    PRETTY_NAME = "Stack de switchs"

    name = models.CharField(max_length=32, blank=True, null=True)
    stack_id = models.CharField(max_length=32, unique=True)
    details = models.CharField(max_length=255, blank=True, null=True)
    member_id_min = models.PositiveIntegerField()
    member_id_max = models.PositiveIntegerField()

    class Meta:
        permissions = (
            ("view_stack", "Peut voir un objet stack"),
        )

    def __str__(self):
        return " ".join([self.name, self.stack_id])

    def save(self, *args, **kwargs):
        self.clean()
        if not self.name:
            self.name = self.stack_id
        super(Stack, self).save(*args, **kwargs)

    def clean(self):
        """ Verification que l'id_max < id_min"""
        if self.member_id_max < self.member_id_min:
            raise ValidationError({'member_id_max': "L'id maximale est\
                inférieure à l'id minimale"})


class AccessPoint(AclMixin, Machine):
    """Define a wireless AP. Inherit from machines.interfaces

    Definition pour une borne wifi , hérite de machines.interfaces
    """
    PRETTY_NAME = "Borne WiFi"

    location = models.CharField(
        max_length=255,
        help_text="Détails sur la localisation de l'AP",
        blank=True,
        null=True
    )

    class Meta:
        permissions = (
            ("view_accesspoint", "Peut voir une borne"),
        )

    def port(self):
        """Return the queryset of ports for this device"""
        return Port.objects.filter(
            machine_interface__machine=self
        )

    def switch(self):
        """Return the switch where this is plugged"""
        return Switch.objects.filter(
            ports__machine_interface__machine=self
        )

    def building(self):
        """
        Return the building of the AP/Server (building of the switchs
        connected to...)
        """
        return Building.objects.filter(
            switchbay__switch=self.switch()
        )

    @cached_property
    def short_name(self):
        return str(self.interface_set.first().domain.name)

    @classmethod
    def all_ap_in(cls, building_instance):
        """Get a building as argument, returns all ap of a building"""
        return cls.objects.filter(
            interface__port__switch__switchbay__building=building_instance
        )

    def __str__(self):
        return str(self.interface_set.first())


class Server(Machine):
    """
    Dummy class, to retrieve servers of a building, or get switch of a server
    """

    class Meta:
        proxy = True

    def port(self):
        """Return the queryset of ports for this device"""
        return Port.objects.filter(
            machine_interface__machine=self
        )

    def switch(self):
        """Return the switch where this is plugged"""
        return Switch.objects.filter(
            ports__machine_interface__machine=self
        )

    def building(self):
        """
        Return the building of the AP/Server
        (building of the switchs connected to...)
        """
        return Building.objects.filter(
            switchbay__switch=self.switch()
        )

    @cached_property
    def short_name(self):
        return str(self.interface_set.first().domain.name)

    @classmethod
    def all_server_in(cls, building_instance):
        """Get a building as argument, returns all server of a building"""
        return cls.objects.filter(
            interface__port__switch__switchbay__building=building_instance
        ).exclude(accesspoint__isnull=False)

    def __str__(self):
        return str(self.interface_set.first())


class Switch(AclMixin, Machine):
    """ Definition d'un switch. Contient un nombre de ports (number),
    un emplacement (location), un stack parent (optionnel, stack)
    et un id de membre dans le stack (stack_member_id)
    relié en onetoone à une interface
    Pourquoi ne pas avoir fait hériter switch de interface ?
    Principalement par méconnaissance de la puissance de cette façon de faire.
    Ceci étant entendu, django crée en interne un onetoone, ce qui a un
    effet identique avec ce que l'on fait ici

    Validation au save que l'id du stack est bien dans le range id_min
    id_max de la stack parente"""
    PRETTY_NAME = "Switch / Commutateur"

    number = models.PositiveIntegerField(
        help_text="Nombre de ports"
    )
    stack = models.ForeignKey(
        'topologie.Stack',
        blank=True,
        null=True,
        on_delete=models.SET_NULL
    )
    stack_member_id = models.PositiveIntegerField(
        blank=True,
        null=True,
        help_text="Baie de brassage du switch"
    )
    model = models.ForeignKey(
        'topologie.ModelSwitch',
        blank=True,
        null=True,
        on_delete=models.SET_NULL,
        help_text="Modèle du switch"
    )
    switchbay = models.ForeignKey(
        'topologie.SwitchBay',
        blank=True,
        null=True,
        on_delete=models.SET_NULL,
        help_text="Baie de brassage du switch"
    )

    class Meta:
        unique_together = ('stack', 'stack_member_id')
        permissions = (
            ("view_switch", "Peut voir un objet switch"),
        )

    def clean(self):
        """ Verifie que l'id stack est dans le bon range
        Appelle également le clean de la classe parente"""
        super(Switch, self).clean()
        if self.stack is not None:
            if self.stack_member_id is not None:
                if (self.stack_member_id > self.stack.member_id_max) or\
                        (self.stack_member_id < self.stack.member_id_min):
                    raise ValidationError(
                        {'stack_member_id': "L'id de ce switch est en\
                            dehors des bornes permises pas la stack"}
                    )
            else:
                raise ValidationError({'stack_member_id': "L'id dans la stack\
                    ne peut être nul"})

    def create_ports(self, begin, end):
        """ Crée les ports de begin à end si les valeurs données
        sont cohérentes. """

        s_begin = s_end = 0
        nb_ports = self.ports.count()
        if nb_ports > 0:
            ports = self.ports.order_by('port').values('port')
            s_begin = ports.first().get('port')
            s_end = ports.last().get('port')

        if end < begin:
            raise ValidationError("Port de fin inférieur au port de début !")
        if end - begin > self.number:
            raise ValidationError("Ce switch ne peut avoir autant de ports.")
        begin_range = range(begin, s_begin)
        end_range = range(s_end+1, end+1)
        for i in itertools.chain(begin_range, end_range):
            port = Port()
            port.switch = self
            port.port = i
            try:
                with transaction.atomic(), reversion.create_revision():
                    port.save()
                    reversion.set_comment("Création")
            except IntegrityError:
                ValidationError("Création d'un port existant.")

    def main_interface(self):
        """ Returns the 'main' interface of the switch """
        return self.interface_set.first()

    @cached_property
    def get_name(self):
        return self.name or self.main_interface().domain.name

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


class ModelSwitch(AclMixin, RevMixin, models.Model):
    """Un modèle (au sens constructeur) de switch"""
    PRETTY_NAME = "Modèle de switch"
    reference = models.CharField(max_length=255)
    constructor = models.ForeignKey(
        'topologie.ConstructorSwitch',
        on_delete=models.PROTECT
    )

    class Meta:
        permissions = (
            ("view_modelswitch", "Peut voir un objet modelswitch"),
        )

    def __str__(self):
        return str(self.constructor) + ' ' + self.reference


class ConstructorSwitch(AclMixin, RevMixin, models.Model):
    """Un constructeur de switch"""
    PRETTY_NAME = "Constructeur de switch"
    name = models.CharField(max_length=255)

    class Meta:
        permissions = (
            ("view_constructorswitch", "Peut voir un objet constructorswitch"),
        )

    def __str__(self):
        return self.name


class SwitchBay(AclMixin, RevMixin, models.Model):
    """Une baie de brassage"""
    PRETTY_NAME = "Baie de brassage"
    name = models.CharField(max_length=255)
    building = models.ForeignKey(
        'Building',
        on_delete=models.PROTECT
    )
    info = models.CharField(
        max_length=255,
        blank=True,
        null=True,
        help_text="Informations particulières"
    )

    class Meta:
        permissions = (
            ("view_switchbay", "Peut voir un objet baie de brassage"),
        )

    def __str__(self):
        return self.name


class Building(AclMixin, RevMixin, models.Model):
    """Un batiment"""
    PRETTY_NAME = "Batiment"
    name = models.CharField(max_length=255)

    class Meta:
        permissions = (
            ("view_building", "Peut voir un objet batiment"),
        )

    def __str__(self):
        return self.name


class Port(AclMixin, RevMixin, models.Model):
    """ Definition d'un port. Relié à un switch(foreign_key),
    un port peut etre relié de manière exclusive à :
    - une chambre (room)
    - une machine (serveur etc) (machine_interface)
    - un autre port (uplink) (related)
    Champs supplémentaires :
    - RADIUS (mode STRICT : connexion sur port uniquement si machine
    d'un adhérent à jour de cotisation et que la chambre est également à
    jour de cotisation
    mode COMMON : vérification uniquement du statut de la machine
    mode NO : accepte toute demande venant du port et place sur le vlan normal
    mode BLOQ : rejet de toute authentification
    - vlan_force : override la politique générale de placement vlan, permet
    de forcer un port sur un vlan particulier. S'additionne à la politique
    RADIUS"""
    PRETTY_NAME = "Port de switch"

    switch = models.ForeignKey(
        'Switch',
        related_name="ports",
        on_delete=models.CASCADE
    )
    port = models.PositiveIntegerField()
    room = models.ForeignKey(
        'Room',
        on_delete=models.PROTECT,
        blank=True,
        null=True
    )
    machine_interface = models.ForeignKey(
        'machines.Interface',
        on_delete=models.SET_NULL,
        blank=True,
        null=True
    )
    related = models.OneToOneField(
        'self',
        null=True,
        blank=True,
        related_name='related_port'
    )
    custom_profile = models.ForeignKey(
        'PortProfile',
        on_delete=models.PROTECT,
        blank=True,
        null=True
    )
    state = models.BooleanField(
        default=True,
        help_text='Port state Active',
        verbose_name=_("Port State Active")
    )
    details = models.CharField(max_length=255, blank=True)

    class Meta:
        unique_together = ('switch', 'port')
        permissions = (
            ("view_port", "Peut voir un objet port"),
        )

    @cached_property
    def get_port_profile(self):
        """Return the config profile for this port
        :returns: the profile of self (port)"""
        def profile_or_nothing(profile):
            port_profile = PortProfile.objects.filter(
                profile_default=profile).first()
            if port_profile:
                return port_profile
            else:
                nothing_profile, _created = PortProfile.objects.get_or_create(
                    profile_default='nothing',
                    name='nothing',
                    radius_type='NO'
                )
                return nothing_profile

        if self.custom_profile:
            return self.custom_profile
        elif self.related:
            return profile_or_nothing('uplink')
        elif self.machine_interface:
            if hasattr(self.machine_interface.machine, 'accesspoint'):
                return profile_or_nothing('access_point')
            else:
                return profile_or_nothing('asso_machine')
        elif self.room:
            return profile_or_nothing('room')
        else:
            return profile_or_nothing('nothing')

    @classmethod
    def get_instance(cls, portid, *_args, **kwargs):
        return (cls.objects
                .select_related('machine_interface__domain__extension')
                .select_related('machine_interface__machine__switch')
                .select_related('room')
                .select_related('related')
                .prefetch_related('switch__interface_set__domain__extension')
                .get(pk=portid))

    def make_port_related(self):
        """ Synchronise le port distant sur self"""
        related_port = self.related
        related_port.related = self
        related_port.save()

    def clean_port_related(self):
        """ Supprime la relation related sur self"""
        related_port = self.related_port
        related_port.related = None
        related_port.save()

    def clean(self):
        """ Verifie que un seul de chambre, interface_parent et related_port
        est rempli. Verifie que le related n'est pas le port lui-même....
        Verifie que le related n'est pas déjà occupé par une machine ou une
        chambre. Si ce n'est pas le cas, applique la relation related
        Si un port related point vers self, on nettoie la relation
        A priori pas d'autre solution que de faire ça à la main. A priori
        tout cela est dans un bloc transaction, donc pas de problème de
        cohérence"""
        if hasattr(self, 'switch'):
            if self.port > self.switch.number:
                raise ValidationError(
                    "Ce port ne peut exister, numero trop élevé"
                )
        if (self.room and self.machine_interface or
                self.room and self.related or
                self.machine_interface and self.related):
            raise ValidationError(
                "Chambre, interface et related_port sont mutuellement "
                "exclusifs"
            )
        if self.related == self:
            raise ValidationError("On ne peut relier un port à lui même")
        if self.related and not self.related.related:
            if self.related.machine_interface or self.related.room:
                raise ValidationError(
                    "Le port relié est déjà occupé, veuillez le libérer "
                    "avant de créer une relation"
                )
            else:
                self.make_port_related()
        elif hasattr(self, 'related_port'):
            self.clean_port_related()

    def __str__(self):
        return str(self.switch) + " - " + str(self.port)


class Room(AclMixin, RevMixin, models.Model):
    """Une chambre/local contenant une prise murale"""
    PRETTY_NAME = "Chambre/ Prise murale"

    name = models.CharField(max_length=255, unique=True)
    details = models.CharField(max_length=255, blank=True)

    class Meta:
        ordering = ['name']
        permissions = (
            ("view_room", "Peut voir un objet chambre"),
        )

    def __str__(self):
        return self.name


class PortProfile(AclMixin, RevMixin, models.Model):
    """Contains the information of the ports' configuration for a switch"""
    TYPES = (
        ('NO', 'NO'),
        ('802.1X', '802.1X'),
        ('MAC-radius', 'MAC-radius'),
    )
    MODES = (
        ('STRICT', 'STRICT'),
        ('COMMON', 'COMMON'),
    )
    SPEED = (
        ('10-half', '10-half'),
        ('100-half', '100-half'),
        ('10-full', '10-full'),
        ('100-full', '100-full'),
        ('1000-full', '1000-full'),
        ('auto', 'auto'),
        ('auto-10', 'auto-10'),
        ('auto-100', 'auto-100'),
    )
    PROFIL_DEFAULT = (
        ('room', 'room'),
        ('accespoint', 'accesspoint'),
        ('uplink', 'uplink'),
        ('asso_machine', 'asso_machine'),
        ('nothing', 'nothing'),
    )
    name = models.CharField(max_length=255, verbose_name=_("Name"))
    profil_default = models.CharField(
        max_length=32,
        choices=PROFIL_DEFAULT,
        blank=True,
        null=True,
        unique=True,
        verbose_name=_("profil default")
    )
    vlan_untagged = models.ForeignKey(
        'machines.Vlan',
        related_name='vlan_untagged',
        on_delete=models.SET_NULL,
        blank=True,
        null=True,
        verbose_name=_("VLAN untagged")
    )
    vlan_tagged = models.ManyToManyField(
        'machines.Vlan',
        related_name='vlan_tagged',
        blank=True,
        verbose_name=_("VLAN(s) tagged")
    )
    radius_type = models.CharField(
        max_length=32,
        choices=TYPES,
        help_text="Type of radius auth : inactive, mac-address or 802.1X",
        verbose_name=_("RADIUS type")
    )
    radius_mode = models.CharField(
        max_length=32,
        choices=MODES,
        default='COMMON',
        help_text="In case of mac-auth : mode common or strict on this port",
        verbose_name=_("RADIUS mode")
    )
    speed = models.CharField(
        max_length=32,
        choices=SPEED,
        default='auto',
        help_text='Port speed limit',
        verbose_name=_("Speed")
    )
    mac_limit = models.IntegerField(
        null=True,
        blank=True,
        help_text='Limit of mac-address on this port',
        verbose_name=_("Mac limit")
    )
    flow_control = models.BooleanField(
        default=False,
        help_text='Flow control',
        verbose_name=_("Flow control")
    )
    dhcp_snooping = models.BooleanField(
        default=False,
        help_text='Protect against rogue dhcp',
        verbose_name=_("Dhcp snooping")
    )
    dhcpv6_snooping = models.BooleanField(
        default=False,
        help_text='Protect against rogue dhcpv6',
        verbose_name=_("Dhcpv6 snooping")
    )
    arp_protect = models.BooleanField(
        default=False,
        help_text='Check if ip is dhcp assigned',
        verbose_name=_("Arp protect")
    )
    ra_guard = models.BooleanField(
        default=False,
        help_text='Protect against rogue ra',
        verbose_name=_("Ra guard")
    )
    loop_protect = models.BooleanField(
        default=False,
        help_text='Protect again loop',
        verbose_name=_("Loop Protect")
    )

    class Meta:
        permissions = (
            ("view_port_profile", _("Can view a port profile object")),
        )
        verbose_name = _("Port profile")
        verbose_name_plural = _("Port profiles")

    security_parameters_fields = [
        'loop_protect',
        'ra_guard',
        'arp_protect',
        'dhcpv6_snooping',
        'dhcp_snooping',
        'flow_control'
    ]

    @cached_property
    def security_parameters_enabled(self):
        return [
            parameter
            for parameter in self.security_parameters_fields
            if getattr(self, parameter)
        ]

    @cached_property
    def security_parameters_as_str(self):
        return ','.join(self.security_parameters_enabled)

    def __str__(self):
        return self.name


@receiver(post_save, sender=AccessPoint)
def ap_post_save(**_kwargs):
    """Regeneration des noms des bornes vers le controleur"""
    regen('unifi-ap-names')
    regen("graph_topo")


@receiver(post_delete, sender=AccessPoint)
def ap_post_delete(**_kwargs):
    """Regeneration des noms des bornes vers le controleur"""
    regen('unifi-ap-names')
    regen("graph_topo")


@receiver(post_delete, sender=Stack)
def stack_post_delete(**_kwargs):
    """Vide les id des switches membres d'une stack supprimée"""
    Switch.objects.filter(stack=None).update(stack_member_id=None)


@receiver(post_save, sender=Port)
def port_post_save(**_kwargs):
    regen("graph_topo")


@receiver(post_delete, sender=Port)
def port_post_delete(**_kwargs):
    regen("graph_topo")


@receiver(post_save, sender=ModelSwitch)
def modelswitch_post_save(**_kwargs):
    regen("graph_topo")


@receiver(post_delete, sender=ModelSwitch)
def modelswitch_post_delete(**_kwargs):
    regen("graph_topo")


@receiver(post_save, sender=Building)
def building_post_save(**_kwargs):
    regen("graph_topo")


@receiver(post_delete, sender=Building)
def building_post_delete(**_kwargs):
    regen("graph_topo")


@receiver(post_save, sender=Switch)
def switch_post_save(**_kwargs):
    regen("graph_topo")


@receiver(post_delete, sender=Switch)
def switch_post_delete(**_kwargs):
    regen("graph_topo")
