import logging

from django.conf import settings
from django.contrib.auth.models import User
from django.db import models
from django.db.models.signals import post_save
from django.dispatch import receiver
from django.utils.translation import gettext_lazy, pgettext_lazy
from django_celery_beat.models import PeriodicTask
from rest_framework.authtoken.models import Token
from solo.models import SingletonModel

from core.fields import IntegerField

_log = logging.getLogger(__name__)


@receiver(post_save, sender=settings.AUTH_USER_MODEL)
def create_auth_token(sender, instance=None, created=False, **kwargs):
    """ Generate Auth token for user

    See https://www.django-rest-framework.org/api-guide/authentication/#generating-tokens
    """
    if created:
        Token.objects.create(user=instance)


class NameDescriptionModel(models.Model):
    """ Abstract model for name - description pair model """
    name = models.CharField(max_length=128, verbose_name=gettext_lazy(
        'Name'))
    description = models.TextField(null=True,
                                   blank=True,
                                   verbose_name=gettext_lazy('Description'),
                                   help_text=gettext_lazy('Description'))

    class Meta:
        abstract = True
        ordering = ['name']

    def __str__(self):
        return self.name


class UniqueNameDescriptionModel(NameDescriptionModel):
    """ NameDescriptionModel heir to make name field unique """
    name = models.CharField(max_length=128, verbose_name=gettext_lazy('Name'), unique=True)

    class Meta:
        abstract = True
        ordering = ['name']


class SensorConnectedMixin(models.Model):
    """ Add connection to sensor by name.

    Sensor can be ARMAIF or Endpoint
    """
    sensor = models.CharField(null=True, blank=True, max_length=128, verbose_name=gettext_lazy("Sensor name"))

    class Meta:
        abstract = True


class UpdatedNameDescriptionModel(NameDescriptionModel):
    """ Abstract model for name - description pair with updated info """
    updated = models.DateTimeField(auto_now=True, verbose_name=gettext_lazy(
        'Updated'), help_text=gettext_lazy('Date and time, when asset was updated'))

    class Meta:
        abstract = True
        ordering = ['updated', 'name']

    def __str__(self):
        return self.name


class VulnerabilityEffect(NameDescriptionModel):
    """ Possible Vulnerability effect """
    pass


class VulnerabilityRecommendations(NameDescriptionModel):
    """ Recommendations how to close Vulnerability """
    pass


class Vulnerability(UniqueNameDescriptionModel):
    """ Description of one Vulnerability """
    detection_method = models.TextField(verbose_name=gettext_lazy('Detection method'))
    affected_software = models.TextField(verbose_name=gettext_lazy('Vulnerable software'))
    close_recommendations = models.ManyToManyField(VulnerabilityRecommendations,
                                                   verbose_name=gettext_lazy('Resolve recommendations'),
                                                   help_text=gettext_lazy('How to resolve the vulnerability'),
                                                   blank=True)
    effects = models.ManyToManyField(VulnerabilityEffect,
                                     verbose_name=pgettext_lazy('as consequences', 'Effects'),
                                     help_text=gettext_lazy('Consequences of the vulnerability'),
                                     blank=True)


class ConnectionType(NameDescriptionModel):
    """ Asset connection type """
    pass


class Connection(models.Model):
    """
    Connection between two assets
    """

    from assets.models.assets import Asset

    class ProtocolType(models.TextChoices):
        TCP = 'TCP', gettext_lazy('TCP protocol')
        UDP = 'UDP', gettext_lazy('UDP protocol')

    src_asset = models.ForeignKey(Asset, related_name='src', on_delete=models.CASCADE,
                                  verbose_name=gettext_lazy('Source asset'))
    dst_asset = models.ForeignKey(Asset,
                                  related_name='dst',
                                  on_delete=models.CASCADE,
                                  verbose_name=gettext_lazy('Destination asset'))
    src_port = IntegerField(verbose_name=gettext_lazy('Source port'), null=True, blank=True,
                            min_value=0, max_value=65535)
    dst_port = IntegerField(verbose_name=gettext_lazy('Destination port'), null=True, blank=True,
                            min_value=0, max_value=65535)
    connection_protocol = models.CharField(choices=ProtocolType.choices,
                                           verbose_name=gettext_lazy('Connection protocol'),
                                           help_text=gettext_lazy('Connection protocol type'), blank=True, null=True,
                                           default=ProtocolType.TCP, max_length=10)
    created = models.DateTimeField(auto_now=True)
    updated = models.DateTimeField(auto_now=True, verbose_name=gettext_lazy(
        'Updated'), help_text=gettext_lazy('Date and time, when connection was updated'))