# -*- coding: utf8 -*-

from django.contrib.auth.models import User
from django.db import models
from django.forms import fields, ValidationError
from django.utils.translation import ugettext_lazy as _
from firewall.fields import *
from south.modelsinspector import add_introspection_rules
from django.core.validators import MinValueValidator, MaxValueValidator
import django.conf
from django.db.models.signals import post_save
import re
import random

settings = django.conf.settings.FIREWALL_SETTINGS
class Rule(models.Model):
    """
    Common firewall rule

    Rule can be applied to: Host, Firewall, Vlan

    """
    CHOICES_type = (('host', 'host'), ('firewall', 'firewall'),
            ('vlan', 'vlan'))
    CHOICES_proto = (('tcp', 'tcp'), ('udp', 'udp'), ('icmp', 'icmp'))
    CHOICES_dir = (('0', 'out'), ('1', 'in'))

    direction = models.CharField(max_length=1, choices=CHOICES_dir,
            blank=False)
    description = models.TextField(blank=True)
    foreign_network = models.ForeignKey('VlanGroup',
            related_name="ForeignRules")
    dport = models.IntegerField(blank=True, null=True,
            validators=[MinValueValidator(1), MaxValueValidator(65535)])
    sport = models.IntegerField(blank=True, null=True,
            validators=[MinValueValidator(1), MaxValueValidator(65535)])
    proto = models.CharField(max_length=10, choices=CHOICES_proto,
            blank=True, null=True)
    extra = models.TextField(blank=True)
    accept = models.BooleanField(default=False)
    owner = models.ForeignKey(User, blank=True, null=True)
    r_type = models.CharField(max_length=10, choices=CHOICES_type)
    nat = models.BooleanField(default=False)
    nat_dport = models.IntegerField(blank=True, null=True,
            validators=[MinValueValidator(1), MaxValueValidator(65535)])
    created_at = models.DateTimeField(auto_now_add=True)
    modified_at = models.DateTimeField(auto_now=True)

    vlan = models.ForeignKey('Vlan', related_name="rules", blank=True,
            null=True)
    vlangroup = models.ForeignKey('VlanGroup', related_name="rules",
            blank=True, null=True)
    host = models.ForeignKey('Host', related_name="rules", blank=True,
            null=True)
    hostgroup = models.ForeignKey('Group', related_name="rules",
            blank=True, null=True)
    firewall = models.ForeignKey('Firewall', related_name="rules",
            blank=True, null=True)

    def __unicode__(self):
        return self.desc()

    def clean(self):
        fields = [self.vlan, self.vlangroup, self.host, self.hostgroup,
                self.firewall]
        selected_fields = [field for field in fields if field]
        if len(selected_fields) > 1:
            raise ValidationError(_('Only one field can be selected.'))

    def desc(self):
        return u'[%(type)s] %(src)s ▸ %(dst)s %(para)s %(desc)s' % {
            'type': self.r_type,
            'src': (unicode(self.foreign_network) if self.direction == '1'
                else self.r_type),
            'dst': (self.r_type if self.direction == '1'
                else unicode(self.foreign_network)),
            'para': ((("proto=%s " % self.proto) if self.proto else '') +
                     (("sport=%s " % self.sport) if self.sport else '') +
                     (("dport=%s " % self.dport) if self.dport else '')),
            'desc': self.description}

class Vlan(models.Model):
    vid = models.IntegerField(unique=True)
    name = models.CharField(max_length=20, unique=True,
            validators=[val_alfanum])
    prefix4 = models.IntegerField(default=16)
    prefix6 = models.IntegerField(default=80)
    interface = models.CharField(max_length=20, unique=True)
    net4 = models.GenericIPAddressField(protocol='ipv4', unique=True)
    net6 = models.GenericIPAddressField(protocol='ipv6', unique=True)
    ipv4 = models.GenericIPAddressField(protocol='ipv4', unique=True)
    ipv6 = models.GenericIPAddressField(protocol='ipv6', unique=True)
    snat_ip = models.GenericIPAddressField(protocol='ipv4', blank=True,
            null=True)
    snat_to = models.ManyToManyField('self', symmetrical=False, blank=True,
            null=True)
    description = models.TextField(blank=True)
    comment = models.TextField(blank=True)
    domain = models.ForeignKey('Domain')
    reverse_domain = models.TextField(validators=[val_reverse_domain])
    dhcp_pool = models.TextField(blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    owner = models.ForeignKey(User, blank=True, null=True)
    modified_at = models.DateTimeField(auto_now=True)

    def __unicode__(self):
        return self.name

    def net_ipv6(self):
        return self.net6 + "/" + unicode(self.prefix6)

    def net_ipv4(self):
        return self.net4 + "/" + unicode(self.prefix4)

class VlanGroup(models.Model):
    name = models.CharField(max_length=20, unique=True)
    vlans = models.ManyToManyField('Vlan', symmetrical=False, blank=True,
            null=True)
    description = models.TextField(blank=True)
    owner = models.ForeignKey(User, blank=True, null=True)
    created_at = models.DateTimeField(auto_now_add=True)
    modified_at = models.DateTimeField(auto_now=True)

    def __unicode__(self):
        return self.name

class Group(models.Model):
    name = models.CharField(max_length=20, unique=True)
    description = models.TextField(blank=True)
    owner = models.ForeignKey(User, blank=True, null=True)
    created_at = models.DateTimeField(auto_now_add=True)
    modified_at = models.DateTimeField(auto_now=True)

    def __unicode__(self):
        return self.name

class Host(models.Model):
    hostname = models.CharField(max_length=40, unique=True,
            validators=[val_alfanum])
    reverse = models.CharField(max_length=40, validators=[val_domain],
            blank=True, null=True)
    mac = MACAddressField(unique=True)
    ipv4 = models.GenericIPAddressField(protocol='ipv4', unique=True)
    pub_ipv4 = models.GenericIPAddressField(protocol='ipv4', blank=True,
            null=True)
    ipv6 = models.GenericIPAddressField(protocol='ipv6', unique=True,
            blank=True, null=True)
    shared_ip = models.BooleanField(default=False)
    description = models.TextField(blank=True)
    comment = models.TextField(blank=True)
    location = models.TextField(blank=True)
    vlan = models.ForeignKey('Vlan')
    owner = models.ForeignKey(User)
    groups = models.ManyToManyField('Group', symmetrical=False, blank=True,
            null=True)
    created_at = models.DateTimeField(auto_now_add=True)
    modified_at = models.DateTimeField(auto_now=True)

    def __unicode__(self):
        return self.hostname

    def save(self, *args, **kwargs):
        id = self.id
        if not self.id and self.ipv6 == "auto":
            self.ipv6 = ipv4_2_ipv6(self.ipv4)
        if (not self.shared_ip and self.pub_ipv4 and Host.objects.
                exclude(id=self.id).filter(pub_ipv4=self.pub_ipv4)):
            raise ValidationError(_("If shared_ip has been checked, "
                "pub_ipv4 has to be unique."))
        if Host.objects.exclude(id=self.id).filter(pub_ipv4=self.ipv4):
            raise ValidationError(_("You can't use another host's NAT'd "
                "address as your own IPv4."))
        self.full_clean()
        super(Host, self).save(*args, **kwargs)
        if not id:
            Record(domain=self.vlan.domain, host=self, type='A',
                    owner=self.owner).save()
            if self.ipv6:
                Record(domain=self.vlan.domain, host=self, type='AAAA',
                        owner=self.owner).save()

    def enable_net(self):
        self.groups.add(Group.objects.get(name="netezhet"))

    def add_port(self, proto, public=None, private=None):
        proto = "tcp" if proto == "tcp" else "udp"
        if self.shared_ip:
            used_ports = Rule.objects.filter(host__pub_ipv4=self.pub_ipv4,
                    nat=True, proto=proto).values_list('dport', flat=True)

            if public is None:
                public = random.randint(1024, 21000)
                if public in used_ports:
                    for i in range(1024, 21000) + range(24000, 65535):
                        if i not in used_ports:
                            public = i
                            break
                    else:
                        raise ValidationError(_("Port %s %s is already in use.") %
                                (proto, public))

            else:
                if public < 1024:
                    raise ValidationError(_("Only ports above 1024 can be used."))
                if public in used_ports:
                    raise ValidationError(_("Port %s %s is already in use.") %
                            (proto, public))

            rule = Rule(direction='1', owner=self.owner, dport=public,
                    proto=proto, nat=True, accept=True, r_type="host",
                    nat_dport=private, host=self, foreign_network=VlanGroup.
                        objects.get(name=settings["default_vlangroup"]))
        else:
            if self.rules.filter(proto=proto, dport=public):
                raise ValidationError(_("Port %s %s is already in use.") %
                    (proto, public))
            rule = Rule(direction='1', owner=self.owner, dport=public,
                    proto=proto, nat=False, accept=True, r_type="host",
                    host=self, foreign_network=VlanGroup.objects
                        .get(name=settings["default_vlangroup"]))

        rule.full_clean()
        rule.save()

    def del_port(self, proto, private):
        if self.shared_ip:
            self.rules.filter(owner=self.owner, proto=proto, host=self,
                nat_dport=private).delete()
        else:
            self.rules.filter(owner=self.owner, proto=proto, host=self,
                dport=private).delete()

    def get_hostname(self, proto):
        try:
            if proto == 'ipv6':
                res = self.record_set.filter(type='AAAA')
            elif proto == 'ipv4':
                if self.shared_ip:
                    res = Record.objects.filter(type='A',
                            address=self.pub_ipv4)
                else:
                    res = self.record_set.filter(type='A')
            return unicode(res[0].get_data()['name'])
        except:
#            raise
            if self.shared_ip:
                return self.pub_ipv4
            else:
                return self.ipv4

    def list_ports(self):
        retval = []
        for rule in self.rules.filter(owner=self.owner):
            private = rule.nat_dport if self.shared_ip else rule.dport
            forward = {
                'proto': rule.proto,
                'private': private,
            }
            if self.shared_ip:
                public4 = rule.dport
                public6 = rule.nat_dport
            else:
                public4 = public6 = rule.dport

            if True:      # ipv4
                forward['ipv4'] = {
                    'host': self.get_hostname(proto='ipv4'),
                    'port': public4,
                }
            if self.ipv6: # ipv6
                forward['ipv6'] = {
                    'host': self.get_hostname(proto='ipv6'),
                    'port': public6,
                }
            retval.append(forward)
        return retval

    def get_fqdn(self):
        return self.hostname + u'.' + unicode(self.vlan.domain)


class Firewall(models.Model):
    name = models.CharField(max_length=20, unique=True)

    def __unicode__(self):
        return self.name

class Domain(models.Model):
    name = models.CharField(max_length=40, validators=[val_domain])
    owner = models.ForeignKey(User)
    created_at = models.DateTimeField(auto_now_add=True)
    modified_at = models.DateTimeField(auto_now=True)
    ttl = models.IntegerField(default=600)
    description = models.TextField(blank=True)

    def __unicode__(self):
        return self.name

class Record(models.Model):
    CHOICES_type = (('A', 'A'), ('CNAME', 'CNAME'), ('AAAA', 'AAAA'),
            ('MX', 'MX'), ('NS', 'NS'), ('PTR', 'PTR'), ('TXT', 'TXT'))
    name = models.CharField(max_length=40, validators=[val_domain],
            blank=True, null=True)
    domain = models.ForeignKey('Domain')
    host = models.ForeignKey('Host', blank=True, null=True)
    type = models.CharField(max_length=6, choices=CHOICES_type)
    address = models.CharField(max_length=40, blank=True, null=True)
    ttl = models.IntegerField(default=600)
    owner = models.ForeignKey(User)
    description = models.TextField(blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    modified_at = models.DateTimeField(auto_now=True)

    def __unicode__(self):
        return self.desc()

    def desc(self):
        a = self.get_data()
        return (u' '.join([a['name'], a['type'], a['address']])
                if a else _('(empty)'))

    def save(self, *args, **kwargs):
        self.full_clean()
        super(Record, self).save(*args, **kwargs)

    def clean(self):
        if self.name:
            self.name = self.name.rstrip(".")    # remove trailing dots

        if self.host:
            if self.type in ['A', 'AAAA']:
                if self.address:
                    raise ValidationError(_("Can't specify address for "
                        "A or AAAA records if host is set!"))
                if self.name:
                    raise ValidationError(_("Can't specify name for "
                        "A or AAAA records if host is set!"))
            elif self.type == 'CNAME':
                if not self.name:
                    raise ValidationError(_("Name must be specified for "
                        "CNAME records if host is set!"))
                if self.address:
                    raise ValidationError(_("Can't specify address for "
                        "CNAME records if host is set!"))
        else:    # if self.host is None
            if not self.address:
                raise ValidationError(_("Address must be specified!"))

            if self.type == 'A':
                val_ipv4(self.address)
            elif self.type == 'AAAA':
                val_ipv6(self.address)
            elif self.type in ['CNAME', 'NS', 'PTR', 'TXT']:
                val_domain(self.address)
            elif self.type == 'MX':
                mx = self.address.split(':', 1)
                if not (len(mx) == 2 and mx[0].isdigit() and
                        domain_re.match(mx[1])):
                    raise ValidationError(_("Bad address format. "
                        "Should be: <priority>:<hostname>"))
            else:
                raise ValidationError(_("Unknown record type."))

    def __get_name(self):
        if self.host and self.type != 'MX':
            if self.type in ['A', 'AAAA']:
                return self.host.get_fqdn()
            elif self.type == 'CNAME':
                return self.name + '.' + unicode(self.domain)
            else:
                return self.name
        else:    # if self.host is None
            if self.name:
                return self.name + '.' + unicode(self.domain)
            else:
                return unicode(self.domain)

    def __get_address(self):
        if self.host:
            if self.type == 'A':
                return (self.host.pub_ipv4
                        if self.host.pub_ipv4 and not self.host.shared_ip
                        else self.host.ipv4)
            elif self.type == 'AAAA':
                return self.host.ipv6
            elif self.type == 'CNAME':
                return self.host.get_fqdn()
        # otherwise:
        return self.address

    def get_data(self):
        name = self.__get_name()
        address = self.__get_address()
        if self.host and self.type == 'AAAA' and not self.host.ipv6:
            return None
        elif not address or not name:
            return None
        else:
            return {'name': name,
                    'type': self.type,
                    'ttl': self.ttl,
                    'address': address}

class Blacklist(models.Model):
    CHOICES_type = (('permban', 'permanent ban'), ('tempban', 'temporary ban'), ('whitelist', 'whitelist'), ('tempwhite', 'tempwhite'))
    ipv4 = models.GenericIPAddressField(protocol='ipv4', unique=True)
    host = models.ForeignKey('Host', blank=True, null=True)
    reason = models.TextField(blank=True)
    snort_message = models.TextField(blank=True)
    type = models.CharField(max_length=10, choices=CHOICES_type, default='tempban')
    created_at = models.DateTimeField(auto_now_add=True)
    modified_at = models.DateTimeField(auto_now=True)

    def save(self, *args, **kwargs):
        self.full_clean()
        super(Blacklist, self).save(*args, **kwargs)
    def __unicode__(self):
        return self.ipv4

def send_task(sender, instance, created, **kwargs):
    from firewall.tasks import ReloadTask
    ReloadTask.apply_async(args=[sender.__name__])


post_save.connect(send_task, sender=Host)
post_save.connect(send_task, sender=Rule)
post_save.connect(send_task, sender=Domain)
post_save.connect(send_task, sender=Record)
post_save.connect(send_task, sender=Vlan)
post_save.connect(send_task, sender=Firewall)
post_save.connect(send_task, sender=Group)
post_save.connect(send_task, sender=Host)
post_save.connect(send_task, sender=Blacklist)
