from django import forms
from django.contrib.contenttypes.models import ContentType
from django.core.exceptions import ValidationError
from django.utils.translation import gettext as _

from dcim.forms.common import InterfaceCommonForm
from dcim.forms.model_forms import INTERFACE_MODE_HELP_TEXT
from dcim.models import Device, DeviceRole, Platform, Rack, Region, Site, SiteGroup
from ipam.models import IPAddress, VLAN, VLANGroup, VRF
from netbox.forms import NetBoxModelForm
from tenancy.forms import TenancyForm
from utilities.forms import (
    BootstrapMixin, CommentField, ConfirmationForm, DynamicModelChoiceField, DynamicModelMultipleChoiceField,
    JSONField, SlugField, StaticSelect,
)
from virtualization.models import *

__all__ = (
    'ClusterAddDevicesForm',
    'ClusterForm',
    'ClusterGroupForm',
    'ClusterRemoveDevicesForm',
    'ClusterTypeForm',
    'VirtualMachineForm',
    'VMInterfaceForm',
)


class ClusterTypeForm(NetBoxModelForm):
    slug = SlugField()

    fieldsets = (
        ('Cluster Type', (
            'name', 'slug', 'description', 'tags',
        )),
    )

    class Meta:
        model = ClusterType
        fields = (
            'name', 'slug', 'description', 'tags',
        )


class ClusterGroupForm(NetBoxModelForm):
    slug = SlugField()

    fieldsets = (
        ('Cluster Group', (
            'name', 'slug', 'description', 'tags',
        )),
    )

    class Meta:
        model = ClusterGroup
        fields = (
            'name', 'slug', 'description', 'tags',
        )


class ClusterForm(TenancyForm, NetBoxModelForm):
    type = DynamicModelChoiceField(
        queryset=ClusterType.objects.all()
    )
    group = DynamicModelChoiceField(
        queryset=ClusterGroup.objects.all(),
        required=False
    )
    region = DynamicModelChoiceField(
        queryset=Region.objects.all(),
        required=False,
        initial_params={
            'sites': '$site'
        }
    )
    site_group = DynamicModelChoiceField(
        queryset=SiteGroup.objects.all(),
        required=False,
        initial_params={
            'sites': '$site'
        }
    )
    site = DynamicModelChoiceField(
        queryset=Site.objects.all(),
        required=False,
        query_params={
            'region_id': '$region',
            'group_id': '$site_group',
        }
    )
    comments = CommentField()

    fieldsets = (
        ('Cluster', ('name', 'type', 'group', 'status', 'description', 'tags')),
        ('Site', ('region', 'site_group', 'site')),
        ('Tenancy', ('tenant_group', 'tenant')),
    )

    class Meta:
        model = Cluster
        fields = (
            'name', 'type', 'group', 'status', 'tenant', 'region', 'site_group', 'site', 'description', 'comments',
            'tags',
        )
        widgets = {
            'status': StaticSelect(),
        }


class ClusterAddDevicesForm(BootstrapMixin, forms.Form):
    region = DynamicModelChoiceField(
        queryset=Region.objects.all(),
        required=False,
        null_option='None'
    )
    site_group = DynamicModelChoiceField(
        queryset=SiteGroup.objects.all(),
        required=False,
        null_option='None'
    )
    site = DynamicModelChoiceField(
        queryset=Site.objects.all(),
        required=False,
        query_params={
            'region_id': '$region',
            'group_id': '$site_group',
        }
    )
    rack = DynamicModelChoiceField(
        queryset=Rack.objects.all(),
        required=False,
        null_option='None',
        query_params={
            'site_id': '$site'
        }
    )
    devices = DynamicModelMultipleChoiceField(
        queryset=Device.objects.all(),
        query_params={
            'site_id': '$site',
            'rack_id': '$rack',
            'cluster_id': 'null',
        }
    )

    class Meta:
        fields = [
            'region', 'site', 'rack', 'devices',
        ]

    def __init__(self, cluster, *args, **kwargs):

        self.cluster = cluster

        super().__init__(*args, **kwargs)

        self.fields['devices'].choices = []

    def clean(self):
        super().clean()

        # If the Cluster is assigned to a Site, all Devices must be assigned to that Site.
        if self.cluster.site is not None:
            for device in self.cleaned_data.get('devices', []):
                if device.site != self.cluster.site:
                    raise ValidationError({
                        'devices': "{} belongs to a different site ({}) than the cluster ({})".format(
                            device, device.site, self.cluster.site
                        )
                    })


class ClusterRemoveDevicesForm(ConfirmationForm):
    pk = forms.ModelMultipleChoiceField(
        queryset=Device.objects.all(),
        widget=forms.MultipleHiddenInput()
    )


class VirtualMachineForm(TenancyForm, NetBoxModelForm):
    site = DynamicModelChoiceField(
        queryset=Site.objects.all(),
        required=False
    )
    cluster_group = DynamicModelChoiceField(
        queryset=ClusterGroup.objects.all(),
        required=False,
        null_option='None',
        initial_params={
            'clusters': '$cluster'
        }
    )
    cluster = DynamicModelChoiceField(
        queryset=Cluster.objects.all(),
        required=False,
        query_params={
            'site_id': '$site',
            'group_id': '$cluster_group',
        }
    )
    device = DynamicModelChoiceField(
        queryset=Device.objects.all(),
        required=False,
        query_params={
            'cluster_id': '$cluster',
            'site_id': '$site',
        },
        help_text=_("Optionally pin this VM to a specific host device within the cluster")
    )
    role = DynamicModelChoiceField(
        queryset=DeviceRole.objects.all(),
        required=False,
        query_params={
            "vm_role": "True"
        }
    )
    platform = DynamicModelChoiceField(
        queryset=Platform.objects.all(),
        required=False
    )
    local_context_data = JSONField(
        required=False,
        label=''
    )
    comments = CommentField()

    fieldsets = (
        ('Virtual Machine', ('name', 'role', 'status', 'description', 'tags')),
        ('Site/Cluster', ('site', 'cluster_group', 'cluster', 'device')),
        ('Tenancy', ('tenant_group', 'tenant')),
        ('Management', ('platform', 'primary_ip4', 'primary_ip6')),
        ('Resources', ('vcpus', 'memory', 'disk')),
        ('Config Context', ('local_context_data',)),
    )

    class Meta:
        model = VirtualMachine
        fields = [
            'name', 'status', 'site', 'cluster_group', 'cluster', 'device', 'role', 'tenant_group', 'tenant',
            'platform', 'primary_ip4', 'primary_ip6', 'vcpus', 'memory', 'disk', 'description', 'comments', 'tags',
            'local_context_data',
        ]
        help_texts = {
            'local_context_data': _("Local config context data overwrites all sources contexts in the final rendered "
                                    "config context"),
        }
        widgets = {
            "status": StaticSelect(),
            'primary_ip4': StaticSelect(),
            'primary_ip6': StaticSelect(),
        }

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        if self.instance.pk:

            # Compile list of choices for primary IPv4 and IPv6 addresses
            for family in [4, 6]:
                ip_choices = [(None, '---------')]

                # Gather PKs of all interfaces belonging to this VM
                interface_ids = self.instance.interfaces.values_list('pk', flat=True)

                # Collect interface IPs
                interface_ips = IPAddress.objects.filter(
                    address__family=family,
                    assigned_object_type=ContentType.objects.get_for_model(VMInterface),
                    assigned_object_id__in=interface_ids
                )
                if interface_ips:
                    ip_list = [(ip.id, f'{ip.address} ({ip.assigned_object})') for ip in interface_ips]
                    ip_choices.append(('Interface IPs', ip_list))
                # Collect NAT IPs
                nat_ips = IPAddress.objects.prefetch_related('nat_inside').filter(
                    address__family=family,
                    nat_inside__assigned_object_type=ContentType.objects.get_for_model(VMInterface),
                    nat_inside__assigned_object_id__in=interface_ids
                )
                if nat_ips:
                    ip_list = [(ip.id, f'{ip.address} (NAT)') for ip in nat_ips]
                    ip_choices.append(('NAT IPs', ip_list))
                self.fields['primary_ip{}'.format(family)].choices = ip_choices

        else:

            # An object that doesn't exist yet can't have any IPs assigned to it
            self.fields['primary_ip4'].choices = []
            self.fields['primary_ip4'].widget.attrs['readonly'] = True
            self.fields['primary_ip6'].choices = []
            self.fields['primary_ip6'].widget.attrs['readonly'] = True


class VMInterfaceForm(InterfaceCommonForm, NetBoxModelForm):
    virtual_machine = DynamicModelChoiceField(
        queryset=VirtualMachine.objects.all()
    )
    parent = DynamicModelChoiceField(
        queryset=VMInterface.objects.all(),
        required=False,
        label=_('Parent interface'),
        query_params={
            'virtual_machine_id': '$virtual_machine',
        }
    )
    bridge = DynamicModelChoiceField(
        queryset=VMInterface.objects.all(),
        required=False,
        label=_('Bridged interface'),
        query_params={
            'virtual_machine_id': '$virtual_machine',
        }
    )
    vlan_group = DynamicModelChoiceField(
        queryset=VLANGroup.objects.all(),
        required=False,
        label=_('VLAN group')
    )
    untagged_vlan = DynamicModelChoiceField(
        queryset=VLAN.objects.all(),
        required=False,
        label=_('Untagged VLAN'),
        query_params={
            'group_id': '$vlan_group',
            'available_on_virtualmachine': '$virtual_machine',
        }
    )
    tagged_vlans = DynamicModelMultipleChoiceField(
        queryset=VLAN.objects.all(),
        required=False,
        label=_('Tagged VLANs'),
        query_params={
            'group_id': '$vlan_group',
            'available_on_virtualmachine': '$virtual_machine',
        }
    )
    vrf = DynamicModelChoiceField(
        queryset=VRF.objects.all(),
        required=False,
        label=_('VRF')
    )

    fieldsets = (
        ('Interface', ('virtual_machine', 'name', 'description', 'tags')),
        ('Addressing', ('vrf', 'mac_address')),
        ('Operation', ('mtu', 'enabled')),
        ('Related Interfaces', ('parent', 'bridge')),
        ('802.1Q Switching', ('mode', 'vlan_group', 'untagged_vlan', 'tagged_vlans')),
    )

    class Meta:
        model = VMInterface
        fields = [
            'virtual_machine', 'name', 'parent', 'bridge', 'enabled', 'mac_address', 'mtu', 'description', 'mode',
            'vlan_group', 'untagged_vlan', 'tagged_vlans', 'vrf', 'tags',
        ]
        widgets = {
            'mode': StaticSelect()
        }
        labels = {
            'mode': '802.1Q Mode',
        }
        help_texts = {
            'mode': INTERFACE_MODE_HELP_TEXT,
        }

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        # Disable reassignment of VirtualMachine when editing an existing instance
        if self.instance.pk:
            self.fields['virtual_machine'].disabled = True