from django import forms
from django.core.exceptions import ValidationError
from django.utils.translation import gettext_lazy as _

from dcim.models import Device, Interface
from ipam.models import IPAddress, RouteTarget, VLAN
from netbox.forms import NetBoxModelForm
from tenancy.forms import TenancyForm
from utilities.forms.fields import CommentField, DynamicModelChoiceField, DynamicModelMultipleChoiceField, SlugField
from utilities.forms.rendering import FieldSet, TabbedGroups
from utilities.forms.utils import add_blank_choice, get_field_value
from utilities.forms.widgets import HTMXSelect
from virtualization.models import VirtualMachine, VMInterface
from vpn.choices import *
from vpn.models import *

__all__ = (
    'IKEPolicyForm',
    'IKEProposalForm',
    'IPSecPolicyForm',
    'IPSecProfileForm',
    'IPSecProposalForm',
    'L2VPNForm',
    'L2VPNTerminationForm',
    'TunnelCreateForm',
    'TunnelForm',
    'TunnelGroupForm',
    'TunnelTerminationForm',
)


class TunnelGroupForm(NetBoxModelForm):
    slug = SlugField()

    fieldsets = (
        FieldSet('name', 'slug', 'description', 'tags', name=_('Tunnel Group')),
    )

    class Meta:
        model = TunnelGroup
        fields = [
            'name', 'slug', 'description', 'tags',
        ]


class TunnelForm(TenancyForm, NetBoxModelForm):
    group = DynamicModelChoiceField(
        queryset=TunnelGroup.objects.all(),
        label=_('Tunnel Group'),
        required=False
    )
    ipsec_profile = DynamicModelChoiceField(
        queryset=IPSecProfile.objects.all(),
        label=_('IPSec Profile'),
        required=False
    )
    comments = CommentField()

    fieldsets = (
        FieldSet('name', 'status', 'group', 'encapsulation', 'description', 'tunnel_id', 'tags', name=_('Tunnel')),
        FieldSet('ipsec_profile', name=_('Security')),
        FieldSet('tenant_group', 'tenant', name=_('Tenancy')),
    )

    class Meta:
        model = Tunnel
        fields = [
            'name', 'status', 'group', 'encapsulation', 'description', 'tunnel_id', 'ipsec_profile', 'tenant_group',
            'tenant', 'comments', 'tags',
        ]


class TunnelCreateForm(TunnelForm):
    # First termination
    termination1_role = forms.ChoiceField(
        choices=add_blank_choice(TunnelTerminationRoleChoices),
        required=False,
        label=_('Role')
    )
    termination1_type = forms.ChoiceField(
        choices=TunnelTerminationTypeChoices,
        required=False,
        widget=HTMXSelect(),
        label=_('Type')
    )
    termination1_parent = DynamicModelChoiceField(
        queryset=Device.objects.all(),
        required=False,
        selector=True,
        label=_('Device')
    )
    termination1_termination = DynamicModelChoiceField(
        queryset=Interface.objects.all(),
        required=False,
        label=_('Tunnel interface'),
        query_params={
            'device_id': '$termination1_parent',
        }
    )
    termination1_outside_ip = DynamicModelChoiceField(
        queryset=IPAddress.objects.all(),
        label=_('Outside IP'),
        required=False,
        query_params={
            'device_id': '$termination1_parent',
        }
    )

    # Second termination
    termination2_role = forms.ChoiceField(
        choices=add_blank_choice(TunnelTerminationRoleChoices),
        required=False,
        label=_('Role')
    )
    termination2_type = forms.ChoiceField(
        choices=TunnelTerminationTypeChoices,
        required=False,
        widget=HTMXSelect(),
        label=_('Type')
    )
    termination2_parent = DynamicModelChoiceField(
        queryset=Device.objects.all(),
        required=False,
        selector=True,
        label=_('Device')
    )
    termination2_termination = DynamicModelChoiceField(
        queryset=Interface.objects.all(),
        required=False,
        label=_('Tunnel interface'),
        query_params={
            'device_id': '$termination2_parent',
        }
    )
    termination2_outside_ip = DynamicModelChoiceField(
        queryset=IPAddress.objects.all(),
        required=False,
        label=_('Outside IP'),
        query_params={
            'device_id': '$termination2_parent',
        }
    )

    fieldsets = (
        FieldSet('name', 'status', 'group', 'encapsulation', 'description', 'tunnel_id', 'tags', name=_('Tunnel')),
        FieldSet('ipsec_profile', name=_('Security')),
        FieldSet('tenant_group', 'tenant', name=_('Tenancy')),
        FieldSet(
            'termination1_role', 'termination1_type', 'termination1_parent', 'termination1_termination',
            'termination1_outside_ip', name=_('First Termination')),
        FieldSet(
            'termination2_role', 'termination2_type', 'termination2_parent', 'termination2_termination',
            'termination2_outside_ip', name=_('Second Termination')),
    )

    def __init__(self, *args, initial=None, **kwargs):
        super().__init__(*args, initial=initial, **kwargs)

        if get_field_value(self, 'termination1_type') == TunnelTerminationTypeChoices.TYPE_VIRTUALMACHINE:
            self.fields['termination1_parent'].label = _('Virtual Machine')
            self.fields['termination1_parent'].queryset = VirtualMachine.objects.all()
            self.fields['termination1_termination'].queryset = VMInterface.objects.all()
            self.fields['termination1_termination'].widget.add_query_params({
                'virtual_machine_id': '$termination1_parent',
            })
            self.fields['termination1_outside_ip'].widget.add_query_params({
                'virtual_machine_id': '$termination1_parent',
            })

        if get_field_value(self, 'termination2_type') == TunnelTerminationTypeChoices.TYPE_VIRTUALMACHINE:
            self.fields['termination2_parent'].label = _('Virtual Machine')
            self.fields['termination2_parent'].queryset = VirtualMachine.objects.all()
            self.fields['termination2_termination'].queryset = VMInterface.objects.all()
            self.fields['termination2_termination'].widget.add_query_params({
                'virtual_machine_id': '$termination2_parent',
            })
            self.fields['termination2_outside_ip'].widget.add_query_params({
                'virtual_machine_id': '$termination2_parent',
            })

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

        # Validate attributes for each termination (if any)
        for term in ('termination1', 'termination2'):
            required_parameters = (
                f'{term}_role', f'{term}_parent', f'{term}_termination',
            )
            parameters = (
                *required_parameters,
                f'{term}_outside_ip',
            )
        if any([self.cleaned_data[param] for param in parameters]):
            for param in required_parameters:
                if not self.cleaned_data[param]:
                    raise forms.ValidationError({
                        param: _("This parameter is required when defining a termination.")
                    })

    def save(self, *args, **kwargs):
        instance = super().save(*args, **kwargs)

        # Create first termination
        if self.cleaned_data['termination1_termination']:
            TunnelTermination.objects.create(
                tunnel=instance,
                role=self.cleaned_data['termination1_role'],
                termination=self.cleaned_data['termination1_termination'],
                outside_ip=self.cleaned_data['termination1_outside_ip'],
            )

        # Create second termination, if defined
        if self.cleaned_data['termination2_termination']:
            TunnelTermination.objects.create(
                tunnel=instance,
                role=self.cleaned_data['termination2_role'],
                termination=self.cleaned_data['termination2_termination'],
                outside_ip=self.cleaned_data.get('termination2_outside_ip'),
            )

        return instance


class TunnelTerminationForm(NetBoxModelForm):
    tunnel = DynamicModelChoiceField(
        queryset=Tunnel.objects.all()
    )
    type = forms.ChoiceField(
        choices=TunnelTerminationTypeChoices,
        widget=HTMXSelect(),
        label=_('Type')
    )
    parent = DynamicModelChoiceField(
        queryset=Device.objects.all(),
        selector=True,
        label=_('Device')
    )
    termination = DynamicModelChoiceField(
        queryset=Interface.objects.all(),
        label=_('Tunnel interface'),
        query_params={
            'device_id': '$parent',
        }
    )
    outside_ip = DynamicModelChoiceField(
        queryset=IPAddress.objects.all(),
        label=_('Outside IP'),
        required=False,
        query_params={
            'device_id': '$parent',
        }
    )

    fieldsets = (
        FieldSet('tunnel', 'role', 'type', 'parent', 'termination', 'outside_ip', 'tags'),
    )

    class Meta:
        model = TunnelTermination
        fields = [
            'tunnel', 'role', 'termination', 'outside_ip', 'tags',
        ]

    def __init__(self, *args, initial=None, **kwargs):
        super().__init__(*args, initial=initial, **kwargs)

        if (get_field_value(self, 'type') is None and
                self.instance.pk and isinstance(self.instance.termination.parent_object, VirtualMachine)):
            self.fields['type'].initial = TunnelTerminationTypeChoices.TYPE_VIRTUALMACHINE

        # If initial or self.data is set and the type is a VIRTUALMACHINE type, swap the field querysets.
        if get_field_value(self, 'type') == TunnelTerminationTypeChoices.TYPE_VIRTUALMACHINE:
            self.fields['parent'].label = _('Virtual Machine')
            self.fields['parent'].queryset = VirtualMachine.objects.all()
            self.fields['parent'].widget.attrs['selector'] = 'virtualization.virtualmachine'
            self.fields['termination'].queryset = VMInterface.objects.all()
            self.fields['termination'].widget.add_query_params({
                'virtual_machine_id': '$parent',
            })
            self.fields['outside_ip'].widget.add_query_params({
                'virtual_machine_id': '$parent',
            })

        if self.instance.pk:
            self.fields['parent'].initial = self.instance.termination.parent_object
            self.fields['termination'].initial = self.instance.termination

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

        # Set the terminated object
        self.instance.termination = self.cleaned_data.get('termination')


class IKEProposalForm(NetBoxModelForm):

    fieldsets = (
        FieldSet('name', 'description', 'tags', name=_('Proposal')),
        FieldSet(
            'authentication_method', 'encryption_algorithm', 'authentication_algorithm', 'group', 'sa_lifetime',
            name=_('Parameters')
        ),
    )

    class Meta:
        model = IKEProposal
        fields = [
            'name', 'description', 'authentication_method', 'encryption_algorithm', 'authentication_algorithm', 'group',
            'sa_lifetime', 'comments', 'tags',
        ]


class IKEPolicyForm(NetBoxModelForm):
    proposals = DynamicModelMultipleChoiceField(
        queryset=IKEProposal.objects.all(),
        label=_('Proposals')
    )

    fieldsets = (
        FieldSet('name', 'description', 'tags', name=_('Policy')),
        FieldSet('version', 'mode', 'proposals', 'preshared_key', name=_('Parameters')),
    )

    class Meta:
        model = IKEPolicy
        fields = [
            'name', 'description', 'version', 'mode', 'proposals', 'preshared_key', 'comments', 'tags',
        ]


class IPSecProposalForm(NetBoxModelForm):

    fieldsets = (
        FieldSet('name', 'description', 'tags', name=_('Proposal')),
        FieldSet(
            'encryption_algorithm', 'authentication_algorithm', 'sa_lifetime_seconds', 'sa_lifetime_data',
            name=_('Parameters')
        ),
    )

    class Meta:
        model = IPSecProposal
        fields = [
            'name', 'description', 'encryption_algorithm', 'authentication_algorithm', 'sa_lifetime_seconds',
            'sa_lifetime_data', 'comments', 'tags',
        ]


class IPSecPolicyForm(NetBoxModelForm):
    proposals = DynamicModelMultipleChoiceField(
        queryset=IPSecProposal.objects.all(),
        label=_('Proposals')
    )

    fieldsets = (
        FieldSet('name', 'description', 'tags', name=_('Policy')),
        FieldSet('proposals', 'pfs_group', name=_('Parameters')),
    )

    class Meta:
        model = IPSecPolicy
        fields = [
            'name', 'description', 'proposals', 'pfs_group', 'comments', 'tags',
        ]


class IPSecProfileForm(NetBoxModelForm):
    ike_policy = DynamicModelChoiceField(
        queryset=IKEPolicy.objects.all(),
        label=_('IKE policy')
    )
    ipsec_policy = DynamicModelChoiceField(
        queryset=IPSecPolicy.objects.all(),
        label=_('IPSec policy')
    )
    comments = CommentField()

    fieldsets = (
        FieldSet('name', 'description', 'tags', name=_('Profile')),
        FieldSet('mode', 'ike_policy', 'ipsec_policy', name=_('Parameters')),
    )

    class Meta:
        model = IPSecProfile
        fields = [
            'name', 'description', 'mode', 'ike_policy', 'ipsec_policy', 'description', 'comments', 'tags',
        ]


#
# L2VPN
#

class L2VPNForm(TenancyForm, NetBoxModelForm):
    slug = SlugField()
    import_targets = DynamicModelMultipleChoiceField(
        label=_('Import targets'),
        queryset=RouteTarget.objects.all(),
        required=False
    )
    export_targets = DynamicModelMultipleChoiceField(
        label=_('Export targets'),
        queryset=RouteTarget.objects.all(),
        required=False
    )
    comments = CommentField()

    fieldsets = (
        FieldSet('name', 'slug', 'type', 'identifier', 'description', 'tags', name=_('L2VPN')),
        FieldSet('import_targets', 'export_targets', name=_('Route Targets')),
        FieldSet('tenant_group', 'tenant', name=_('Tenancy')),
    )

    class Meta:
        model = L2VPN
        fields = (
            'name', 'slug', 'type', 'identifier', 'import_targets', 'export_targets', 'tenant', 'description',
            'comments', 'tags'
        )


class L2VPNTerminationForm(NetBoxModelForm):
    l2vpn = DynamicModelChoiceField(
        queryset=L2VPN.objects.all(),
        required=True,
        query_params={},
        label=_('L2VPN')
    )
    vlan = DynamicModelChoiceField(
        queryset=VLAN.objects.all(),
        required=False,
        selector=True,
        label=_('VLAN')
    )
    interface = DynamicModelChoiceField(
        label=_('Interface'),
        queryset=Interface.objects.all(),
        required=False,
        selector=True
    )
    vminterface = DynamicModelChoiceField(
        queryset=VMInterface.objects.all(),
        required=False,
        selector=True,
        label=_('Interface')
    )

    fieldsets = (
        FieldSet(
            'l2vpn',
            TabbedGroups(
                FieldSet('vlan', name=_('VLAN')),
                FieldSet('interface', name=_('Device')),
                FieldSet('vminterface', name=_('Virtual Machine')),
            ),
            'tags',
        ),
    )

    class Meta:
        model = L2VPNTermination
        fields = ('l2vpn', 'tags')

    def __init__(self, *args, **kwargs):
        instance = kwargs.get('instance')
        initial = kwargs.get('initial', {}).copy()

        if instance:
            if type(instance.assigned_object) is Interface:
                initial['interface'] = instance.assigned_object
            elif type(instance.assigned_object) is VLAN:
                initial['vlan'] = instance.assigned_object
            elif type(instance.assigned_object) is VMInterface:
                initial['vminterface'] = instance.assigned_object
            kwargs['initial'] = initial

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

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

        interface = self.cleaned_data.get('interface')
        vminterface = self.cleaned_data.get('vminterface')
        vlan = self.cleaned_data.get('vlan')

        if not (interface or vminterface or vlan):
            raise ValidationError(_('A termination must specify an interface or VLAN.'))
        if len([x for x in (interface, vminterface, vlan) if x]) > 1:
            raise ValidationError(_('A termination can only have one terminating object (an interface or VLAN).'))

        self.instance.assigned_object = interface or vminterface or vlan