from rest_framework import serializers

from dcim.api.serializers import (
    DeviceRoleSerializer, DeviceTypeSerializer, LocationSerializer, PlatformSerializer, RackRoleSerializer,
    RackSerializer, RackTypeSerializer, SiteSerializer,
)
from dcim.choices import RackWidthChoices
from dcim.models import Location, Rack, Site
from netbox.api.serializers import NetBoxModelSerializer
from tenancy.api.serializers import TenantGroupSerializer, TenantSerializer
from tenancy.models import Tenant

from ..choices import ConceptStatusChoices
from ..models import ConceptCable, ConceptComponent, ConceptDeployment, ConceptDevice, RackConcept

__all__ = (
    'ConceptCableSerializer',
    'ConceptComponentSerializer',
    'ConceptDeploySerializer',
    'ConceptDeploymentSerializer',
    'ConceptDeviceSerializer',
    'RackConceptCloneSerializer',
    'RackConceptSerializer',
    'RackCopySerializer',
)


class RackConceptSerializer(NetBoxModelSerializer):
    url = serializers.HyperlinkedIdentityField(
        view_name='plugins-api:netbox_rack_concept-api:rackconcept-detail'
    )
    tenant = TenantSerializer(nested=True, required=False, allow_null=True)
    tenant_group = TenantGroupSerializer(nested=True, required=False, allow_null=True)
    rack_type = RackTypeSerializer(nested=True, required=False, allow_null=True)
    rack_role = RackRoleSerializer(nested=True, required=False, allow_null=True)
    default_site = SiteSerializer(nested=True, required=False, allow_null=True)
    default_location = LocationSerializer(nested=True, required=False, allow_null=True)
    source_rack = RackSerializer(nested=True, required=False, allow_null=True)
    device_count = serializers.IntegerField(read_only=True)
    utilization = serializers.IntegerField(read_only=True)

    class Meta:
        model = RackConcept
        fields = (
            'id', 'url', 'display_url', 'display', 'name', 'status', 'description', 'tenant_group', 'tenant',
            'rack_type', 'form_factor', 'width', 'u_height', 'starting_unit', 'desc_units', 'outer_width',
            'outer_height', 'outer_depth', 'outer_unit', 'mounting_depth', 'airflow', 'max_weight',
            'default_site', 'default_location', 'rack_role', 'source_rack', 'comments', 'tags',
            'custom_fields', 'created', 'last_updated', 'device_count', 'utilization',
        )
        brief_fields = ('id', 'url', 'display', 'name', 'status', 'u_height', 'description')


class ConceptDeviceSerializer(NetBoxModelSerializer):
    url = serializers.HyperlinkedIdentityField(
        view_name='plugins-api:netbox_rack_concept-api:conceptdevice-detail'
    )
    concept = RackConceptSerializer(nested=True)
    device_type = DeviceTypeSerializer(nested=True, required=False, allow_null=True)
    role = DeviceRoleSerializer(nested=True, required=False, allow_null=True)
    platform = PlatformSerializer(nested=True, required=False, allow_null=True)
    tenant = TenantSerializer(nested=True, required=False, allow_null=True)
    effective_u_height = serializers.DecimalField(
        max_digits=4, decimal_places=1, read_only=True
    )

    class Meta:
        model = ConceptDevice
        fields = (
            'id', 'url', 'display_url', 'display', 'concept', 'name', 'label', 'status', 'device_type', 'role',
            'platform', 'tenant', 'position', 'face', 'width_fraction', 'horizontal_position', 'u_height',
            'is_full_depth', 'effective_u_height', 'serial', 'source_device', 'description', 'comments', 'tags',
            'custom_fields', 'created', 'last_updated',
        )
        brief_fields = ('id', 'url', 'display', 'name', 'position', 'face', 'device_type')


class ConceptDeploymentSerializer(serializers.ModelSerializer):
    rack = RackSerializer(nested=True, read_only=True, allow_null=True)

    class Meta:
        model = ConceptDeployment
        fields = ('id', 'rack', 'rack_name', 'device_count', 'user', 'created')


class ConceptComponentSerializer(NetBoxModelSerializer):
    url = serializers.HyperlinkedIdentityField(
        view_name='plugins-api:netbox_rack_concept-api:conceptcomponent-detail'
    )
    device = ConceptDeviceSerializer(nested=True)
    is_connected = serializers.BooleanField(read_only=True)

    class Meta:
        model = ConceptComponent
        fields = (
            'id', 'url', 'display_url', 'display', 'device', 'component_type', 'name', 'label', 'port_type',
            'positions', 'color', 'description', 'is_connected', 'tags', 'custom_fields', 'created', 'last_updated',
        )
        brief_fields = ('id', 'url', 'display', 'name', 'component_type', 'device')


class ConceptCableSerializer(NetBoxModelSerializer):
    url = serializers.HyperlinkedIdentityField(
        view_name='plugins-api:netbox_rack_concept-api:conceptcable-detail'
    )
    termination_a = ConceptComponentSerializer(nested=True)
    termination_b = ConceptComponentSerializer(nested=True)

    class Meta:
        model = ConceptCable
        fields = (
            'id', 'url', 'display_url', 'display', 'termination_a', 'termination_b', 'status', 'type', 'color',
            'label', 'description', 'comments', 'tags', 'custom_fields', 'created', 'last_updated',
        )
        brief_fields = ('id', 'url', 'display', 'label', 'termination_a', 'termination_b')


#
# Action payloads
#

class RackCopySerializer(serializers.Serializer):
    """POST body for copying a real rack into a new concept."""
    rack = serializers.PrimaryKeyRelatedField(queryset=Rack.objects.all())
    name = serializers.CharField(max_length=100)
    status = serializers.ChoiceField(choices=ConceptStatusChoices, default=ConceptStatusChoices.STATUS_DRAFT)
    tenant = serializers.PrimaryKeyRelatedField(queryset=Tenant.objects.all(), required=False, allow_null=True)
    description = serializers.CharField(max_length=200, required=False, allow_blank=True, default='')
    include_devices = serializers.BooleanField(default=True)
    include_device_names = serializers.BooleanField(default=True)
    override_width = serializers.ChoiceField(choices=RackWidthChoices, required=False, allow_null=True, default=None)
    override_u_height = serializers.IntegerField(min_value=1, max_value=100, required=False, allow_null=True, default=None)
    override_starting_unit = serializers.IntegerField(min_value=1, required=False, allow_null=True, default=None)


class RackConceptCloneSerializer(serializers.Serializer):
    """POST body for duplicating a concept."""
    name = serializers.CharField(max_length=100)
    status = serializers.ChoiceField(choices=ConceptStatusChoices, default=ConceptStatusChoices.STATUS_DRAFT)
    tenant = serializers.PrimaryKeyRelatedField(queryset=Tenant.objects.all(), required=False, allow_null=True)
    include_devices = serializers.BooleanField(default=True)


class MergeConceptsSerializer(serializers.Serializer):
    """POST body for stacking two concepts into one taller one."""
    concept_bottom = serializers.PrimaryKeyRelatedField(queryset=RackConcept.objects.all())
    concept_top = serializers.PrimaryKeyRelatedField(queryset=RackConcept.objects.all())
    name = serializers.CharField(max_length=100)
    status = serializers.ChoiceField(choices=ConceptStatusChoices, default=ConceptStatusChoices.STATUS_DRAFT)
    tenant = serializers.PrimaryKeyRelatedField(queryset=Tenant.objects.all(), required=False, allow_null=True)
    width = serializers.ChoiceField(choices=RackWidthChoices, required=False, allow_null=True, default=None)
    u_height = serializers.IntegerField(min_value=1, max_value=100, required=False, allow_null=True, default=None)
    starting_unit = serializers.IntegerField(min_value=1, default=1)
    description = serializers.CharField(max_length=200, required=False, allow_blank=True, default='')

    def validate(self, attrs):
        if attrs['concept_bottom'].pk == attrs['concept_top'].pk:
            raise serializers.ValidationError('concept_bottom and concept_top must be different concepts.')
        return attrs


class ConceptDeploySerializer(serializers.Serializer):
    """POST body for materialising a concept."""
    name_pattern = serializers.CharField(max_length=100)
    count = serializers.IntegerField(min_value=1, max_value=100, default=1)
    start_index = serializers.IntegerField(default=1)
    site = serializers.PrimaryKeyRelatedField(queryset=Site.objects.all())
    location = serializers.PrimaryKeyRelatedField(queryset=Location.objects.all(), required=False, allow_null=True)
    tenant = serializers.PrimaryKeyRelatedField(queryset=Tenant.objects.all(), required=False, allow_null=True)
    create_devices = serializers.BooleanField(default=True)
    device_name_pattern = serializers.CharField(max_length=100, required=False, allow_blank=True, default='')
    skip_unnamed_devices = serializers.BooleanField(default=True)
    dry_run = serializers.BooleanField(
        default=False,
        help_text='Return the planned rack names and warnings without creating anything'
    )

    def validate(self, attrs):
        try:
            names = [
                attrs['name_pattern'].format(n=i)
                for i in range(attrs['start_index'], attrs['start_index'] + attrs['count'])
            ]
        except (IndexError, KeyError, ValueError) as exc:
            raise serializers.ValidationError({'name_pattern': f'Invalid pattern: {exc}'})

        if len(set(names)) != len(names):
            raise serializers.ValidationError({
                'name_pattern': 'The pattern produces duplicate names. Include {n} when creating more than one rack.'
            })
        clashes = list(Rack.objects.filter(site=attrs['site'], name__in=names).values_list('name', flat=True))
        if clashes:
            raise serializers.ValidationError({
                'name_pattern': f'These racks already exist at the site: {", ".join(sorted(clashes))}'
            })

        attrs['rack_names'] = names
        return attrs