from django.contrib.auth import get_user_model

from rest_framework import serializers

from .models import VMHost, VMProduct, VMSnapshotProduct, VMDiskProduct, VMDiskImageProduct, VMCluster
from uncloud_pay.models import RecurringPeriod

GB_SSD_PER_DAY=0.012
GB_HDD_PER_DAY=0.0006

GB_SSD_PER_DAY=0.012
GB_HDD_PER_DAY=0.0006


class VMHostSerializer(serializers.HyperlinkedModelSerializer):
    vms = serializers.PrimaryKeyRelatedField(many=True, read_only=True)

    class Meta:
        model = VMHost
        fields = '__all__'
        read_only_fields = [ 'vms' ]

class VMClusterSerializer(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = VMCluster
        fields = '__all__'


class VMDiskProductSerializer(serializers.ModelSerializer):
    class Meta:
        model = VMDiskProduct
        fields = '__all__'

class CreateVMDiskProductSerializer(serializers.ModelSerializer):
    class Meta:
        model = VMDiskProduct
        fields = ['size_in_gb', 'image']

class CreateManagedVMDiskProductSerializer(serializers.ModelSerializer):
    class Meta:
        model = VMDiskProduct
        fields = ['size_in_gb']

class VMDiskImageProductSerializer(serializers.ModelSerializer):
    class Meta:
        model = VMDiskImageProduct
        fields = '__all__'

class DCLVMProductSerializer(serializers.HyperlinkedModelSerializer):
    """
    Create an interface similar to standard DCL
    """

    # Custom field used at creation (= ordering) only.
    recurring_period = serializers.ChoiceField(
        choices=VMProduct.allowed_recurring_periods())

    os_disk_uuid = serializers.UUIDField()
    # os_disk_size =

    class Meta:
        model = VMProduct

class ManagedVMProductSerializer(serializers.ModelSerializer):
    """
    Managed VM serializer used in ungleich_service app.
    """
    primary_disk = CreateManagedVMDiskProductSerializer()
    class Meta:
        model = VMProduct
        fields = [ 'cores', 'ram_in_gb', 'primary_disk']

class VMSnapshotProductSerializer(serializers.ModelSerializer):
    class Meta:
        model = VMSnapshotProduct
        fields = '__all__'


    # verify that vm.owner == user.request
    def validate_vm(self, value):
        if not value.owner == self.context['request'].user:
            raise serializers.ValidationError("VM {} not found for owner {}.".format(value,
                                                                                     self.context['request'].user))
        disks = VMDiskProduct.objects.filter(vm=value)

        if len(disks) == 0:
            raise serializers.ValidationError("VM {} does not have any disks, cannot snapshot".format(value.uuid))

        return value

    pricing = {}
    pricing['per_gb_ssd'] = 0.012
    pricing['per_gb_hdd'] = 0.0006
    pricing['recurring_period'] = 'per_day'


class VMProductSerializer(serializers.HyperlinkedModelSerializer):
    # Custom field used at creation (= ordering) only.
    recurring_period = serializers.ChoiceField(
            choices=VMProduct.allowed_recurring_periods())
    primary_disk = CreateVMDiskProductSerializer()

    class Meta:
        model = VMProduct
        fields = ['uuid', 'order', 'owner', 'status', 'name', \
                'cores', 'ram_in_gb', 'recurring_period', 'primary_disk',
                'snapshots', 'disks', 'extra_data' ]
        read_only_fields = ['uuid', 'order', 'owner', 'status']

    snapshots = VMSnapshotProductSerializer(many=True,
                                            read_only=True)

    disks = VMDiskProductSerializer(many=True,
                                    read_only=True)