from rest_framework import viewsets, permissions
from rest_framework.response import Response
from django.db import transaction

from .models import MatrixServiceProduct
from .serializers import MatrixServiceProductSerializer

from uncloud_pay.helpers import ProductViewSet
from uncloud_pay.models import Order
from uncloud_vm.models import VMProduct, VMDiskProduct

def create_managed_vm(cores, ram, disk_size, image, order):
    # Create VM
    disk = VMDiskProduct(
            owner=order.owner,
            order=order,
            size_in_gb=disk_size,
            image=image)
    vm = VMProduct(
            name="Managed Service Host",
            owner=order.owner,
            cores=cores,
            ram_in_gb=ram,
            primary_disk=disk)
    disk.vm = vm

    vm.save()
    disk.save()

    return vm


class MatrixServiceProductViewSet(ProductViewSet):
    permission_classes = [permissions.IsAuthenticated]
    serializer_class = MatrixServiceProductSerializer

    def get_queryset(self):
        return MatrixServiceProduct.objects.filter(owner=self.request.user)

    @transaction.atomic
    def create(self, request):
        # Extract serializer data.
        serializer = self.get_serializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        order_recurring_period = serializer.validated_data.pop("recurring_period")

        # Create base order.)
        order = Order.objects.create(
                recurring_period=order_recurring_period,
                owner=request.user)

        # Create unerderlying VM.
        data = serializer.validated_data.pop('vm')
        vm = create_managed_vm(
                order=order,
                cores=data['cores'],
                ram=data['ram_in_gb'],
                disk_size=data['primary_disk']['size_in_gb'],
                image=MatrixServiceProduct.base_image())

        # Create service.
        service = serializer.save(
                order=order,
                owner=request.user,
                vm=vm)

        return Response(serializer.data)