import time
from uuid import uuid4
from yaml import load

from onapsdk.aai.business import Customer, ServiceInstance, ServiceSubscription
from onapsdk.configuration import settings
from onapsdk.sdc.service import Service
from onapsdk.vid import LineOfBusiness, Platform

from ..base import YamlTemplateBaseStep
from .service_ala_carte import YamlTemplateServiceAlaCarteInstantiateStep


class YamlTemplateVnfAlaCarteInstantiateStep(YamlTemplateBaseStep):
    """Instantiate vnf a'la carte using YAML template."""

    def __init__(self, cleanup=False):
        """Initialize step.

        Substeps:
            - YamlTemplateServiceAlaCarteInstantiateStep.
        """
        super().__init__(cleanup=cleanup)
        self._yaml_template: dict = None
        self.add_step(YamlTemplateServiceAlaCarteInstantiateStep(cleanup))

    @property
    def yaml_template(self) -> dict:
        """Step YAML template.

        Load from file if it's a root step, get from parent otherwise.

        Returns:
            dict: Step YAML template

        """
        if self.is_root:
            if not self._yaml_template:
                with open(settings.SERVICE_YAML_TEMPLATE, "r") as yaml_template:
                    self._yaml_template: dict = load(yaml_template)
            return self._yaml_template
        return self.parent.yaml_template

    @property
    def service_name(self) -> str:
        """Service name.

        Get from YAML template if it's a root step, get from parent otherwise.

        Returns:
            str: Service name

        """
        if self.is_root:
            return next(iter(self.yaml_template.keys()))
        return self.parent.service_name

    @property
    def service_instance_name(self) -> str:
        """Service instance name.

        Generate using `service_name` and `uuid4()` function if it's a root step,
            get from parent otherwise.

        Returns:
            str: Service instance name

        """
        if self.is_root:
            return f"{self.service_name}-{str(uuid4())}"
        return self.parent.service_instance_name

    def execute(self):
        """Instantiate vnf.

        Use settings values:
         - GLOBAL_CUSTOMER_ID,
         - LINE_OF_BUSINESS.

        Raises:
            Exception: VNF instantiation failed

        """
        super().execute()
        service: Service = Service(self.service_name)
        customer: Customer = Customer.get_by_global_customer_id(settings.GLOBAL_CUSTOMER_ID)
        service_subscription: ServiceSubscription = customer.get_service_subscription_by_service_type(self.service_name)
        service_instance: ServiceInstance = service_subscription.get_service_instance_by_name(self.service_instance_name)
        line_of_business: LineOfBusiness = LineOfBusiness(settings.LINE_OF_BUSINESS)
        platform: Platform = Platform(settings.PLATFORM)
        for idx, vnf in service.vnfs:
            vnf_instantiation = service_instance.add_vnf(vnf, line_of_business, platform, f"{self.service_instance_name}_vnf_{idx}")
            while not vnf_instantiation.finished:
                time.sleep(10)
            if vnf_instantiation.failed:
                raise Exception("Vnf instantiation failed")