# Copyright 2018 AT&T Intellectual Property.  All other rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from airflow.models import DAG
from airflow.operators import DrydockDestroyNodeOperator
from airflow.operators import PromenadeCheckEtcdOperator
from airflow.operators import PromenadeClearLabelsOperator
from airflow.operators import PromenadeDecommissionNodeOperator
from airflow.operators import PromenadeDrainNodeOperator
from airflow.operators import PromenadeShutdownKubeletOperator

from config_path import config_path


def destroy_server(parent_dag_name, child_dag_name, args):
    """DAG to tear down node

    The DAG will make use of the promenade and drydock operators
    to tear down a target node.

    """
    dag = DAG(
        '{}.{}'.format(parent_dag_name, child_dag_name),
        default_args=args)

    # Drain Node
    promenade_drain_node = PromenadeDrainNodeOperator(
        task_id='promenade_drain_node',
        shipyard_conf=config_path,
        main_dag_name=parent_dag_name,
        sub_dag_name=child_dag_name,
        dag=dag)

    # Clear Labels
    promenade_clear_labels = PromenadeClearLabelsOperator(
        task_id='promenade_clear_labels',
        shipyard_conf=config_path,
        main_dag_name=parent_dag_name,
        sub_dag_name=child_dag_name,
        dag=dag)

    # Shutdown Kubelet
    promenade_shutdown_kubelet = PromenadeShutdownKubeletOperator(
        task_id='promenade_shutdown_kubelet',
        shipyard_conf=config_path,
        main_dag_name=parent_dag_name,
        sub_dag_name=child_dag_name,
        dag=dag)

    # ETCD Sanity Check
    promenade_check_etcd = PromenadeCheckEtcdOperator(
        task_id='promenade_check_etcd',
        shipyard_conf=config_path,
        main_dag_name=parent_dag_name,
        sub_dag_name=child_dag_name,
        dag=dag)

    # Power down and destroy node using DryDock
    drydock_destroy_node = DrydockDestroyNodeOperator(
        task_id='destroy_node',
        shipyard_conf=config_path,
        main_dag_name=parent_dag_name,
        sub_dag_name=child_dag_name,
        dag=dag)

    # Decommission node from Kubernetes cluster using Promenade
    promenade_decommission_node = PromenadeDecommissionNodeOperator(
        task_id='promenade_decommission_node',
        shipyard_conf=config_path,
        main_dag_name=parent_dag_name,
        sub_dag_name=child_dag_name,
        dag=dag)

    # Define dependencies
    promenade_clear_labels.set_upstream(promenade_drain_node)
    promenade_shutdown_kubelet.set_upstream(promenade_clear_labels)
    promenade_check_etcd.set_upstream(promenade_shutdown_kubelet)
    drydock_destroy_node.set_upstream(promenade_check_etcd)
    promenade_decommission_node.set_upstream(drydock_destroy_node)

    return dag