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# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you 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 operator import attrgetter

from flask import current_app

from airflow import DAG
from airflow.api_connexion import security
from airflow.api_connexion.exceptions import BadRequest, NotFound
from airflow.api_connexion.schemas.task_schema import TaskCollection, task_collection_schema, task_schema
from airflow.exceptions import TaskNotFound
from airflow.security import permissions


@security.requires_access(
    [
        (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
        (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
    ]
)
def get_task(dag_id, task_id):
    """Get simplified representation of a task."""
    dag: DAG = current_app.dag_bag.get_dag(dag_id)
    if not dag:
        raise NotFound("DAG not found")

    try:
        task = dag.get_task(task_id=task_id)
    except TaskNotFound:
        raise NotFound("Task not found")
    return task_schema.dump(task)


@security.requires_access(
    [
        (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
        (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
    ]
)
def get_tasks(dag_id, order_by='task_id'):
    """Get tasks for DAG"""
    dag: DAG = current_app.dag_bag.get_dag(dag_id)
    if not dag:
        raise NotFound("DAG not found")
    tasks = dag.tasks

    try:
        tasks = sorted(tasks, key=attrgetter(order_by.lstrip('-')), reverse=(order_by[0:1] == '-'))
    except AttributeError as err:
        raise BadRequest(detail=str(err))
    task_collection = TaskCollection(tasks=tasks, total_entries=len(tasks))
    return task_collection_schema.dump(task_collection)