# -*- coding: utf-8 -*-
#
# Licensed to the Apache Software Foundation (ASF) under one
# 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
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# under the License.
"""Pool APIs."""
from airflow.exceptions import AirflowBadRequest, PoolNotFound
from airflow.models import Pool
from airflow.utils.db import provide_session


@provide_session
def get_pool(name, session=None):
    """Get pool by a given name."""
    if not (name and name.strip()):
        raise AirflowBadRequest("Pool name shouldn't be empty")

    pool = session.query(Pool).filter_by(pool=name).first()
    if pool is None:
        raise PoolNotFound("Pool '%s' doesn't exist" % name)

    return pool


@provide_session
def get_pools(session=None):
    """Get all pools."""
    return session.query(Pool).all()


@provide_session
def create_pool(name, slots, description, session=None):
    """Create a pool with a given parameters."""
    if not (name and name.strip()):
        raise AirflowBadRequest("Pool name shouldn't be empty")

    try:
        slots = int(slots)
    except ValueError:
        raise AirflowBadRequest("Bad value for `slots`: %s" % slots)

    session.expire_on_commit = False
    pool = session.query(Pool).filter_by(pool=name).first()
    if pool is None:
        pool = Pool(pool=name, slots=slots, description=description)
        session.add(pool)
    else:
        pool.slots = slots
        pool.description = description

    session.commit()

    return pool


@provide_session
def delete_pool(name, session=None):
    """Delete pool by a given name."""
    if not (name and name.strip()):
        raise AirflowBadRequest("Pool name shouldn't be empty")

    if name == Pool.DEFAULT_POOL_NAME:
        raise AirflowBadRequest("default_pool cannot be deleted")

    pool = session.query(Pool).filter_by(pool=name).first()
    if pool is None:
        raise PoolNotFound("Pool '%s' doesn't exist" % name)

    session.delete(pool)
    session.commit()

    return pool
