#!/usr/bin/env python
# Copyright 2013-2018 CERN for the benefit of the ATLAS collaboration.
#
# 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.
#
# Authors:
# - Vincent Garonne, <vgaronne@gmail.com>, 2013-2018
# - Mario Lassnig, <mario.lassnig@cern.ch>, 2018
# - Hannes Hansen, <hannes.jakob.hansen@cern.ch>, 2018
#
# PY3K COMPATIBLE

"""
Undertaker is a daemon to manage expired did.
"""

import argparse
import signal

from rucio.daemons.undertaker.undertaker import run, stop


def get_parser():
    """
    Returns the argparse parser.
    """
    parser = argparse.ArgumentParser(description="The Undertaker deamon is responsible for managing expired DIDs. It deletes DIDs, but not replicas by checking if there are DIDs where the 'expired_at' date property is older than the current timestamp.", epilog='''
Create a DID that is already expired by setting its lifetime to -1::

  $ python
  from rucio.db.sqla.constants import DIDType
  from rucio.client.didclient import DIDClient
  client = DIDClient()
  client.add_did(scope='mock', name='test', type=DIDType.DATASET, lifetime=-1)

Check if the DID exists::

  $ rucio list-dids mock:test
  +--------------+--------------+
  | SCOPE:NAME   | [DID TYPE]   |
  |--------------+--------------|
  | mock:test    | DATASET      |
  +--------------+--------------+

Run the daemon::

  $ rucio-undertaker --run-once

Check if the DID exists::

  $ rucio list-dids mock:test
  +--------------+--------------+
  | SCOPE:NAME   | [DID TYPE]   |
  |--------------+--------------|
  +--------------+--------------+
    ''')
    parser.add_argument("--run-once", action="store_true", default=False, help='One iteration only')
    parser.add_argument("--total-workers", action="store", default=1, type=int, help='Total number of workers')
    parser.add_argument("--chunk-size", action="store", default=5, type=int, help='Chunk size')
    return parser


if __name__ == "__main__":

    signal.signal(signal.SIGTERM, stop)
    parser = get_parser()
    args = parser.parse_args()
    try:
        run(total_workers=args.total_workers, chunk_size=args.chunk_size, once=args.run_once)
    except KeyboardInterrupt:
        stop()
