#!/usr/bin/env python
# Copyright 2012-2018 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>, 2012-2018
# - Cedric Serfon, <cedric.serfon@cern.ch>, 2013-2018
# - Mario Lassnig, <mario.lassnig@cern.ch>, 2015
#
# PY3K COMPATIBLE

'''
Transmogrifier (Replication Rule Resolver) Daemon
'''

import argparse
import signal

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


def get_parser():
    """
    Returns the argparse parser.
    """
    parser = argparse.ArgumentParser()
    parser = argparse.ArgumentParser(description="The Transmogrifier daemon is responsible for the creation of replication rules for DIDs matching a subscription.", epilog='''
Create a DID::

  $ python
  from rucio.core.did import add_did
  from rucio.db.sqla.constants import DIDType
  add_did(scope='mock', name='test', type=DIDType.DATASET, account='root', meta={'project': 'test_project'})

Create a subscription that matches the DID::

  $ rucio-admin subscription add test '{"scope": ["mock"], "project": ["test_project"]}' '[{"copies": 1, "rse_expression": "MOCK", "activity": "User Subscriptions"}]' 'df'

Check if there are rules for the DID::

  $ rucio list-rules mock:test
  ID                                ACCOUNT    SCOPE:NAME    STATE[OK/REPL/STUCK]    RSE_EXPRESSION      COPIES  EXPIRES (UTC)    CREATED (UTC)
  --------------------------------  ---------  ------------  ----------------------  ----------------  --------  ---------------  -------------------

Run the daemon::

  $ rucio-transmogrifier --run-once

Check again if there are rules for the DID::

  $ rucio list-rules mock:test
  ID                                ACCOUNT    SCOPE:NAME    STATE[OK/REPL/STUCK]    RSE_EXPRESSION      COPIES  EXPIRES (UTC)    CREATED (UTC)
  --------------------------------  ---------  ------------  ----------------------  ----------------  --------  ---------------  -------------------
  e658f6f47f444326aad624dabef7b785  root       mock:test     OK[0/0/0]               MOCK                     1                   2018-12-03 14:01:19
    ''')
    parser.add_argument("--run-once", action="store_true", default=False, help='Runs one loop iteration')
    parser.add_argument("--threads", action="store", default=1, type=int, help='Concurrency control: number of threads')
    parser.add_argument("--bulk", action="store", default=1000, type=int, help='Bulk control: number of requests per cycle')
    parser.add_argument('--sleep-time', action="store", default=60, type=int, help='Seconds to sleep between two cycles')
    return parser


if __name__ == "__main__":

    # Bind our callback to the SIGTERM signal and run the daemon:
    signal.signal(signal.SIGTERM, stop)

    parser = get_parser()
    args = parser.parse_args()
    try:
        run(once=args.run_once, threads=args.threads, bulk=args.bulk, sleep_time=args.sleep_time)
    except KeyboardInterrupt:
        stop()
