#!/usr/bin/env python
# -*- encoding: utf-8 -*-
#
# Copyright © 2012 New Dream Network, LLC (DreamHost)
#
# Author: Doug Hellmann <doug.hellmann@dreamhost.com>
#
# 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.

"""Command line tool for recording notification messages and replaying
them later.
"""

import argparse
import logging
import cPickle as pickle
import sys

from nova import flags
from nova import utils

from ceilometer.openstack.common import cfg
from ceilometer.openstack.common import rpc

FLAGS = flags.FLAGS
LOG = logging.getLogger(__name__)


def record_messages(connection, topic, output):
    """Listen to notification.info messages and pickle them to output."""
    def process_event(body):
        print ('%s: %s' %
               (body.get('timestamp'),
                body.get('event_type', 'unknown event'),
                ))
        pickle.dump(body, output)

    connection.declare_topic_consumer(topic, process_event)
    try:
        connection.consume()
    except KeyboardInterrupt:
        pass


def monitor_messages(connection, topic):
    """Listen to notification.info messages and print them."""
    def process_event(msg):
        body = msg['args']['data']
        if 'resource_id' in body:
            print ('%s: %s/%-15s: %s' %
                   (body.get('timestamp'),
                    body.get('resource_id'),
                    body.get('event_type'),
                    body.get('counter_volume'),
                    ))
        else:
            print ('%s: %s' %
                   (body.get('timestamp'),
                    body.get('event_type'),
                    ))

    connection.declare_topic_consumer(topic, process_event)
    try:
        connection.consume()
    except KeyboardInterrupt:
        pass


def send_messages(connection, topic, input):
    """Read messages from the input and send them to the AMQP queue."""
    while True:
        try:
            body = pickle.load(input)
        except EOFError:
            break
        print('%s: %s' %
              (body.get('timestamp'),
               body.get('event_type', 'unknown event'),
               ))
        connection.topic_send(topic, body)


def main():
    rpc.register_opts(FLAGS)
    FLAGS.register_opts([
            cfg.StrOpt('datafile',
                       default=None,
                       help='Data file to read or write',
                       ),
            cfg.BoolOpt('record',
                        help='Record events',
                        ),
            cfg.BoolOpt('replay',
                        help='Replay events',
                        ),
            ])

    remaining_args = FLAGS(sys.argv)
    utils.monkey_patch()

    parser = argparse.ArgumentParser(
        description='record or play back notification events',
        )
    parser.add_argument('mode',
                        choices=('record', 'replay', 'monitor'),
                        help='operating mode',
                        )
    parser.add_argument('data_file',
                        default='msgs.dat',
                        nargs='?',
                        help='the data file to read or write',
                        )
    parser.add_argument('--topic',
                        default='notifications.info',
                        help='the exchange topic to listen for',
                        )
    args = parser.parse_args(remaining_args[1:])

    console = logging.StreamHandler(sys.stderr)
    console.setLevel(logging.DEBUG)
    formatter = logging.Formatter('%(message)s')
    console.setFormatter(formatter)
    root_logger = logging.getLogger('')
    root_logger.addHandler(console)
    root_logger.setLevel(logging.DEBUG)

    connection = rpc.create_connection()
    try:
        if args.mode == 'replay':
            with open(args.data_file, 'rb') as input:
                send_messages(connection, args.topic, input)
        elif args.mode == 'record':
            with open(args.data_file, 'wb') as output:
                record_messages(connection, args.topic, output)
        elif args.mode == 'monitor':
            monitor_messages(connection, args.topic)
    finally:
        connection.close()

    return 0

if __name__ == '__main__':
    main()