#!/usr/bin/env python
# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright (c) 2011 Openstack, LLC.
# All Rights Reserved.
#
#    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.

"""Cron script to generate usage notifications for volumes existing during
   the audit period.

   Together with the notifications generated by volumes
   create/delete/resize, over that time period, this allows an external
   system consuming usage notification feeds to calculate volume usage
   for each tenant.

   Time periods are specified as 'hour', 'month', 'day' or 'year'

   hour = previous hour. If run at 9:07am, will generate usage for 8-9am.
   month = previous month. If the script is run April 1, it will generate
           usages for March 1 through March 31.
   day = previous day. if run on July 4th, it generates usages for July 3rd.
   year = previous year. If run on Jan 1, it generates usages for
        Jan 1 through Dec 31 of the previous year.
"""

import datetime
import gettext
import os
import sys
import time
import traceback

# If ../nova/__init__.py exists, add ../ to Python search path, so that
# it will override what happens to be installed in /usr/(local/)lib/python...
POSSIBLE_TOPDIR = os.path.normpath(os.path.join(os.path.abspath(sys.argv[0]),
                                   os.pardir,
                                   os.pardir))
if os.path.exists(os.path.join(POSSIBLE_TOPDIR, 'nova', '__init__.py')):
    sys.path.insert(0, POSSIBLE_TOPDIR)

gettext.install('nova', unicode=1)
from nova import context
from nova import db
from nova import exception
from nova import flags
from nova.openstack.common import log as logging
from nova.openstack.common import rpc
from nova import utils
from nova.volume import utils as volume_utils

FLAGS = flags.FLAGS

if __name__ == '__main__':
    admin_context = context.get_admin_context()
    utils.default_cfgfile()
    flags.FLAGS(sys.argv)
    logging.setup("nova")
    begin, end = utils.last_completed_audit_period()
    print "Starting volume usage audit"
    print "Creating usages for %s until %s" % (str(begin), str(end))
    volumes = db.volume_get_active_by_window(admin_context,
                                             begin,
                                             end)
    print "Found %d volumes" % len(volumes)
    for volume_ref in volumes:
        try:
            volume_utils.notify_usage_exists(
                    admin_context, volume_ref)
        except Exception, e:
            print traceback.format_exc(e)
    print "Volume usage audit completed"