# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# 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.

from nova import exception


def ec2_id_to_id(ec2_id):
    """Convert an ec2 ID (i-[base 16 number]) to an instance id (int)"""
    try:
        return int(ec2_id.split('-')[-1], 16)
    except ValueError:
        raise exception.NotFound(_("Id %s Not Found") % ec2_id)


def id_to_ec2_id(instance_id, template='i-%08x'):
    """Convert an instance ID (int) to an ec2 ID (i-[base 16 number])"""
    return template % instance_id
