#!/usr/bin/env python
#
# Created as part of the StratusLab project (http://stratuslab.eu),
# co-funded by the European Commission under the Grant Agreement
# INFSO-RI-261552."
#
# Copyright (c) 2011, Centre National de la Recherche Scientifique (CNRS)
#
# 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.
#

import os
import sys
from optparse import OptionParser

sys.path.append('/var/lib/stratuslab/python')

from stratuslab.CloudConnectorFactory import CloudConnectorFactory
from stratuslab.Util import modulePath, printError
from stratuslab.commandbase.StorageCommand import StorageCommand
from stratuslab.AuthnCommand import AuthnCommand
from stratuslab.PersistentDisk import PersistentDisk
from stratuslab.ConfigHolder import ConfigHolder
from stratuslab.Authn import AuthnFactory
from stratuslab.Exceptions import OneException


class MainProgram(AuthnCommand, StorageCommand):
    '''A command-line program to detach a persistent disk.'''

    def __init__(self):
        super(MainProgram, self).__init__()
        
    def parse(self):
        self.parser.usage = '%prog volume_uuid ... [options]'
        self.parser.description = '''Detach a hot plugged persistent disk on a running VM'''
        
        self.parser.add_option('-i', '--instance', dest='instance',
                help='The ID of the instance to which the volume attaches', metavar='VM_ID',
                default=0, type='int')

        StorageCommand.addPDiskEndpointOptions(self.parser)
        AuthnCommand.addCloudEndpointOptions(self.parser)

        super(MainProgram, self).parse()
        
        self.options, self.uuids = self.parser.parse_args()

    def checkOptions(self):
        super(MainProgram, self).checkOptions()
        if not self.uuids:
            printError('Please provide at least one persistent disk UUID to detach')
        if (self.options.instance < 0):
            printError('Please provide a VM ID on which to detach disk')
        try:
            self._retrieveVmNode()
        except OneException, e: 
            printError(e)
            
    def _retrieveVmNode(self):
        credentials = AuthnFactory.getCredentials(self.options)
        self.options.cloud = CloudConnectorFactory.getCloud(credentials)
        self.options.cloud.setEndpoint(self.options.endpoint)
        self.node = self.options.cloud.getVmNode(self.options.instance)
        
    def doWork(self):
        configHolder = ConfigHolder(self.options.__dict__, self.config or {})
        configHolder.pdiskProtocol = "https"
        pdisk = PersistentDisk(configHolder)
        for uuid in self.uuids:
            try:
                target = pdisk.hotDetach(self.options.instance, uuid)
                print 'DETACHED %s from VM %s on /dev/%s' % (uuid, self.options.instance, target)
            except Exception, e:
                printError('DISK %s: %s' % (uuid, e), exit=False)

if __name__ == '__main__':
    try:
        MainProgram()
    except KeyboardInterrupt:
        print '\n\nExecution interrupted by the user... goodbye!'
