#!/usr/bin/python
# Copyright (C) 2012-2013  Codethink Limited
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.


'''A Morph deployment write extension for deploying to VirtualBox via ssh.

VirtualBox is assumed to be running on a remote machine, which is
accessed over ssh. The machine gets created, but not started.

'''


import cliapp
import os
import re
import sys
import time
import tempfile
import urlparse

import morphlib.writeexts


class VirtualBoxPlusSshWriteExtension(morphlib.writeexts.WriteExtension):

    '''Create a VirtualBox virtual machine during Morph's deployment.
    
    The location command line argument is the pathname of the disk image
    to be created. The user is expected to provide the location argument
    using the following syntax:
    
        vbox+ssh://HOST/GUEST/PATH
        
    where:
    
    * HOST is the host on which VirtualBox is running
    * GUEST is the name of the guest virtual machine on that host
    * PATH is the path to the disk image that should be created,
      on that host
  
    The extension will connect to HOST via ssh to run VirtualBox's
    command line management tools.
    
    '''

    def process_args(self, args):
        if len(args) != 2:
            raise cliapp.AppException('Wrong number of command line args')
        
        temp_root, location = args
        ssh_host, vm_name, vdi_path = self.parse_location(location)
        autostart = self.parse_autostart()
        
        fd, raw_disk = tempfile.mkstemp()
        os.close(fd)
        self.create_local_system(temp_root, raw_disk)

        try:
            self.transfer_and_convert_to_vdi(
                raw_disk, ssh_host, vdi_path)
            self.create_virtualbox_guest(ssh_host, vm_name, vdi_path,
                                         autostart)
        except BaseException:
            sys.stderr.write('Error deploying to VirtualBox')
            os.remove(raw_disk)
            raise
        else:
            os.remove(raw_disk)

        self.status(
            msg='Virtual machine %(vm_name)s has been created',
            vm_name=vm_name)

    def parse_location(self, location):
        '''Parse the location argument to get relevant data.'''
        
        x = urlparse.urlparse(location)
        if x.scheme != 'vbox+ssh':
            raise cliapp.AppException(
                'URL schema must be vbox+ssh in %s' % location)
        m = re.match('^/(?P<guest>[^/]+)(?P<path>/.+)$', x.path)
        if not m:
            raise cliapp.AppException('Cannot parse location %s' % location)
        return x.netloc, m.group('guest'), m.group('path')

    def transfer_and_convert_to_vdi(self, raw_disk, ssh_host, vdi_path):
        '''Transfer raw disk image to VirtualBox host, and convert to VDI.'''

        self.status(msg='Transfer disk and convert to VDI')
        with open(raw_disk, 'rb') as f:
            cliapp.runcmd(
                ['ssh', ssh_host, 
                 'VBoxManage', 'convertfromraw', 'stdin', vdi_path,
                 str(os.path.getsize(raw_disk))],
                stdin=f)

    def create_virtualbox_guest(self, ssh_host, vm_name, vdi_path, autostart):
        '''Create the VirtualBox virtual machine.'''
        
        self.status(msg='Create VirtualBox virtual machine')

        ram_mebibytes = str(self.get_ram_size() / (1024**2))

        commands = [
            ['createvm', '--name', vm_name, '--ostype', 'Linux26_64',
             '--register'],
            ['modifyvm', vm_name, '--ioapic', 'on', '--memory', ram_mebibytes,
             '--nic1', 'nat'],
            ['storagectl', vm_name, '--name', '"SATA Controller"',
             '--add', 'sata',  '--bootable', 'on', '--sataportcount', '2'],
            ['storageattach', vm_name, '--storagectl', '"SATA Controller"',
             '--port', '0', '--device', '0', '--type', 'hdd', '--medium',
             vdi_path],
        ]

        attach_disks = self.parse_attach_disks()
        for device_no, disk in enumerate(attach_disks, 1):
            cmd = ['storageattach', vm_name, 
                   '--storagectl', '"SATA Controller"',
                   '--port', str(device_no),
                   '--device', '0',
                   '--type', 'hdd', 
                   '--medium', disk]
            commands.append(cmd)

        if autostart:
            commands.append(['startvm', vm_name])

        for command in commands:
            argv = ['ssh', ssh_host, 'VBoxManage'] + command
            cliapp.runcmd(argv)


VirtualBoxPlusSshWriteExtension().run()