#!/usr/bin/python
#

# Copyright (C) 2007, 2008 Google Inc.
#
# 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; either version 2 of the License, or
# (at your option) any later version.
#
# 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.


"""Tool to upgrade the configuration file.

This code handles only the types supported by simplejson. As an example, "set"
is a "list".

"""


import os
import os.path
import sys
import optparse
import tempfile
import simplejson

from ganeti import utils
from ganeti import cli


options = None
args = None


class Error(Exception):
  """Generic exception"""
  pass


def ReadConfig(path):
  """Reads configuration file.

  """
  f = open(path, 'r')
  try:
    return simplejson.load(f)
  finally:
    f.close()


def WriteConfig(path, data):
  """Writes the configuration file.

  """
  if not options.dry_run:
    utils.CreateBackup(path)

  (fd, name) = tempfile.mkstemp(dir=os.path.dirname(path))
  f = os.fdopen(fd, 'w')
  try:
    try:
      simplejson.dump(data, f)
      f.flush()
      if options.dry_run:
        os.unlink(name)
      else:
        os.rename(name, path)
    except:
      os.unlink(name)
      raise
  finally:
    f.close()


def UpdateFromVersion2To3(cfg):
  """Updates the configuration from version 2 to 3.

  """
  if cfg['cluster']['config_version'] != 2:
    return

  # Add port pool
  if 'tcpudp_port_pool' not in cfg['cluster']:
    cfg['cluster']['tcpudp_port_pool'] = []

  # Add bridge settings
  if 'default_bridge' not in cfg['cluster']:
    cfg['cluster']['default_bridge'] = 'xen-br0'
  for inst in cfg['instances'].values():
    for nic in inst['nics']:
      if 'bridge' not in nic:
        nic['bridge'] = None

  cfg['cluster']['config_version'] = 3


# Main program
if __name__ == "__main__":
  program = os.path.basename(sys.argv[0])

  # Option parsing
  parser = optparse.OptionParser(usage="%prog [options] <config-file>")
  parser.add_option('--dry-run', dest='dry_run',
                    action="store_true",
                    help="Try to do the conversion, but don't write"
                         " output file")
  parser.add_option(cli.FORCE_OPT)
  parser.add_option('--verbose', dest='verbose',
                    action="store_true",
                    help="Verbose output")
  (options, args) = parser.parse_args()

  # Option checking
  if args:
    cfg_file = args[0]
  else:
    raise Error("Configuration file not specified")

  if not options.force:
    usertext = ("%s MUST run on the master node. Is this the master"
                " node?" % program)
    if not cli.AskUser(usertext):
      sys.exit(1)

  config = ReadConfig(cfg_file)

  if options.verbose:
    import pprint
    print "Before upgrade:"
    pprint.pprint(config)
    print

  UpdateFromVersion2To3(config)

  if options.verbose:
    print "After upgrade:"
    pprint.pprint(config)
    print

  WriteConfig(cfg_file, config)

  print "The configuration file has been updated successfully. Please run"
  print "  gnt-cluster copyfile %s" % cfg_file
  print "now."

# vim: set foldmethod=marker :