#!/usr/bin/python
#

# Copyright (C) 2006, 2007 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.

""" Ganeti Remote API master script.
"""

import glob
import optparse
import sys
import os

# we need to import rpc early in order to get our custom reactor,
# instead of the default twisted one; without this, things breaks in a
# not-nice-to-debug way
from ganeti import rpc
from ganeti import constants
from ganeti import utils
from ganeti.rapi import RESTHTTPServer


def ParseOptions():
  """Parse the command line options.

  Returns:
    (options, args) as from OptionParser.parse_args()

  """
  parser = optparse.OptionParser(description="Ganeti Remote API",
                    usage="%prog [-d] [-p port]",
                    version="%%prog (ganeti) %s" %
                                 constants.RAPI_VERSION)
  parser.add_option("-d", "--debug", dest="debug",
                    help="Enable some debug messages",
                    default=False, action="store_true")
  parser.add_option("-p", "--port", dest="port",
                    help="Port to run API (%s default)." %
                                 constants.RAPI_PORT,
                    default=constants.RAPI_PORT, type="int")
  parser.add_option("-S", "--https", dest="ssl",
                    help="Secure HTTP protocol with SSL",
                    default=False, action="store_true")
  parser.add_option("-K", "--ssl-key", dest="ssl_key",
                    help="SSL key",
                    default=None, type="string")
  parser.add_option("-C", "--ssl-cert", dest="ssl_cert",
                    help="SSL certificate",
                    default=None, type="string")
  parser.add_option("-f", "--foreground", dest="fork",
                    help="Don't detach from the current terminal",
                    default=True, action="store_false")

  options, args = parser.parse_args()

  if len(args) != 1 or args[0] not in ("start", "stop"):
    print >> sys.stderr, "Usage: %s [-d] [-p port] start|stop\n" % sys.argv[0]
    sys.exit(1)

  if options.ssl:
    if not (options.ssl_cert and options.ssl_key):
      print >> sys.stderr, ("For secure mode please provide "
                           "--ssl-key and --ssl-cert arguments")
      sys.exit(1)

  return options, args


def Port2PID(port):
  """Map network port to PID.

  Args:
    port: A port number to map.

  Return:
    PID number.
  """

  _NET_STAT = ['/proc/net/tcp', '/proc/net/udp']

  inode2port = {}
  port2pid = {}

  for file in _NET_STAT:
    try:
      try:
        f = open(file)
        for line in f.readlines()[1:]:
          d = line.split()
          inode2port[long(d[9])] = int(d[1].split(':')[1], 16)
      finally:
        f.close()
    except EnvironmentError:
      # Nothing can be done
      pass

  fdlist = glob.glob('/proc/[0-9]*/fd/*')
  for fd in fdlist:
    try:
      pid = int(fd.split('/')[2])
      inode = long(os.stat(fd)[1])
      if inode in inode2port:
        port2pid[inode2port[inode]] = pid
    except EnvironmentError:
      # Nothing can be done
      pass

  if port in port2pid:
    return port2pid[port]
  else:
    return None


def StartAPI(options):
  """Start the API.

  Args:
    options: arguments.

  Return:
    Exit code.
  """
  if options.fork:
    utils.Daemonize(logfile=constants.LOG_RAPISERVER)
  RESTHTTPServer.start(options)


def StopAPI(options):
  """Stop the API."""
  try:
    pid = Port2PID(options.port)
    if pid:
      print ("Stopping Ganeti-RAPI PID: %d, port: %d... "
             % (pid, options.port)),
      os.kill(pid, 9)
      print "done."
    else:
      print >> sys.stderr, "Unable to locate running Ganeti-RAPI on port: %d" \
          % options.port

  except Exception, ex:
    print >> sys.stderr, ex
    return 1
  return 0


def main():
  """Main function.

  """
  result = 1
  options, args = ParseOptions()
  if args[0] == "start":
    result = StartAPI(options)
  else:
    result = StopAPI(options)
  sys.exit(result)


if __name__ == '__main__':
  main()