#!/usr/bin/python2 -u
# Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Exposes the FAFTClient interface over XMLRPC.

It launches an XMLRPC server and exposes the functions in RPCRouter().
"""

import logging
import os
from optparse import OptionParser

import psutil

import common
from autotest_lib.client.cros import xmlrpc_server
from autotest_lib.client.cros.faft.utils import os_interface
from autotest_lib.client.common_lib import logging_config


def terminate_old():
    """
    Avoid "address already in use" errors by killing any leftover RPC server
    processes, possibly from previous runs.

    A process is a match if it has the same executable and command line:
    /usr/local/bin/python2.7
    ['/usr/bin/python2', '-u', '/usr/local/autotest/cros/faft/rpc_server.py']
    """
    me = psutil.Process()
    for p in psutil.process_iter():
        if p == me:
            continue
        try:
            if p.exe() == me.exe() and p.cmdline() == me.cmdline():
                logging.info('Terminating leftover process: %s', p)
                try:
                    p.terminate()
                    p.wait(timeout=5)
                    logging.debug('Process exited')
                except psutil.TimeoutExpired as e:
                    logging.warn('Process did not exit, '
                                 'falling back to SIGKILL: %s', e)
                    try:
                        p.kill()
                        p.wait(timeout=2.5)
                        logging.debug('Process exited')
                    except psutil.TimeoutExpired as e:
                        logging.exception('Process did not exit; '
                                          'address may remain in use.')
        except psutil.AccessDenied:
            logging.exception('Process could not be terminated; '
                              'address may remain in use.')
        except psutil.NoSuchProcess as e:
            # process exited already
            logging.debug('Process exited: %s', e)


def main():
    """The Main program, to run the XMLRPC server."""
    parser = OptionParser(usage='Usage: %prog [options]')
    parser.add_option(
            '--port',
            type='int',
            dest='port',
            default=9990,
            help='port number of XMLRPC server')
    (options, _) = parser.parse_args()

    config = logging_config.LoggingConfig()
    config.configure_logging(use_console=True, verbose=True)

    logging.debug('faft.rpc_server[%s] main...', os.getpid())
    terminate_old()

    # Import after terminate, so old process is killed even if import fails
    from autotest_lib.client.cros.faft import rpc_functions

    # Launch the XMLRPC server to provide FAFTClient commands.
    os_if = os_interface.OSInterface()
    os.chdir(os_if.state_dir)

    server = xmlrpc_server.XmlRpcServer('localhost', options.port)
    router = rpc_functions.FaftXmlRpcDelegate(os_if)
    server.register_delegate(router)
    server.run()
    logging.debug('faft.rpc_server[%s] done.\n', os.getpid())


if __name__ == '__main__':
    main()