#! /usr/bin/python -E
#
# Copyright (C) 2007  Red Hat
# see file 'COPYING' for use and warranty information
#
# 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 only
#
# 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#

import os, sys, pwd, grp
from optparse import OptionParser
import traceback
import logging
import signal

def usage():
    print "ipa_webgui [-f|--foreground] [-d|--debug]"
    sys.exit(1)

def parse_options():
    parser = OptionParser()
    parser.add_option("-f", "--foreground", dest="foreground",
                      action="store_true", default=False,
                      help="Remain in the foreground")
    parser.add_option("-d", "--debug", dest="debug", action="store_true",
                      default=False,
                      help="Increase the amount of logging information")
    parser.add_option("--usage", action="store_true",
                      help="Program usage")

    options, args = parser.parse_args(sys.argv)

    return options, args

def daemonize():
    # fork once so the parent can exit
    try:
        pid = os.fork()
    except OSError, e:
        raise Exception, "%s [%d]" % (e.strerror, e.errno)

    if pid != 0:
        os._exit(0)

    # become session leader
    os.setsid()
    
    # fork again to reparent to init
    try:
        pid = os.fork()
    except OSError, e:
        raise Exception, "%s [%d]" % (e.strerror, e.errno)

    if pid != 0:
        os._exit(0)

    os.chdir("/")
    os.umask(0)

    import resource
    maxfd = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
    if (maxfd == resource.RLIM_INFINITY):
        maxfd = 1024
      
    # close all file descriptors
    for fd in range(0, maxfd):
        try:
            os.close(fd)
        except OSError:
            pass

    # stdin
    os.open("/dev/null", os.O_RDWR)
    # stdout
    os.open("/dev/null", os.O_RDWR)
    # stderr
    os.open("/dev/null", os.O_RDWR)

def main():
    options, args = parse_options()

    foreground = options.foreground

    if options.debug:
        loglevel = logging.DEBUG
    else:
        loglevel = logging.WARN
    
    # To make development easier, we detect if we are in the development
    # environment to load a different configuration and avoid becoming
    # a daemon
    devel = False
    if os.path.exists(os.path.join(os.path.dirname(__file__), "Makefile.am")):
        devel = True
        foreground = True

    if not foreground:
        try:
            daemonize()
        except Exception, e:
            sys.stderr.write("error becoming daemon: " + str(e))
            sys.exit(1)

    if not foreground:
        try:
            daemonize()
        except Exception, e:
            sys.stderr.write("error becoming daemon: " + str(e))
            sys.exit(1)

    # Drop privileges and write our pid file only if we're running as root
    if os.getuid() == 0:
        # Write out our pid file
        pidfile = open("/var/run/ipa_webgui.pid", "w")
        pidfile.write(str(os.getpid()))
        pidfile.close()

        # Drop privs
        apache_uid = pwd.getpwnam("apache")[2]
        apache_gid = grp.getgrnam("apache")[2]

        try:
            os.setgid(apache_gid)
        except OSError, e:
            log.error("Could not set effective group id: %s" % e)

        try:
            os.setuid(apache_uid)
        except OSError, e:
            log.error("Could not set effective user id: %s" % e)

    if foreground:
        logging.basicConfig(level=loglevel,
                            format='%(asctime)s %(name)s %(levelname)s %(message)s',
                            stream=sys.stderr)
    else:
        # This log file name needs to be kept in sync with the one in
        # ipa_webgui.cfg
        logging.basicConfig(level=loglevel,
                            format='%(asctime)s %(name)s %(levelname)s %(message)s',
                            filename='/var/log/ipa_error.log')

    sys.path.append("/usr/share/ipa")

    # this must be after sys.path is changed to work correctly
    import pkg_resources
    pkg_resources.require("TurboGears")
    pkg_resources.require("ipa_gui")

    from turbogears import update_config, start_server
    from turbogears.config import update
    import cherrypy
    cherrypy.lowercase_api = True

    try:
        if hasattr(signal, "SIGTERM"):
            def SIGTERM(signum=None, frame=None):
                cherrypy.server.stop()
            signal.signal(signal.SIGTERM, SIGTERM)
    except ValueError, _signal_exc:
        if _signal_exc.args[0] != "signal only works in main thread":
            raise


    # Shut down the logging set up here so that CherryPy logging can take
    # over. TurboGears configuration errors will not be caught.
    if not foreground:
        logging.shutdown()

    # Load the config - look for a local file first for development
    # and then the system config file
    if devel:
        update_config(configfile="dev.cfg",
                      modulename="ipagui.config")
        update( { "i18n.locale_dir": "locales"} )
    else:
        update_config(configfile="/usr/share/ipa/ipa_webgui.cfg",
                      modulename="ipagui.config.app")
        update( { "i18n.locale_dir": "/usr/share/ipa/locales"} )

    from ipagui.controllers import Root

    start_server(Root())

try:
    main()
    sys.exit(0)
except SystemExit, e:
    sys.exit(e)
except Exception, e:
    message = "failed to start web gui: %s" % str(e)
    print message
    for str in traceback.format_tb(sys.exc_info()[2]):
        message = message + "\n" + str
    logging.error(message)

    sys.exit(1)