#!/usr/bin/python
#
# An applet to monitor /etc/nologin

import gio
import dbus
import dbus.mainloop.glib
import gtk
import gobject
import sys
import os
import subprocess
import time
from optparse import OptionParser

SM_DBUS_NAME = "org.gnome.SessionManager"
SM_DBUS_PATH = "/org/gnome/SessionManager"
SM_DBUS_INTERFACE = "org.gnome.SessionManager"
SM_CLIENT_DBUS_INTERFACE = "org.gnome.SessionManager.ClientPrivate"
APP_ID = "debathena-nologin-monitor"

class GDMSucks:
    def __init__(self, options):
        self.debug = options.debug
        self.guitest = options.guitest
        self.sessionEnding = False
        self.sessionBus = dbus.SessionBus()
        try:
            self.register_with_sm()
            self.init_sm_client()
        except:
            print "Warning: Cannot register with session manager."
        
        self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)
        self.window.set_property('can-focus', False)
        box = gtk.VBox()
        self.label = gtk.Label()
        self.label.set_markup('<span font_desc="Sans Bold 24">Software updates are being applied.\n\nThis workstation is temporarily unavailable.\n\nPlease use another workstation.\n\n</span>(Update started at %s)' % (time.strftime("%Y-%m-%d %H:%M")))
        self.label.set_property('can-focus', False)
        self.label.set_justify(gtk.JUSTIFY_CENTER)
        box.pack_start(self.label, True, True, 5)
        self.window.add(box)
        self.window.set_size_request(800, 600)
        self.window.set_decorated(False)
        self.window.set_position(gtk.WIN_POS_CENTER)
        self.window.hide()
        if self.guitest:
            self.window.show_all()
        try:
            metapackage = subprocess.Popen(["machtype", "-L"], stdout=subprocess.PIPE).communicate()[0].rstrip()
        except OSError:
            # Assume cluster
            metapackage = 'debathena-cluster'
        if (self.debug or metapackage == 'debathena-cluster') and os.path.isfile("/var/run/athena-nologin"):
            self.window.show_all()
        if self.debug or metapackage == 'debathena-cluster':
            self.gfile = gio.File("/var/run/athena-nologin")
            self.monitor = self.gfile.monitor_file(gio.FILE_MONITOR_NONE, None)
            self.monitor.connect("changed", self.directory_changed)

    def directory_changed(self, monitor, file1, file2, evt_type):
        if self.debug:
            print str(evt_type), file1.get_path()
        if evt_type == gio.FILE_MONITOR_EVENT_CREATED:
            self.label.set_markup('<span font_desc="Sans Bold 24">Software updates are being applied.\n\nThis workstation is temporarily unavailable.\n\nPlease use another workstation.\n\n</span>(Update started at %s)' % (time.strftime("%Y-%m-%d %H:%M")))
            self.window.show_all()
        if evt_type == gio.FILE_MONITOR_EVENT_DELETED:
            self.window.hide()

   # Connect to the session manager, and register our client.
    def register_with_sm(self):
        proxy = self.sessionBus.get_object(SM_DBUS_NAME, SM_DBUS_PATH)
        sm = dbus.Interface(proxy, SM_DBUS_INTERFACE)
        autostart_id = os.getenv("DESKTOP_AUTOSTART_ID", default="")
        self.smClientId = sm.RegisterClient(APP_ID, autostart_id)

    # Set up to handle signals from the session manager.
    def init_sm_client(self):
        proxy = self.sessionBus.get_object(SM_DBUS_NAME, self.smClientId)
        self.smClient = dbus.Interface(proxy, SM_CLIENT_DBUS_INTERFACE)
        self.smClient.connect_to_signal("QueryEndSession",
                                         self.sm_on_QueryEndSession)
        self.smClient.connect_to_signal("EndSession", self.sm_on_EndSession)
        self.smClient.connect_to_signal("CancelEndSession",
                                         self.sm_on_CancelEndSession)
        self.smClient.connect_to_signal("Stop", self.sm_on_Stop)

     # Here on a QueryEndSession signal from the session manager.
    def sm_on_QueryEndSession(self, flags):
        self.sessionEnding = True
        # Response args: is_ok, reason.
        self.smClient.EndSessionResponse(True, "")

    # Here on an EndSession signal from the session manager.
    def sm_on_EndSession(self, flags):
        self.sessionEnding = True
        # Response args: is_ok, reason.
        self.smClient.EndSessionResponse(True, "")

    # Here on a CancelEndSession signal from the session manager.
    def sm_on_CancelEndSession(self):
        self.sessionEnding = False

    # Here on a Stop signal from the session manager.
    def sm_on_Stop(self):
        gtk.main_quit()

def main(options):
    dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
    GDMSucks(options)
    gtk.main()

if __name__ == '__main__':
    parser = OptionParser()
    parser.set_defaults(debug=False, guitest=False)
    parser.add_option("--test", action="store_true", dest="debug")
    parser.add_option("--test-gui", action="store_true", dest="guitest")
    (options, args) = parser.parse_args()
    main(options)