#!/bin/sh
#---------------------------------------------
#   xdg-screensaver
#
#   Utility script to control screensaver.
#
#   Refer to the usage() function below for usage.
#
#   Copyright 2006, Bryce Harrington <bryce@osdl.org>
#
#   LICENSE:
#
#---------------------------------------------

manualpage()
{
cat << '_MANUALPAGE'
_MANUALPAGE
}

usage()
{
cat << '_USAGE'
_USAGE
}

#@xdg-utils-common@

# Check if we can use "mv -T"
if mv -T ... ... 2>&1 | grep '\.\.\.' > /dev/null ; then
   # We can securely move files in /tmp with mv -T
   DEBUG 1 "mv -T available"
   MV="mv -T"
   screensaver_file="/tmp/xdg-screensaver-$USER-"`echo $DISPLAY | sed 's/:/-/g'`
else
   # No secure moves available, use home dir
   DEBUG 1 "mv -T not available"
   MV="mv"
   screensaver_file="$HOME/.xdg-screensaver-"`echo "$(hostname)"-$DISPLAY | sed 's/:/-/g'`
fi
lockfile_command=`command -v lockfile`

lockfile()
{
  if [ -n "$lockfile_command" ] ; then
     $lockfile_command -1 -l 10 -s 3 "$screensaver_file".lock
  else
     # Poor man's attempt at doing a lockfile
     # Be careful not to facilitate a symlink attack
     local try
     try=0
     while ! ln -s "$screensaver_file".lock "$screensaver_file".lock 2> /dev/null;
     do
        sleep 1
        try=$(($try+1))
        if [ $try -eq 3 ] ; then
            rm -f "$screensaver_file".lock || return # Can't remove lockfile
            try=0
        fi
     done
  fi
}

unlockfile()
{
  rm -f "$screensaver_file".lock
}

perform_action()
{
  result=1

  if [ "$1" = "resume" ] ; then
      # Restore DPMS state
      if [ -f "$screensaver_file.dpms" ]; then
          rm "$screensaver_file.dpms"
          # Re-enable DPMS
          xset +dpms
      fi
  fi
  if [ "$1" = "reset" ] ; then
      if xset -q | grep 'DPMS is Enabled' > /dev/null 2> /dev/null; then
          xset -dpms
          xset +dpms
          xset dpms force on
      fi
  fi

  case "$DE" in
    kde)
      if [ -n "${KDE_SESSION_VERSION}" ]; then
        screensaver_freedesktop "$1"
      else
        screensaver_kde3 "$1"
      fi
      ;;

    gnome3)
      screensaver_freedesktop "$1"
      ;;

    gnome_screensaver)
      screensaver_gnome_screensaver "$1"
      ;;

    mate_screensaver)
      screensaver_mate_screensaver "$1"
      ;;

    cinnamon)
      screensaver_cinnamon_screensaver "$1"
      ;;

    xscreensaver)
      screensaver_xscreensaver "$1"
      ;;

    xautolock_screensaver)
      xautolock_screensaver "$1"
      ;;

    xfce)
      [ -n "$DISPLAY" ] && screensaver_xserver "$1"
      ;;

    ''|generic)
      [ -n "$DISPLAY" ] && screensaver_xserver "$1"
      ;;
  esac

  if [ -n "$DISPLAY" ] && [ "$1" = "suspend" ] ; then
      # Save DPMS state
      if xset -q | grep 'DPMS is Enabled' > /dev/null 2> /dev/null; then
          test "${TMPDIR+set}" = set || TMPDIR=/tmp
          tmpfile=`mktemp $TMPDIR/tmp.XXXXXXXXXX`
          $MV "$tmpfile" "$screensaver_file.dpms"
          # Disable DPMS
          xset -dpms
      fi
  fi

}

cleanup_suspend()
{
  lockfile
  test "${TMPDIR+set}" = set || TMPDIR=/tmp
  tmpfile=`mktemp $TMPDIR/tmp.XXXXXXXXXX`
  grep -v "$window_id:$xprop_pid\$" "$screensaver_file" > "$tmpfile" 2> /dev/null
  $MV "$tmpfile" "$screensaver_file"
  if [ ! -s "$screensaver_file" ] ; then
      rm "$screensaver_file"
      unlockfile
      # $screensaver_file is empty, do resume
      perform_action resume
  else
      unlockfile
  fi
}

do_resume()
{
  lockfile # Obtain lockfile
  # Find the PID of the trackingprocess
  xprop_pid=`grep "$window_id:" "$screensaver_file" 2> /dev/null | cut -d ':' -f 2`
  unlockfile # Free lockfile
  if [ -n "$xprop_pid" ] && ps -p "$xprop_pid" 2> /dev/null | grep xprop > /dev/null; then
     # Kill the tracking process
     kill -s TERM $xprop_pid
  fi
  cleanup_suspend
}

XPROP=`command -v xprop`

check_window_id()
{
  if [ -z "$XPROP" ]; then
     DEBUG 3 "xprop not found"
     return
  fi
  DEBUG 2 "Running $XPROP -id $window_id"
  if $XPROP -id $window_id > /dev/null 2> /dev/null; then
     DEBUG 3 Window $window_id exists
  else
     DEBUG 3 Window $window_id does not exist
     exit_failure_operation_failed "Window $window_id does not exist"
  fi
}

track_window()
{
  if [ -z "$XPROP" ]; then
     # Don't track window if we don't have xprop
     return
  fi
  lockfile

  test "${TMPDIR+set}" = set || TMPDIR=/tmp
  tmpfile=`mktemp $TMPDIR/tmp.XXXXXXXXXX`
  # Filter stale entries from the xdg-screensaver status file
  # Return if $window_id is being tracked already
  (
    already_tracked=1
    IFS_save="$IFS"
    IFS=":"
    while read wid pid; do
      if ps -p "$pid" 2> /dev/null | grep xprop > /dev/null; then
        echo "$wid:$pid"
        if [ $wid = $window_id ] ; then
          already_tracked=0
        fi
      fi
    done
    IFS="$IFS_save"
    exit $already_tracked
  ) < $screensaver_file > $tmpfile
  already_tracked=$?

  if [ "$already_tracked" -eq "0" ] ; then
    $MV "$tmpfile" "$screensaver_file"
    # We are already tracking $window_id, don't do anything
    unlockfile
    return
  fi

  # Start tracking $window_id
  $XPROP -id $window_id -spy > /dev/null &
  xprop_pid=$!
  # Add window_id and xprop_pid to the xdg-screensave status file
  echo "$window_id:$xprop_pid" >> $tmpfile
  $MV "$tmpfile" "$screensaver_file"
  unlockfile
  # Wait for xprop to exit, it means that the window disappeared
  wait $xprop_pid
  # Clean up the administration and resume the screensaver
  cleanup_suspend
}

screensaver_freedesktop()
{
    case "$1" in
        suspend)
        screensaver_dbus_process $window_id $screensaver_file "org.freedesktop.ScreenSaver" "/ScreenSaver"
        result=0
        ;;

        resume)
        # Automatic resume when $screensaver_file disappears
        result=0
        ;;

        activate)
        dbus-send --session \
                  --dest=org.freedesktop.ScreenSaver \
                  --type=method_call \
                  /ScreenSaver \
                  org.freedesktop.ScreenSaver.SetActive \
                  boolean:true \
                  2> /dev/null
        result=$?
        ;;

        lock)
        dbus-send --session \
                  --dest=org.freedesktop.ScreenSaver \
                  --type=method_call \
                  /ScreenSaver \
                  org.freedesktop.ScreenSaver.Lock \
                  2> /dev/null
        result=$?
        ;;

        reset)
        dbus-send --session \
                  --dest=org.freedesktop.ScreenSaver \
                  --type=method_call \
                  /ScreenSaver \
                  org.freedesktop.ScreenSaver.SimulateUserActivity \
                  2> /dev/null
        result=$?
        ;;

        status)
        raw_status=`dbus-send --session \
                          --dest=org.freedesktop.ScreenSaver \
                          --type=method_call \
                          --print-reply \
                          --reply-timeout=2000 \
                          /ScreenSaver \
                          org.freedesktop.ScreenSaver.GetActive`
        result=$?
        status=
        if [ x"$result" = "x0" ]; then
            status=`echo "$raw_status" | grep boolean | cut -d ' ' -f 5`
            result=$?
        fi
        if [ x"$status" = "xtrue" ] || [ x"$status" = "xfalse" ]; then
            echo "enabled"
        elif [ x"$result" != "x0" ]; then
            echo "ERROR: dbus org.freedesktop.ScreenSaver.GetActive returned '$status'" >&2
            return 1
        else
            echo "disabled"
        fi
        ;;

        *)
        echo "ERROR: Unknown command '$1'" >&2
        return 1
        ;;
    esac
}

screensaver_kde3()
{
    case "$1" in
        suspend)
        dcop kdesktop KScreensaverIface enable false > /dev/null
        result=$?
        ;;

        resume)
        dcop kdesktop KScreensaverIface configure > /dev/null
        result=$?
        ;;

        activate)
        dcop kdesktop KScreensaverIface save > /dev/null
        result=$?
        ;;

        lock)
        dcop kdesktop KScreensaverIface lock > /dev/null
        result=$?
        ;;

        reset)
        # Turns the screensaver off right now
        dcop kdesktop KScreensaverIface quit > /dev/null
        result=$?
        ;;

        status)
        status=`dcop kdesktop KScreensaverIface isEnabled`
        result=$?
        if [ x"$status" = "xtrue" ]; then
            echo "enabled"
        elif [ x"$status" = "xfalse" ]; then
            echo "disabled"
        else
            echo "ERROR: kdesktop KScreensaverIface isEnabled returned '$status'" >&2
            return 1
        fi
        ;;

        *)
        echo "ERROR: Unknown command '$1'" >&2
        return 1
        ;;
    esac
}

xset_screensaver_timeout()
{
  xset q | sed '/^Screen Saver:/,/^[^ ]/ { s/.*timeout: *\([0-9]*\).*/\1/; t }; d'
}

screensaver_xserver()
{
    case "$1" in
        suspend)
        timeout=`xset_screensaver_timeout`
        if [ "$timeout" -gt 0 ]; then
            echo "$timeout" > "$screensaver_file.xset"
            xset s off > /dev/null
        fi
        result=$?
        ;;

        resume)
        if [ -f "$screensaver_file.xset" ] ; then
            value=`cat "$screensaver_file.xset"`
            xset s $value > /dev/null
            rm -f "$screensaver_file.xset"
        fi
        result=$?
        ;;

        activate)
        xset s activate > /dev/null
        result=$?
        ;;

        reset)
        xset s reset > /dev/null
        result=$?
        ;;

        status)
        timeout=`xset_screensaver_timeout`
        result=$?
        if [ "$timeout" -gt 0 ]; then
            echo "enabled"
        elif [ "$timeout" -eq 0 ]; then
            echo "disabled"
        else
            echo "ERROR: xset q did not report the screensaver timeout" >&2
            return 1
        fi
        ;;

        *)
        echo "ERROR: Unknown command '$1'" >&2
        return 1
        ;;
    esac
}

screensaver_suspend_loop()
{
  lockfile
  test "${TMPDIR+set}" = set || TMPDIR=/tmp
  tmpfile=`mktemp $TMPDIR/tmp.XXXXXXXXXX`
  # Filter stale entries from the xdg-screensaver status file
  cat "$screensaver_file" 2> /dev/null | (
    IFS_save="$IFS"
    IFS=":"
    while read wid pid; do
      if ps -p "$pid" 2> /dev/null | grep xprop > /dev/null; then
        echo "$wid:$pid"
      fi
    done
    IFS="$IFS_save"
  ) > $tmpfile
  if [ -s "$tmpfile" ] ; then
    # Suspend pending, don't do a thing
    $MV "$tmpfile" "$screensaver_file"
    unlockfile
    return
  fi
  $MV "$tmpfile" "$screensaver_file"
  unlockfile
  (while [ -f "$screensaver_file" ]; do $*; sleep 50; done) > /dev/null 2> /dev/null &
}

screensaver_dbus_process ()
{
  perl -e '
use strict;
use warnings;
use Encode qw(decode);
use IO::File;
use Net::DBus;
use X11::Protocol;

my ($window_id, $screensaver_file, $dbus_service, $dbus_path) = @ARGV;

# Find window name to pass to session manager.
my $x = X11::Protocol->new();
my $named_window_id = hex($window_id);
my $window_name;
while (1) {
  ($window_name) = $x->GetProperty($named_window_id, $x->atom("WM_NAME"),
				   $x->atom("STRING"), 0, 1000, 0);
  last if defined($window_name) && $window_name ne "";
  (undef, $named_window_id) = $x->QueryTree($named_window_id);
  if (!defined($named_window_id)) {
    $window_name = "?";
    last;
  }
}

# Replace any invalid unicode characters with U+FFFD, so we dont crash when we
# pass them over to D-Bus
$window_name = decode("utf8", $window_name, Encode::FB_DEFAULT);

# Inhibit idle detection (flags = 8) with window name and ID.
# We have no reason so just send the window name again.
my $bus = Net::DBus->session();
my $sm_svc = $bus->get_service($dbus_service);
my $sm = $sm_svc->get_object($dbus_path, $dbus_service);
$sm->Inhibit($window_name, hex($window_id), $window_name, 8);

# Wait until removed from the status file.
while (1) {
  sleep(10);
  my $status = new IO::File($screensaver_file, "r")
    or exit 0;
  my $found;
  while (<$status>) {
    if (/^$window_id:/) {
      $found = 1;
      last;
    }
  }
  exit 0 unless $found;
}
' "$1" "$2" "$3" "$4" &
  }

screensaver_gnome_screensaver()
{
# DBUS interface for gnome-screensaver
# http://people.gnome.org/~mccann/gnome-screensaver/docs/gnome-screensaver.html
    case "$1" in
        suspend)
        screensaver_dbus_process $window_id $screensaver_file "org.gnome.SessionManager" "/org/gnome/SessionManager"
        result=0
        ;;

        resume)
        # Automatic resume when $screensaver_file disappears
        result=0
        ;;

        activate)
        dbus-send --session \
                  --dest=org.gnome.ScreenSaver \
                  --type=method_call \
                  /org/gnome/ScreenSaver \
                  org.gnome.ScreenSaver.SetActive \
                  boolean:true \
                  2> /dev/null
        result=$?
        ;;

        lock)
        dbus-send --session \
                  --dest=org.gnome.ScreenSaver \
                  --type=method_call \
                  /org/gnome/ScreenSaver \
                  org.gnome.ScreenSaver.Lock \
                  2> /dev/null
        result=$?
        ;;

        reset)
        # Turns the screensaver off right now
        dbus-send --session \
                  --dest=org.gnome.ScreenSaver \
                  --type=method_call \
                  /org/gnome/ScreenSaver \
                  org.gnome.ScreenSaver.SimulateUserActivity \
                 2> /dev/null
        result=$?
        ;;

        status)
        status=`dbus-send --session \
                          --dest=org.gnome.ScreenSaver \
                          --type=method_call \
                          --print-reply \
                          --reply-timeout=2000 \
                          /org/gnome/ScreenSaver \
                          org.gnome.ScreenSaver.GetActive \
                          | grep boolean | cut -d ' ' -f 5`
        result=$?
        if [ x"$status" = "xtrue" ] || [ x"$status" = "xfalse" ]; then
            echo "enabled"
        elif [ x"$result" != "x0" ]; then
            echo "ERROR: dbus org.gnome.ScreenSaver.GetActive returned '$status'" >&2
            return 1
        else
            echo "disabled"
        fi
        ;;

        *)
        echo "ERROR: Unknown command '$1" >&2
        return 1
        ;;
    esac
}

screensaver_mate_screensaver()
{
# DBUS interface for mate-screensaver
# This is same as gnome's for now but may change in the future as MATE
# does not follow gnome's development necessarily.
    case "$1" in
        suspend)
        screensaver_suspend_loop \
        dbus-send --session \
                  --dest=org.mate.ScreenSaver \
                  --type=method_call \
                  /org/mate/ScreenSaver \
                  org.mate.ScreenSaver.SimulateUserActivity \
                  2> /dev/null
        result=$?
        ;;

        resume)
        # Automatic resume when $screensaver_file disappears
        result=0
        ;;

        activate)
        dbus-send --session \
                  --dest=org.mate.ScreenSaver \
                  --type=method_call \
                  /org/mate/ScreenSaver \
                  org.mate.ScreenSaver.SetActive \
                  boolean:true \
                  2> /dev/null
        result=$?
        ;;

        lock)
        mate-screensaver-command --lock > /dev/null 2> /dev/null
        result=$?
        ;;

        reset)
        # Turns the screensaver off right now
        dbus-send --session \
                  --dest=org.mate.ScreenSaver \
                  --type=method_call \
                  /org/mate/ScreenSaver \
                  org.mate.ScreenSaver.SimulateUserActivity \
                 2> /dev/null
        result=$?
        ;;

        status)
        status=`dbus-send --session \
                          --dest=org.mate.ScreenSaver \
                          --type=method_call \
                          --print-reply \
                          --reply-timeout=2000 \
                          /org/mate/ScreenSaver \
                          org.mate.ScreenSaver.GetActive \
                          | grep boolean | cut -d ' ' -f 5`
        result=$?
        if [ x"$status" = "xtrue" ] || [ x"$status" = "xfalse" ]; then
            echo "enabled"
        elif [ x"$result" != "x0" ]; then
            echo "ERROR: dbus org.mate.ScreenSaver.GetActive returned '$status'" >&2
            return 1
        else
            echo "disabled"
        fi
        ;;

        *)
        echo "ERROR: Unknown command '$1" >&2
        return 1
        ;;
    esac
}

screensaver_cinnamon_screensaver()
{
# DBUS interface for cinnamon-screensaver
# https://raw.githubusercontent.com/linuxmint/cinnamon-screensaver/master/doc/dbus-interface.html
    case "$1" in
        suspend)
        screensaver_suspend_loop \
        dbus-send --session \
                  --dest=org.cinnamon.ScreenSaver \
                  --type=method_call \
                  /org/cinnamon/ScreenSaver \
                  org.cinnamon.ScreenSaver.SimulateUserActivity \
                  2> /dev/null
        result=$?
        ;;

        resume)
        # Automatic resume when $screensaver_file disappears
        result=0
        ;;

        activate)
        dbus-send --session \
                  --dest=org.cinnamon.ScreenSaver \
                  --type=method_call \
                  /org/cinnamon/ScreenSaver \
                  org.cinnamon.ScreenSaver.SetActive \
                  boolean:true \
                  2> /dev/null
        result=$?
        ;;

        lock)
        dbus-send --session \
                  --dest=org.cinnamon.ScreenSaver \
                  --type=method_call \
                  /org/cinnamon/ScreenSaver \
                  org.cinnamon.ScreenSaver.Lock \
                  string:"" \
                  2> /dev/null

        result=$?
        ;;

        reset)
        # Turns the screensaver off right now
        dbus-send --session \
                  --dest=org.cinnamon.ScreenSaver \
                  --type=method_call \
                  /org/cinnamon/ScreenSaver \
                  org.cinnamon.ScreenSaver.SimulateUserActivity \
                 2> /dev/null
        result=$?
        ;;

        status)
        status=`dbus-send --session \
                          --dest=org.cinnamon.ScreenSaver \
                          --type=method_call \
                          --print-reply \
                          --reply-timeout=2000 \
                          /org/cinnamon/ScreenSaver \
                          org.cinnamon.ScreenSaver.GetActive \
                          | grep boolean | cut -d ' ' -f 5`
        result=$?
        if [ x"$status" = "xtrue" ]; then
            echo "enabled"
        elif [ x"$status" = "xfalse" ]; then
            echo "disabled"
        else
            echo "ERROR: dbus org.cinnamon.ScreenSaver.GetActive returned '$status'" >&2
            return 1
        fi
        ;;

        *)
        echo "ERROR: Unknown command '$1" >&2
        return 1
        ;;
    esac
}

screensaver_xscreensaver()
{
    case "$1" in
        suspend)
        screensaver_suspend_loop xscreensaver-command -deactivate
        result=0
        ;;

        resume)
        # Automatic resume when $screensaver_file disappears
        result=0
        ;;

        activate)
        xscreensaver-command -activate > /dev/null 2> /dev/null
        result=$?
        ;;

        lock)
        xscreensaver-command -lock > /dev/null 2> /dev/null
        result=$?
        ;;

        reset)
        # Turns the screensaver off right now
        xscreensaver-command -deactivate > /dev/null 2> /dev/null
        result=$?
        ;;

        status)
        result=0
        if [ -f "$screensaver_file" ] ; then
            echo "disabled"
        else
            echo "enabled"
        fi
        ;;

        *)
        echo "ERROR: Unknown command '$1" >&2
        return 1
        ;;
    esac
}

xautolock_screensaver()
{
    case "$1" in
        suspend)
        xset s off && xautolock -disable > /dev/null
        result=$?
        ;;

        resume)
        xset s default && xautolock -enable > /dev/null
        result=$?
        ;;

        activate)
        xautolock -enable
        result=$?
        ;;

        lock)
        xautolock -locknow
        result=$?
        ;;

        reset)
        xautolock -restart
        result=$?
        ;;

        status)
        xautolock -unlocknow >/dev/null
        result=$?
        if [ $result -eq 0 ]; then
            echo "enabled"
        else
            echo "disabled"
        fi
        ;;

        *)
        echo "ERROR: Unknown command '$1" >&2
        return 1
        ;;
    esac
}

[ x"$1" != x"" ] || exit_failure_syntax

action=
window_id=

case $1 in
  suspend)
    action="$1"

    shift

    if [ -z "$1" ] ; then
        exit_failure_syntax "WindowID argument missing"
    fi

    window_id="$1"
    check_window_id
    ;;

  resume)
    action="$1"

    shift

    if [ -z "$1" ] ; then
        exit_failure_syntax "WindowID argument missing"
    fi

    window_id="$1"
    check_window_id
    ;;

  activate)
    action="$1"
    ;;

  lock)
    action="$1"
    ;;

  reset)
    action="$1"
    ;;

  status)
    action="$1"
    ;;

  *)
    exit_failure_syntax "unknown command '$1'"
    ;;
esac

detectDE
# Consider "xscreensaver" a separate DE
xscreensaver-command -version 2> /dev/null | grep XScreenSaver > /dev/null && DE="xscreensaver"
# Consider "gnome-screensaver" a separate DE
dbus-send --print-reply --dest=org.freedesktop.DBus /org/freedesktop/DBus org.freedesktop.DBus.GetNameOwner string:org.gnome.ScreenSaver > /dev/null 2>&1 && DE="gnome_screensaver"
# Consider "mate-screensaver" a separate DE
dbus-send --print-reply --dest=org.freedesktop.DBus /org/freedesktop/DBus org.freedesktop.DBus.GetNameOwner string:org.mate.ScreenSaver > /dev/null 2>&1 && DE="mate_screensaver"
# Consider "cinnamon-screensaver" a separate DE
dbus-send --print-reply --dest=org.freedesktop.DBus /org/freedesktop/DBus org.freedesktop.DBus.GetNameOwner string:org.cinnamon.ScreenSaver > /dev/null 2>&1 && DE="cinnamon"
# Consider "xautolock" a separate DE
xautolock -enable > /dev/null 2>&1 && DE="xautolock_screensaver"

if [ "$action" = "resume" ] ; then
    do_resume
    exit_success
fi

perform_action "$action"

if [ "$action" = "suspend" ] ; then
    # Start tracking $window_id and resume the screensaver once it disappears
    ( track_window  ) 2> /dev/null > /dev/null &
fi

if [ $result -eq 0 ]; then
    exit_success
else
    exit_failure_operation_failed
fi