use Irssi;
use strict;
use FileHandle;

use vars qw($VERSION %IRSSI);
use POSIX;

$VERSION = "0.9.1+byte";
%IRSSI = (
    authors     => 'Andreas \'ads\' Scherbaum <ads@ufp.de>',
    name        => 'screen_away',
    description => 'set (un)away, if screen is attached/detached',
    license     => 'GPL v2',
    url         => 'none',
);

# screen_away irssi module
#
# written by Andreas 'ads' Scherbaum <ads@ufp.de>
#
# changes:
#  07.02.2004 fix error with away mode
#             thanks to Michael Schiansky for reporting and fixing this one
#
#
# usage:
#
# put this script into your autorun directory and/or load it with
#  /SCRIPT LOAD <name>
#
# there are 4 settings available:
#
# /set screen_away_active ON/OFF/TOGGLE
# /set screen_away_repeat <integer>
# /set screen_away_message <string>
# /set screen_away_window <string>
#
# active means, that you will be only set away/unaway, if this
#   flag is set, default is ON
# repeat is the number of seconds, after the script will check the
#   screen status again, default is 5 seconds
# message is the away message sent to the server, default: not here ...
# window is a window number or name, if set, the script will switch
#   to this window, if it sets you away, default is '1'
#
# normal you should be able to rename the script to something other
# than 'screen_away' (as example, if you dont like the name) by simple
# changing the 'name' parameter in the %IRSSI hash at the top of this script


# variables
my $timer_name = undef;
my $away_status = 0;

# Register formats
Irssi::theme_register(
[
 'screen_away_crap', 
 '{line_start}{hilight ' . $IRSSI{'name'} . ':} $0'
]);

# if we are running
my $screen_away_used = 0;

# try to find out, if we are running in a screen
# normal this would be:  irssi -(parent)-> shell -(parent)-> screen
# first get the parent pid of our parent
my $fh = new FileHandle;
if (!open($fh, "/proc/" . getppid() . "/status")) {
  # just return, we will never be called again
  Irssi::printformat(MSGLEVEL_CLIENTCRAP, 'screen_away_crap',
    "could not open status file for parent process (pid: " . getppid() . "): $!");
  return;
}
my @file = <$fh>;
close($fh);

# get parent pid
my $screen_pid = -1;
foreach (@file) {
  if ($_ =~ /^PPid:[\s\t]+(\d+).*/s) {
    $screen_pid = $1;
  }
}

if ($screen_pid == 1) {
    $screen_pid = getppid();
}

if ($screen_pid == -1) {
  Irssi::printformat(MSGLEVEL_CLIENTCRAP, 'screen_away_crap',
    "could not find parent pid from pid " . getppid());
  return;
}

# now open this parent and look for the name
$fh = new FileHandle;
if (!open($fh, "/proc/$screen_pid/status")) {
  Irssi::printformat(MSGLEVEL_CLIENTCRAP, 'screen_away_crap',
    "could not open status file for parent process (pid: $screen_pid): $!");
  return;
}
my @file = <$fh>;
close($fh);

# now check, if the name is 'screen'
if ($file[0] !~ /^Name:[\s\t]+screen/si) {
  Irssi::printformat(MSGLEVEL_CLIENTCRAP, 'screen_away_crap',
    "not running inside a screen");
  return;
}

my ($socket_name, $socket_path);

# search for socket
# normal we could search the socket file, ... if we know the path
# but so we have to call one time the screen executable
my $socket = `screen -ls`;
my $running_in_screen = 0;
# locale doesnt seems to be an problem (yet)
if ($socket !~ /^No Sockets found/s) {
  # ok, should have only one socket
  $socket_name = $socket;
  $socket_name =~ s/^[^\n]+\n[\s\t]($screen_pid\.[^\s\t]+).+$/$1/s;
  $socket_path = $socket;
  $socket_path =~ s/^.+\d+ Sockets? in ([^\n]+)\.\n.+$/$1/s;
  if (length($socket_path) != length($socket) and length($socket_path) != length($socket)) {
    # only activate, if both strings are changed
    $screen_away_used = 1;
  } else {
    Irssi::printformat(MSGLEVEL_CLIENTCRAP, 'screen_away_crap',
      "error reading screen informations from:");
    Irssi::printformat(MSGLEVEL_CLIENTCRAP, 'screen_away_crap',
      "$socket");
    return;
  }
}

# last check
if ($screen_away_used == 0) {
  return;
}

# build complete socket name
$socket = $socket_path . "/" . $socket_name;

# register config variables
Irssi::settings_add_bool('misc', $IRSSI{'name'} . '_active', 1);
Irssi::settings_add_int('misc', $IRSSI{'name'} . '_repeat', 5);
Irssi::settings_add_str('misc', $IRSSI{'name'} . '_message', "not here ...");
Irssi::settings_add_str('misc', $IRSSI{'name'} . '_window', "1");

# init process
screen_away();

# screen_away()
#
# check, set or reset the away status
#
# parameter:
#   none
# return:
#   0 (OK)
sub screen_away {
  my ($away, @screen, $screen);

  # only run, if activated
  if (Irssi::settings_get_bool($IRSSI{'name'} . '_active') == 1) {
    if ($away_status == 0) {
      # display init message at first time
      Irssi::printformat(MSGLEVEL_CLIENTCRAP, 'screen_away_crap',
        "activating $IRSSI{'name'} (interval: " . Irssi::settings_get_int($IRSSI{'name'} . '_repeat') . " seconds)");
    }
    # get actual screen status
    my @screen = stat($socket);
    # 00100 is the mode for "user has execute permissions", see stat.h
    if (($screen[2] & 00100) == 0) {
      # no execute permissions, Detached
      $away = 1;
    } else {
      # execute permissions, Attached
      $away = 2;
    }

    # check if status has changed
    if ($away == 1 and $away_status != 1) {
      # set away
      if (length(Irssi::settings_get_str($IRSSI{'name'} . '_window')) > 0) {
        # if length of window is greater then 0, make this window active
        Irssi::command('window goto ' . Irssi::settings_get_str($IRSSI{'name'} . '_window'));
      }
      Irssi::printformat(MSGLEVEL_CLIENTCRAP, 'screen_away_crap',
        "Set away");
      my $message = Irssi::settings_get_str($IRSSI{'name'} . '_message');
      if (length($message) == 0) {
        # we have to set a message or we wouldnt go away
        $message = "not here ...";
      }
	  my $utc = strftime "%c", localtime;
      $message =~ s/%TIME/$utc/;
		open(INFO, "/tmp/byte-irc");
		my $host = <INFO>;
		close(INFO);
      foreach (Irssi::servers()) {
        $_->command("AWAY -one $message") if (!$_->{usermode_away});
      }
      $away_status = $away;
    } elsif ($away == 2 and $away_status != 2) {
      # unset away
      Irssi::printformat(MSGLEVEL_CLIENTCRAP, 'screen_away_crap',
        "Reset away");
		open(INFO, "/tmp/byte-irc");
		my $host = <INFO>;
		close(INFO);
      foreach (Irssi::servers()) {
        $_->command('AWAY -one') if ($_->{usermode_away});
      }
      $away_status = $away;
    }
  }
  # but everytimes install a new timer
  register_screen_away_timer();
  return 0;
}

# register_screen_away_timer()
#
# remove old timer and install a new one
#
# parameter:
#   none
# return:
#   none
sub register_screen_away_timer {
  if (defined($timer_name)) {
    # remove old timer, if defined
    Irssi::timeout_remove($timer_name);
  }
  # add new timer with new timeout (maybe the timeout has been changed)
  $timer_name = Irssi::timeout_add(Irssi::settings_get_int($IRSSI{'name'} . '_repeat') * 1000, 'screen_away', '');
}