#!/usr/bin/perl
# -*- Mode: cperl -*-
# Copyright (C) 2000 by Chmouel Boudjnah <chmouel@mandrakesoft.com>,
# MandrakeSoft Inc.
# Redistribution of this file is permitted under the terms of the GNU 
# Public License (GPL)
# $Id$
######################
# Description: Launch window manager according to
# /etc/X11/window-manager with various options.

use Getopt::Long;

my ($wm, $command, $window_mgr_file);
my (@lf);

my @getopt_args = ('l|list-active-session', 
		   'i|xinit',
		   'a|alias',
		   'm|window-manager-file=s',
		   'g|with-file-manager=s',
		   'p|picture=s',
		   'x|with-xterm',
		   'h|help',
		   'F|fallback',
		  );
GetOptions(\%options, @getopt_args) ||  usage(1);
usage() if $options{h};

$window_mgr_file = $options{'m'} ? $options{'m'} : '/etc/X11/window-managers';
die "$window_mgr_file don't exist\n" unless -r $window_mgr_file;
parse_file($window_mgr_file);

if ($options{l}){
    print "\t\t\tActive Sessions:\n";
    list_sessions();
    exit(0);
}

if ($options{a}) {print "alias $_=\'$0 -i $_\';" for @lf; exit 0;}

unless ($ARGV[0]) { 
    print STDERR  "\n\t\tYou need to specify a Window Manager\n\n"; 
    usage(1);
} else { $wm  = $ARGV[0] }


if (!$exec{$wm} && !$options{F}) {
    print STDERR "I can't find an entry for $wm\n";
    print STDERR "This is the list of active sessions:\n\n";
    list_sessions(1);
    print STDERR "\nVerify your installation or adjust $window_mgr_file\n";
    exit 1;
}

# Launching
if ($options{p} and $options{b}) {
    print STDERR "option -p and -b are incompatible\n";
    exit 1;
} else {
    system("xsetroot", "-solid", $options{b}) if $options{b};
}

if ($options{g} =~ /KFM/i) {
    system("kfm &");
} elsif ($options{g} =~ /GMC/i) {
    system("gmc &");
} elsif ($options{g} =~ /SFM/i) { #Special Pixel.
    system("sfm &");
} else {
    if ($options{g}) {
	print STDERR "You need to specify KFM or GMC to --with-filemanager";
	exit(1);
    }
}

if ( $options{p} and ! -x '/usr/X11R6/bin/xsetbg') {
    print STDERR "Can't find xli installed, please adjust your installation\n";
    exit(1);
} else { system("xsetbg", $options{p}) if $options{p}; }
if ($options{x}) {
    my $xterm = $ENV{XTERM} ? $ENV{XTERM} : "xterm -bg black -fg white";
    system("$xterm &");
}

# END
if (!$options{i}) {
    $command = $script{$wm} ? $script{$wm} : $script{shift @lf}; 
    exec ("/bin/sh", "-c", "$command");
} else {
    exec ("xinit $exec{$wm}");
}

sub parse_file {
  my $f=shift @_;
  local *F;
  my ($e, $s, $n, $i, $d);
  open F, $f or die "Can't open $f\n";
  local $/ = "--@@--";
  while (<F>) {
     $n = $1 if /^NAME=(.*)/m;
     $e = $1 if /^EXEC=(.*)/m;
     $d = $1 if /^DESC=(.*)/m;
     $i = $1 if /^ICON=(.*)/m;
     $s = $1 while /SCRIPT:(.*?)$/gs;
     if (-x $e) { $script{$n} = $s; $exec{$n} = $e; push @lf, $n; }
  }
}

sub list_sessions{my $e=shift @_;for(@lf){print{$e ? STDERR : STDOUT}"$_\n";}}

sub usage {
  my $e = shift @_;
  (my $basename = $0) =~ s|.*/||;
  print {  $e ? STDERR : STDOUT } << "EOF";
Usage: $0 [-Faixh] [ -b color ] [ window-manager session]
Window-Manager launcher

  -i			--xinit:   Launch with xinit.
  -a			--alias:   Product alias for bourne shell.
  -b=COLOR   --background=COLOR:   Specify a background color.
  -g        --with-file-manager:   Launch with a filemanager [ KFM | GMC ]
  -x		  --with-xtermM:   Display an xterm.
  -p=PIC          --picture=PIC:   Pictures to display in background.
  -l      --list-active-session:   List active sessions.
  -F 	             --fallback:   Try to fallback between window-managers
				   if failing to launch the specified one.
  -h			 --help:   Display this message.

EOF
  exit($e);
}