#!/usr/bin/perl
# -*- Mode: cperl -*-
# Copyright (C) 2002 by Chmouel Boudjnah <chmouel@mandrakesoft.com>
# Redistribution of this file is permitted under the terms of the GNU
# Public License (GPL)
#
# Detect vga resolution we want.
#

#use strict;
my (%main, %entry);

my $vga = detect_from_cmdline(cat_('/proc/cmdline'));
undef $vga if $vga =~ /x/; #lilo cmdline can't convert

detect_from_loader() if not $vga;
if ($vga) {
    chomp $vga;
    $vga =~ s/vga=//;
    $vga = convert_vgamode();
}
print $vga, "\n" if $vga;

sub detect_from_cmdline {return (grep /vga=\d+/, split("[ \t]", shift))[0];}
sub detect_from_loader {
    my $loader = `detectloader -q`;chomp $loader;
    if ($loader =~ m/lilo/i ) {
	parse_lilo_conf();
	$vga = $entry{$main{default}}{vga};
	$vga = $main{vga} if not $vga;
    } elsif ($loader =~ /grub/i ) {
	parse_grub_conf();
	$vga = detect_from_cmdline($entry{$main{default}}{options});
    }
}
sub parse_grub_conf {
    my ($title);
    my $cnt = 0;
    my $grub_conf = "/boot/grub/menu.lst";
    return if not -f $grub_conf;
    open F, $grub_conf or die "Can't open $grub_conf\n";

    while (<F>) {
	next if /^\s*#/;
	$main{default} = $1 if /^default (\d+)/;
	if (/^title\s+(.*)/) {
	    $title=$1;
	    $entry{$title}{title} = $title;
	    $entry{$title}{cnt} = $cnt;
	    $main{default} = $title if $entry{$title}{cnt} eq $main{default};
	    $cnt++;
	}
	if (m/kernel\s+(\(.*\))([^\s]+)\s+(.*)/) {
	    $entry{$title}{partition} = $1;
	    $entry{$title}{kernel} = $2;
	    $entry{$title}{options} = $3;
	    $vga = $1 if /vga=(.*)/;
	    $entry{$title}{vga} = $vga if ($label and $vga);
	}
	$entry{$title}{initrd} = $1 if m/\s*initrd.*\)(.*)/;
    }
    close F;
}

sub parse_lilo_conf {
    my $lilo_conf="/etc/lilo.conf";
    my ($vga, $label);
    return if not -f $lilo_conf;
    open F, $lilo_conf or die "Can't open $lilo_conf\n";
    while (<F>) {
	next if /^\s*#/;
	$main{default} = $1 if m/^default=(.*)/;
	$main{vga} = $1 if m/^vga=(.*)/;
	$vga = $1 if /vga=(.*)/;
	$label=$1 if /label=(.*)/;
	$entry{$label}{vga} = $vga if ($label and $vga);
	undef $vga if (/image=/ and $vga);
    }
    close F;
}

sub convert_vgamode {
    my $v;
    #From drakx Xconfigurator_consts.pm
    my %vgamodes = (
		    '640xx8'       => [ '769', '0x301' ],
		    '640x480x8'    => [ '769', '0x301' ],
		    '800xx8'       => [ '771', '0x303' ],
		    '800x600x8'    => [ '771', '0x303' ],
		    '1024xx8'      => [ '773', '0x305' ],
		    '1024x768x8'   => [ '773', '0x305' ],
		    '1280xx8'      => [ '775', '0x307' ],
		    '1280x1024x8'  => [ '775', '0x307' ],
		    '1600xx8'      => [ '777', '0x309' ],
		    '1600x1200x8'  => [ '777', '0x309' ],
		    '640xx15'      => [ '784', '0x310' ],
		    '640x480x15'   => [ '784', '0x310' ],
		    '800xx15'      => [ '787', '0x313' ],
		    '800x600x15'   => [ '787', '0x313' ],
		    '1024xx15'     => [ '790', '0x316' ],
		    '1024x768x15'  => [ '790', '0x316' ],
		    '1280xx15'     => [ '793', '0x319' ],
		    '1280x1024x15' => [ '793', '0x319' ],
		    '1600xx15'     => [ '796', '0x31C' ],
		    '1600x1200x15' => [ '796', '0x31C' ],
		    '640xx16'      => [ '785', '0x311' ],
		    '640x480x16'   => [ '785', '0x311' ],
		    '800xx16'      => [ '788', '0x314' ],
		    '800x600x16'   => [ '788', '0x314' ],
		    '1024xx16'     => [ '791', '0x317' ],
		    '1024x768x16'  => [ '791', '0x317' ],
		    '1280xx16'     => [ '794', '0x31A' ],
		    '1280x1024x16' => [ '794', '0x31A' ],
		    '1600xx16'     => [ '797', '0x31D' ],
		    '1600x1200x16' => [ '797', '0x31D' ],
		    #-    '640xx24'      => 786, #- there is a problem with these resolutions since the BIOS may take 24 or 32 planes.
		    #-    '640x480x24'   => 786,
		    #-    '800xx24'      => 789,
		    #-    '800x600x24'   => 789,
		    #-    '1024xx24'     => 792,
		    #-    '1024x768x24'  => 792,
		    #-    '1280xx24'     => 795,
		    #-    '1280x1024x24' => 795,
		   );
    foreach my $k (keys %vgamodes) { $v = $k if grep { $_ eq $vga } @{$vgamodes{$k}} }
    undef $vga if not $v;return $v;
}
sub cat_ { local *F; open F, $_[0] or $_[1] ? die "cat of file $_[0] failed: $!\n" : return; my @l = <F>; wantarray ? @l : join '', @l }