#!/usr/bin/perl -w
# (C) 2004 F.Hauri - felix@f-hauri.ch
#
# Warning!!!
# This script in only a prototype!
# The goal of this script is to play with libGD.
#
#    DO NOT USE ON PUBLIC SERVER!!!
#
# There is lot of security holes!!!
#

use CGI qw(:standard :html3);
use CGI::Carp qw(fatalsToBrowser);
use GD;

my $query = new CGI;

my $imagesdir="/data/picturefiles";
my $Title="Titre de l'album";
my $bgcolor="#8AB6E7";
my $owidth=640;
my $oheight=480;
my $twidth=70;
my $theight=70;
my $nbr=60;

my @files;
my $back;
my $imgnr;

sub readparam {
    $imgnr=$1 if path_info() =~ /\/(\d+).jpg$/i;
    ($owidth,$oheight)=($1,$2) if path_info() =~ /\/(\d+)x(\d+)\//i;
    $back=$1 if path_info() =~ /\/(\#+[a-f0-9]{6})\//i;
}

sub listfiles {
    opendir DH,$imagesdir or die "Can't open dir \`\`$imagesdir''";
    @files=sort {
	(stat($imagesdir."/".$a))[9] <=> (stat($imagesdir."/".$b))[9]
 } grep {/.jpg$/i} readdir DH;
    closedir DH;
}

sub mpict {
    my $img1=GD::Image->newFromJpeg($imagesdir."/".$files[$imgnr]);
    my $img2=GD::Image->new($owidth,$oheight);
    my ($width,$height) = $img1->getBounds();
    my $rap;
    $rap=$oheight/$height if $height*$owidth/$oheight >=$width;
    $rap=$owidth/$width if $width > $height*$owidth/$oheight;
    my $neww=sprintf "%.0f", $width*$rap;
    my $newh=sprintf "%.0f", $height*$rap;
    my $hoff=sprintf "%.0f", ($owidth-$neww)/2;
    my $voff=sprintf "%.0f", ($oheight-$newh)/2;
    if (defined $back) {
	my ($red,$gre,$blu)=(0,0,0);
	($red,$gre,$blu)=(hex($1),hex($2),hex($3)) if $back =~
	    /^\#([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})$/i;

	my $color=$img2->colorAllocate($red,$gre,$blu);
	$img2->filledRectangle(0,0,$owidth,$oheight,$color);
    }
    $img2->copyResized($img1,$hoff,$voff,0,0,$neww,$newh,$width,$height);
    return $img2->jpeg(60);
}

sub imgindex {
    $_=$bgcolor;s/\#/\%23/;
    my ($urlcolor,$crt,@out)=($_,0);
    push @out, start_html({-bgcolor=>$bgcolor},$Title).h1($Title).
	start_form(-method=>"POST",-action=>script_name);
    $crt=param("crt") if param("crt");
    print STDERR "Crt: ".$crt."\n";
    $crt=$crt+$nbr if param("suivantes");
    $crt=$crt-$nbr if param("précédentes");
    $crt=$crt+$#files+1 if $crt < 0;
    $crt=$crt-$#files-1 if $crt > $#files;
    my $first=$crt-$nbr/2;
    $first=$first+$#files+1 if $first < 0;
    push @out, hidden(-name=>"crt",-value=>$crt,-override=>1).
	submit("précédentes").submit("suivantes").hr;
    for (1..$nbr) {
	push @out, do { $first != $crt
			    ?
			    a({-href=>script_name."?crt=".$first},
			      img({-border=>0,
				   -src=>script_name."/".$urlcolor."/".
				       $twidth."x".$theight."/".$first++.",jpg"}))
			    :
			    img({-border=>1,
				 -src=>script_name."/".$urlcolor."/".
				     $twidth."x".$theight."/".$first++.",jpg"});
		    };
	$first=0 if $first > $#files;

    }
    push @out, hr.img({-src=>script_name."/".$urlcolor."/".
			   $owidth."x".$oheight."/".$crt.",jpg"});
    push @out, end_form.end_html;
    return join "\n",@out;
}

listfiles();readparam();

if (defined $imgnr) {
    print header('image/jpeg').mpict;
} else {
    print header().imgindex();
}