#!/usr/bin/perl
#
# make_alt
# Generate alternate formats using NetPBM
#
# Hugo Haas, 4 July 2002
#
# $Id: make_alt 2259 2003-09-14 09:20:39Z hugo $

use strict;
use Image::Info qw(image_info dim);
use Getopt::Long;

my $thumb_suffix	= "-th";
my $thumb_height	= 128;
my $small_suffix	= "-sm";
my $small_size		= 640;
my $med_suffix		= "-med";
my $med_size		= 1024;

my $do_med = 0;
my $do_small = 0;
GetOptions('m' => \$do_med,
	   's' => \$do_small,
	   'a' => sub { $do_med = $do_small = 1; }
	   );

sub run() {
    my ($command)= (@_);
    print STDERR "Running: $command\n";
    my $ret = system($command);
    return($ret);
}

sub gen_alt() {
    my ($name, $suffix, $convopt, $size) = @_;

    my $dest = $name;
    $dest =~ s/(\.[^.]+)$/${suffix}$1/;
  scale:
    my $ret = &run("pnmscale $convopt $size $name.pnm > $dest.pnm");
    if ($ret != 0) {
	print STDERR "Error: rerunning command...\n"; 
	goto scale;
    }
    &run("pnmtojpeg --optimize $dest.pnm > $dest");
    unlink("$dest.pnm");
    &run("jhead -te $name $dest");
}

my $file;
foreach $file (@ARGV) {

    if ( ! -r $file ) {
        print STDERR "Can't read $file! skipping it...\n";
	next;
    }

    if ($file =~ m/${thumb_suffix}|${small_suffix}|${med_suffix}/) {
        print STDERR "Not master: skipping it...\n";
	next;
    }

    print STDERR "Processing $file:\n";

    # Prepare generation: convert to PNM
    &run("jpegtopnm $file > $file.pnm");

    # Generate thumbnail
    &gen_alt($file, $thumb_suffix, '-h', $thumb_height);

    # Generate alternate sizes
    my $info = image_info($file);
    my($w, $h) = dim($info);
    my $convopt;
    if ($w > $h) {
	$convopt = '-w';
    } else {
	$convopt = '-h';
    }
    &gen_alt($file, $small_suffix, $convopt, $small_size) if $do_small;
    &gen_alt($file, $med_suffix, $convopt, $med_size) if $do_med;

    # Remove temporary PNM file
    unlink("$file.pnm");
}