#!/usr/bin/perl

use strict;

our $mergebinhigh;
our $mergebinlow;
our $mergelength=0;
our $headerlength = 55;

use Getopt::Long;
our ($filename, $startnum, $endnum, $outputhigh, $outputlow, $uebertraghigh, $uebertraglow, $delete);



GetOptions('filename=s' => \$filename, 'startnum=s' => \$startnum, 'endnum=s' => \$endnum,
'outputhigh=s' => \$outputhigh, 'outputlow=s' => \$outputlow, 'uebertraghigh=s' => \$uebertraghigh, 'uebertraglow=s' => \$uebertraglow, 'delete=s' => \$delete) or die("Error in command line arguments\n");;



if (-e $uebertraghigh)
{
	addimage($uebertraghigh, 'high');
	unlink($uebertraghigh) if ($delete);
}

if (-e $uebertraglow)
{
	addimage($uebertraglow, 'low');
	unlink($uebertraglow) if ($delete);
}

for (my $num = $startnum; $num <= $endnum; $num++)
{
	my $filenumname = $filename;
	$filenumname=~s/%NUM%/$num/gi;
	if (-e $filenumname)
	{
		if (($outputhigh) && ($outputlow))
		{
			addimage($filenumname);
		}
		elsif ($outputhigh)
		{
			addimage($filenumname,'high');
		}
		elsif ($outputlow)
		{
			addimage($filenumname,'low');
		}
		unlink($filenumname) if ($delete);
	}
	else
	{
		print "merging: $filenumname file not found!!!\n";
	}
}

#### output file
if ($outputhigh)
{
open (FILE, '>:raw',$outputhigh) || die ("canot open $outputhigh because of $!");
binmode (FILE);
print FILE $mergebinhigh;
close (FILE);
print "[$$] merging finished $filename $startnum .. $endnum to  $outputhigh\n";
}

if ($outputlow)
{
open (FILE, '>:raw',$outputlow) || die ("canot open $outputhigh because of $!");
binmode (FILE);
print FILE $mergebinlow;
close (FILE);
print "[$$] merging finished $filename $startnum .. $endnum to  $outputhigh\n";
}

#print "\n" .  `ps $$` . "\n";
exit;



sub addimage
{
my ($filename, $modus) = @_;
open (FILE, '<:raw',$filename) || die ("canot open $_[0] because of $!");
binmode (FILE);
read FILE, my $content, 100000000;
close (FILE);
#print "datei $_[0] gelesene bytes: " . length($content) . "\n";


if ($mergelength eq 0)
{
	$mergelength = length($content);
	$mergebinhigh = $content;
	$mergebinlow = $content;
	#print "first image $filename loaded.\n";
	return;
}
if ($mergelength ne length($content))
{
	print "file length of $filename not matches others! skipping.\n";
	return;
}

#print "merging $filename ...\n";
my ($a, $b);
my $mergeddata;
if ($modus ne 'low')
{
   $mergeddata = substr($mergebinhigh,0,$headerlength);

	for (my $i = $headerlength; $i<=$mergelength;$i++)
	{
		$a = substr($mergebinhigh,$i,1);
		$b = substr($content,$i,1);

		if ($a ge $b)
		{
			$mergeddata .= $a;
		}
		else
		{
			$mergeddata .= $b;
		}
	}
$mergebinhigh = $mergeddata;
}

if ($modus ne 'high')
{
$mergeddata = substr($mergebinlow,0,$headerlength);
	for (my $i = $headerlength; $i<=$mergelength;$i++)
	{
		$a = substr($mergebinlow,$i,1);
		$b = substr($content,$i,1);

		if ($a lt $b)
		{
			$mergeddata .= $a;
		}
		else
		{
			$mergeddata .= $b;
		}
	}
$mergebinlow = $mergeddata;
}

return;
}