#!/usr/bin/perl -w
use strict;
use Compress::Zlib;
use IO::File;
use Getopt::Long;
sub usage {
    "Usage: uncomp [-o OFFS] [-w WINDOW] [-l COMPLEVEL] [-b BUFSZE] {-d|-c} file\n"
   ."     -T   : trace on byte level\n"
}
my $offset=0;
my $decompress=1;
my $compress;
my $windowbits;
my $level;
my $bufsize;
my $trace;
my $gzip;
GetOptions(
    "o=s" => sub { $offset=eval($_[1]); },
    "d" => sub { $decompress=1; $compress=0; },
    "c" => sub { $compress=1; $decompress=0; },
    "w=s" => sub { $windowbits=eval($_[1]); },
    "l=s" => sub { $level=eval($_[1]); },
    "b=s" => sub { $bufsize=eval($_[1]); },
    "g" => \$gzip,
    "T" => \$trace,
) || die usage();
my $fn=shift || die usage();
my $fh=$fn eq '-' ? *STDIN : IO::File->new($fn, "r") or die "$fn: $!\n";
binmode $fh;
my $data;
if ($fn eq '-') {
    local $/;
    $data=<>;
}
else {
    $fh->seek($offset, SEEK_SET);
    $fh->read($data, (-s $fh) - $offset);
}
$fh->close();
my $datalen= length($data);
binmode STDOUT;
my @options;
push @options, (-WindowBits=>$windowbits) if defined $windowbits;
push @options, (-Level=>$level) if defined $level;
push @options, (-Bufsize=>$bufsize) if defined $bufsize;
if ($gzip) {
    if ($decompress) {
        my $output= Compress::Zlib::memGunzip($data);
        warn sprintf("left: 0x%x bytes\n", length($data));
        print $output;
    }
    elsif ($compress) {
    }
}
elsif ($trace) {
    if ($decompress) {
	my $d= inflateInit(@options);
        tracedecompress($offset, $d, $data);
    }
    elsif ($compress) {
	my $d= deflateInit(@options);
        tracecompress($offset, $d, $data);
    }
}
elsif ($decompress) {
	#print Compress::Zlib::uncompress($data);
	my $d= inflateInit(@options);

	my ($output, $err)= $d->inflate($data);
	if ($err!=Z_STREAM_END) {
		warn sprintf("left: 0x%x bytes, offset 0x%x - error: %s\n", length($data), $datalen-length($data)+$offset, $err)
	}
	print $output;
	if (length($data)) {
		warn sprintf("left: 0x%x bytes, offset 0x%x\n", length($data), $datalen-length($data)+$offset);
	}
}
elsif ($compress) {
	#print Compress::Zlib::compress($data);
	my $d= deflateInit(@options);
	my ($output, $err)= $d->deflate($data);
	print $output;
	($output, $err)= $d->flush();
	print $output;
}

sub tracedecompress {
    my $baseofs= shift;
    my $d= shift;
    my $oofs= 0;
    for (my $ofs= 0 ; $ofs<length($data) ; $ofs++)
    {
        my $compbyte= substr($_[0], $ofs, 1);
        my ($output, $err)= $d->inflate($compbyte);
        printf("%08lx %s -> [%4d] %08lx: %s\n",
            $baseofs+$ofs, unpack("H*", substr($_[0], $ofs, 1)),
            $err,
            $oofs, unpack("H*", $output));
        $oofs += length($output);
    }
}
sub tracecompress {
    my $baseofs= shift;
    my $d= shift;
    my $oofs= 0;
    for (my $ofs= 0 ; $ofs<length($data) ; $ofs++)
    {
        my $compbyte= substr($_[0], $ofs, 1);
        my ($output, $err)= $d->deflate($compbyte);
        printf("%08lx %s -> [%4d] %08lx: %s\n",
            $baseofs+$ofs, unpack("H*", substr($_[0], $ofs, 1)),
            $err,
            $oofs, unpack("H*", $output));
        $oofs += length($output);
    }
}