#!/usr/bin/perl

# THIS CODE IS BUGGY AND SLOW

# It is only here as a "proof of concept"

# Download the real stuff at http://www.iguana.be/~stef/

# written by stef@iguana.be, June 2001
# based on the bommanews specs

# this is very SLOW!

# You will need to install Bit::Vector for this to work
# usage: $0 file.bn
# TODO: CLEANUP this mess


use Bit::Vector;
use FileHandle;
@chunk;
$v224 = Bit::Vector->new_Dec(328, 224);
$t = Bit::Vector->new(328);
$x = Bit::Vector->new(320);
for (0..223) {
   $bv[$_] = Bit::Vector->new_Dec(328, $_);
}

while (<>) {
	/^<<BPST\sFile=\[(.*)\]\sSize=(\d+)\s+!BPST>>$/ && do {
		$filename = $1;
		$size = $2;
				print "$filename $size\n";
		$file = new FileHandle ">$filename" or die;
		next;
	};
	$line = $_;
	$l = length($line);
	$lines++;
	if ($l % 41 != 1) {
		print "line lenght: ", length($line), " on line $lines\n";
		if ($l % 41 == 0) {
			print "prepending .\n";
			$line = "." . $line;
		}
	}
	@line = split('', $line);
	for $char (@line) {
		$ch = ord($char);
			if ($ch > 31) {
						unshift(@chunk, $ch - 32 );
			}
		if ($#chunk == 40)  {
			decode224(@chunk);
			$#chunk = -1;
		}
	}
	if ($#chunk != -1) {
		print "Line $lines, filling $#chunk .. 39\n";
		for ($#chunk .. 39) {
				unshift(@chunk, 0);
		}
		print "chunk now $#chunk\n";
		
		decode224(@chunk);
		$#chunk = -1;
	}
	

}
$file->truncate($size);
$file->close;

sub decode224 {
	$t->from_Dec(shift @_);
	for my $c (@_) {
		$t->Multiply($t, $v224);
		$carry = $t->add($t,
			 $bv[$c], 0);
	}
	$x->Interval_Copy($t,0,0,320);
	print $file $x->Block_Read();
}