#!/usr/bin/perl

$fidpath="./fids";
$mp3path="./mp3";

sub parse_playlist
{
	$prefix="$prefix  ";
	my $playlist_fid = shift;
	my $path = shift;

	print "$prefix [$path] ($playlist_fid)\n";
	mkdir $path;
	open(my $playlist, "<".$fidpath.'/'.$playlist_fid) or die "$playlist_fid: $!";
	binmode($playlist);
	while(my $status = read($playlist, $fid, 4))
	{
		#print "$prefix [debug] offset=".sprintf("%04x", tell($playlist))."\n";
		($decimal_fid) = unpack("l<*", $fid);
		$unpack_fid = sprintf("%x", $decimal_fid);
		#print "$prefix [debug] fid = $unpack_fid ($decimal_fid)\n";
		if ( ! $unpack_fid )
		{
			print "status:   $status\n";
			print "raw data: ".sprintf("%02x %02x %02x %02x", 
				$fid[0], $fid[1], $fid[2], $fid[3])."\n";
			print "offset:   ".tell($playlist)." (0x".sprintf("%04x", tell($playlist)).")\n";
			die "unable to parse fid $unpack_fid from $playlist_fid";
		}
		if ( $decimal_fid % 16 != 0 ) 
		{
			die "invalid fid: $unpack_fid"; # sanity check
		}
		$meta = substr($unpack_fid,0,-1)."1";
		#print "$prefix [debug] \$meta = $meta \$path='$path'\n";
		parse_meta($meta, $path);
	}
	close($playlist);
	$prefix=substr($prefix,0,-2);
}

sub parse_meta
{
	my $meta = shift;
	my $path = shift;

	open(META, "<".$fidpath.'/'.$meta) or do { warn "'$meta': $!"; sleep(10); return; };
	while($line = <META>)
	{
		chomp($line);
		if ( $line =~ m/(.*)=(.*)/ )
		{
			$info{$meta}{$1} = $2;
		}
	}
	close(META);

	$fid = substr($meta,0,-1)."0";
	if ( $info{$meta}{'type'} eq "playlist" )
	{
		parse_playlist($fid, $path . '/' . $info{$meta}{'title'});
	}
	elsif ( $info{$meta}{'type'} eq "tune" )
	{
		print "$prefix  - ".$info{$meta}{'title'}." ($fid)\n";
		link $fidpath.'/'.$fid, $path.'/'.$info{$meta}{'title'}.'.mp3';
	}
}

parse_playlist('100', $mp3path);