#!/usr/bin/perl

# (c) 2002 Fonkie <fonkie@fsmat.at>
# License: GPL v2

use Unicode::String qw( utf16 );
use Getopt::Std;

use strict;
use vars qw( $c %opt );

my $file;
my $buff;

getopts("d",\%opt);

open IN,$ARGV[0];
while (read(IN, $buff, 8 * 2**10)) {
  $file.=$buff;
}
close IN;

my $attr = {
  song => {
    1 => "title",
    2 => "filename",
    3 => "album?",
    4 => "artist?",
    5 => "genre/eq?",
    6 => "filetype",
    8 => "creator"
  },
  list => {
    1 => "songlist",
    2 => "playlist"
  }
};

parse_section($file,"MAIN");

exit;

sub get_size {
  my $file=shift;

  my $hsize=substr($file,4,4);
  my $size=substr($file,8,4);

  $hsize=unpack "V",$hsize;
  $size=unpack "V",$size;

  $size=$hsize if($size<$hsize);

  return $size;
}

sub parse_section {
  my $file=shift;
  my $ohead=shift;

  my @f=();
  my $done;
  while(!$done) {
    my $size=get_size($file);
    push @f,substr($file,0,$size);
    $file=substr($file,$size);
    $done=1 if(length($file)<=0);
    $done=1 if($size<=0);
  }

  for(@f) {
    my $file=$_;

    my $head=substr($file,0,4);
    my $hsize=substr($file,4,4);
    my $size=substr($file,8,4);
    my $len=length($file);

    next unless($head =~ /^mh/);

    $hsize=unpack "V",$hsize;
    $size=unpack "V",$size;

    $size=$hsize if($size<$hsize);

    #print "got: $head [$hsize] [$size] [$len]\n";

    if($opt{d}) {
      $c++;
      my $n=sprintf "%.4d",$c;
      my $s=$hsize;
      $s=$size if($head eq "mhod");
      open OUT,">dump_$n";
      print OUT substr($file,0,$s);
      close OUT;
    }

    # do parsing

    if($head eq "mhbd") {
      print "got: main db element [$head] [$hsize] [$size] [$len]\n";
      my ($a1,$a2,$a3) = unpack "V4V4V4",substr($file,12,4);
      print "got: ????:  $a1\n";
      print "got: ????:  $a2\n";
      print "got: ????:  $a3\n";

    } elsif($head eq "mhsd") {
      print "got: main list element [$head] [$hsize] [$size] [$len]\n";
      my ($type) = unpack "V4",substr($file,12,4);
      my $t=$attr->{list}->{$type};
      print "got: type: $t [$type]\n";

    } elsif($head eq "mhlt") {
      print "got: list element [$head] [$hsize] [$size] [$len]\n";
      my ($count) = unpack "V4",substr($file,8,4);
      print "got: songs: $count\n";

    } elsif($head eq "mhlp") {
      print "got: playlist element [$head] [$hsize] [$size] [$len]\n";
      my ($count) = unpack "V4",substr($file,8,4);
      print "got: playlists: $count\n";

    } elsif($head eq "mhit") {
      print "got: song item element [$head] [$hsize] [$size] [$len]\n";
      my ($count,$ind,$a3,$a4,$type,$date,$size,$dur,$order,
          $a10,$a11,$a12,$a13)=
        unpack "V4V4V4V4V4V4V4V4V4V4V4V4V4",substr($file,12,72);
      print "got: $count attribute elements\n";
      print "got: index: $ind\n";
      print "got: ????:  $a3\n";
      print "got: ????:  $a4\n";
      print "got: type:  $type\n";
      my $date_o=$date;
      $date=$date-2082844800;
      my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) =
        localtime($date);
      $year+=1900;
      $mon+=1;
      my $d=sprintf "%.4d/%.2d/%.2d %.2d:%.2d:%.2d",$year,$mon,$mday,$hour,$min,$sec;
      print "got: date:  $d [$date_o]\n";
      print "got: size:  $size\n";
      my $h=int(($dur/1000)/60/60);
      my $m=int(($dur/1000)/60)-60*$h;
      my $s=int(($dur/1000))-60*$m;
      my $r=substr($dur,length($dur)-3);
      my $d=sprintf "%.2d:%.2d:%.2d.%s",$h,$m,$s,$r;
      print "got: dur:   $d [$dur]\n";
      print "got: order: $order\n";
      print "got: ????:  $a10\n";
      print "got: ????:  $a11\n";
      print "got: ????:  $a12\n";
      print "got: ????:  $a13\n";

    } elsif($head eq "mhod") {
      print "got: attribute element [$head] [$hsize] [$size] [$len]\n";
      my ($type,$a2,$a3,$a4,$size)=
        unpack "V4V4V4V4V4",substr($file,12,20);
      my $t="special";
      $t=$attr->{song}->{$type} if($ohead eq "mhit");
      print "got: type: $t [$type]\n"; 
      if($type == 100) {
        print "got: not a string element\n";
        print "got: ????: $a2\n";
        print "got: ????: $a3\n";
        print "got: ????: $a4\n";
        print "got: size: $size (?)\n";
      } else {
        print "got: ????: $a4\n"; 
        my $gs=$size-40;
        $gs=0 if($gs<0);
        my $s=substr($file,40,$size);
        my $u=utf16($s);
        $u->byteswap;
        my $ustr=$u->latin1;
        my $l=length $ustr;
        print "got: size: $l [$size]\n"; 
        print "got: ustr: $ustr\n" if $ustr;
      }

    } elsif($head eq "mhyp") {
      print "got: playlist info [$head] [$hsize] [$size] [$len]\n";
      my ($attr,$count,$a3,$a4,$a5,$a6,$a7,$a8,$a9,
          $a10,$a11,$a12,$a13)=
        unpack "V4V4V4V4V4V4V4V4V4V4V4V4V4",substr($file,12,72);
      print "got: attributes:  $attr\n";
      print "got: songs:  $count\n";
      print "got: ????:  $a3\n";
      print "got: ????:  $a4\n";
      print "got: ????:  $a5\n";
      print "got: ????:  $a6\n";

    } elsif($head eq "mhip") {
      print "got: playlist item element [$head] [$hsize] [$size] [$len]\n";
      my ($a1,$a2,$a3,$ref,$a5,$a6,$a7,$a8,$a9,
          $a10,$a11,$a12,$a13)=
        unpack "V4V4V4V4V4V4V4V4V4V4V4V4V4",substr($file,12,72);
      print "got: ????:  $a1\n";
      print "got: ????:  $a2\n";
      print "got: ????:  $a3\n";
      print "got: reference:  $ref\n";
      print "got: ????:  $a5\n";
 
    } else {
      print "error: unknown header: $head\n";
    }

    print "\n";

    # recursion

    my $f=substr($file,$hsize,$size-$hsize);
    parse_section($f,$head);
  }
}