#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

my %data;
my %hits;
my %used;

while(<DATA>) {
  next unless /^\s*\[([^\[\]]+)\]:\s*(.+?)\s*$/s;
  my $name=$1;
  my @param=split(/\s*,\s*/,$2);
  for(@param) {
    if(/\[([^\[\]]+)\]/) {
      push(@{$data{$name}},{type => 'node', value => '', name => $1});
      push(@{$hits{$name}},$1);
      $used{$1}++;
    }
    else {
      push(@{$data{$name}},{type => 'value', value => $_, name => ''});
    }
  }
}

print Dumper(\%hits);

printout(\%data);

my $do=1;
while($do) {
  $do=0;
  for my $k (sort keys(%hits)) {
    my $v=$hits{$k};
    my $prnt=0;
    for my $p (reverse 0..$#$v) {
      next if(exists($hits{$v->[$p]}));
      next if($used{$v->[$p]} > 1);

      my $kk=splice(@$v,$p,1);
      my $del=delete($data{$kk});
      delete($hits{$k}) unless(@$v);

      for my $pp (reverse 0..$#{$data{$k}}) {
        if($data{$k}->[$pp]->{name} eq $kk) {
          splice(@{$data{$k}},$pp,1,@$del);
        }
      }

      $do++;
      $prnt++;
    }

    if($prnt) {
      print "---------------------\n";
      printout(\%data);
    }
  }
}

print "---------------------\n";
printout(\%data);

sub printout {
  my ($data)=@_;
  for my $key (sort keys(%$data)) {
    my @vals;
    for(@{$data->{$key}}) {
      if($_->{type} eq 'node') {
        push(@vals,"[$_->{name}]");
      }
      else {
        push(@vals,$_->{value})
      }
    }
    print "[$key]:".join(", ",@vals)."\n";
  }
}

__DATA__
[1]: a, b
[2]: c, [1]
[3]: d, e
[4]: f, [3]
[5]: g, h
[6]: i, [5]
[7]: [2], [4]
[8]: j, [6]
[9]: [7], [8]