#!/usr/bin/env perl -l

use strict;
use warnings;
use autodie;

for (@ARGV) {
    my ($input_file, $output_file) = ($_, $_ . '__OUTPUT.txt');
    my (%reformat, @order);

    read_input($input_file, \%reformat, \@order);
    write_output($output_file, \%reformat, \@order);
}

{
    my $re; INIT { $re = qr{^(H\d+,\d+,)(.*)$} }

    sub read_input {
        my ($input_file, $reformat, $order) = @_;

        open my $in_fh, '<', $input_file;

        while (<$in_fh>) {
            next if $. == 1;
            chomp;
            /$re/;
            my ($key, $str_part) = ($1, $2);
            push @$order, $key unless exists $reformat->{$key};
            push @{ $reformat->{$key} }, $str_part;
        }

        return;
    }
}

sub write_output {
    my ($output_file, $reformat, $order) = @_;

    open my $out_fh, '>', $output_file;

    print $out_fh $_, join ' ', @{ $reformat->{$_} } for @$order;

    return;
}