#!/usr/bin/perl

use strict;
use warnings;

my (@objects, @sets, @unsorted_records, @headers, %have_header, $results);

foreach my $file (sort glob("./records*.dat")) {
    open(my $fh, '<', $file) or die "$file: $!\n";
    my @items = <$fh>;
    close($fh);
    push @sets, \@items;
}

my $i = 0;
foreach my $set (@sets) {
    foreach my $record (@$set) {
        next if $record =~ /^#/;
        chomp($record);
        my @ids = split m!\|!, $record;
        shift @ids;
        if (@ids > 3) {
            $have_header{$record}++;
            push @headers, $record if $have_header{$record} >= 2;
        }
        next unless @ids == 3;
        $objects[$i]->{$ids[0]}{$ids[1]} = $ids[2];
    }
    $i++;
}

for (my $i = 0; $i < @objects; $i++) {
    foreach my $record (keys %{$objects[$i]}) {
        foreach my $item (keys %{$objects[$i]->{$record}}) {
            $results->{$record}{$item} += $objects[$i]->{$record}{$item};
        }
    }
}

foreach my $record (keys %$results) {
    foreach my $item (sort { $a <=> $b } keys %{$results->{$record}}) {
        my $new_record = "|$record|$item|$results->{$record}{$item}";
        push @unsorted_records, $new_record;
    }
}

my @sorted_records = sort { (split m!\|!, $a)[2] <=> (split m!\|!, $b)[2] } @unsorted_records;

local $" = "\n";
print "@headers",        @headers        ? "\n" : '';
print "@sorted_records", @sorted_records ? "\n" : '';