#!perl

HELP "help" => "The stuff you're looking at right now :)";

use List::Util qw(max);

sub command :Tab(help,wtf,omgwtfbbq) {
    my ($self, $cart, $command) = @_;

    return NEXT if $command !~ /^(?:help|wtf|omgwtfbbq)$/;

    say <<END;

1. Enter products, amounts or commands
2. Enter your name

You can press <Enter> after each element to get a follow-up prompt, or separate
individual elements with whitespace.

Valid commands:
END

    my $width = max(map length, keys %::HELP);
    say sprintf "  %-${width}s  %s", $_, $::HELP{$_} for sort keys %::HELP;

    return ACCEPT;
}