#!/usr/bin/perl
use strict;
use warnings;
use 5.010;
use Encode qw/decode encode FB_CROAK LEAVE_SRC/;

sub put {
    my ($count, $item) = @_;
    if ($count == 1) {
        say "1 $item";
    } else {
        say "$count ${item}s";
    }
}

my $line = "@ARGV";

my $unicode;
eval {
    $unicode = decode "UTF-8", $line, FB_CROAK | LEAVE_SRC;
};
# Not valid UTF-8
if ($@) {
    my $modifier = length($line) == 1 ? '' : 's';
    say length($line)." byte$modifier (UTF-8 not valid)";
} else {
    my @output;
    my @graphemes = $unicode =~ /\X/g;
    my @ucs2 = $unicode =~ /[\x{10000}-\x{10FFFF}]/g;
    my $ucs2chars = @ucs2 + length $unicode;
    if (@graphemes != length $unicode) {
        put scalar @graphemes, 'grapheme';
    }
    put length $unicode, 'codepoint';
    if ($ucs2chars != length $unicode) {
        put $ucs2chars, 'Java character';
    }
    if (length $unicode != length $line) {
        put length $line, 'UTF-8 byte';
    }
}