#!/usr/bin/env perl

# http://www.perl.com/pub/2012/04/perlunicook-standard-preamble.html
use utf8;      # so literals and identifiers can be in UTF-8
use v5.12;     # or later to get "unicode_strings" feature
use strict;    # quote strings, declare variables
use warnings;  # on by default
use warnings  qw(FATAL utf8);    # fatalize encoding glitches
use open      qw(:std :utf8);    # undeclared streams in UTF-8
use charnames qw(:full :short);  # unneeded in v5.16

use Dancer;

use Encode ();
use HTML::Entities ();
use JSON::XS ();
use Devel::Peek;
use utf8;

our $string = "Hello – World";

get '/' => sub {
	return '<a href="/ok">ok</a> <a href="/crash">crash</a>';
};

get '/ok' => sub {
	my $perl_internal = Encode::decode('utf-8', $string);	# "use utf8;" above made $string be in utf-8, decode to Perl-internal (= Unicode, stored internally as utf-8, right?)
	HTML::Entities::decode_entities($perl_internal);	# in void context, expand entities in-place to Unicode
	my $json = JSON::XS::encode_json([$perl_internal]);	# pass a Perl data structure, and expect output to be a utf-8 encoded, binary string

	Dump( $perl_internal );
	Dump( $json );

	my $ok = utf8::decode($json);				# fairly good way to validate utf-8

	return "JSON:$json <br>". ($ok ? "ok" : "not ok");
};

get '/crash' => sub {
	my $perl_internal = Encode::decode('utf-8', $string);
	HTML::Entities::decode_entities($perl_internal);
	my $json = to_json([$perl_internal],{pretty => 0});	# JSON's to_json, in contrary to JSON::XS's to_json seems to do something wrong,

	Dump( $perl_internal );
	Dump( $json );
								# or is less clever in automagically handling what I'm doing wrong while preparing the scalar
	my $ok = utf8::decode($json);

	return "JSON:$json <br>". ($ok ? "ok" : "not ok");
};
 
dance;