#!/usr/bin/perl -Tw

=for Description

    Use this program to transform ANSI markup text to HTML snippets.
    The input is drawn from STDIN and the output is printed to STDOUT.

    Usage:

        $: ansi_emitting_program.pl | ansi2html

    It was intended to create the POD snippets but the hex values
    are wrong which makes this program an undocumented TODO item.

=cut

use strict;
use warnings;
{
    use English qw( -no_match_vars $INPUT_RECORD_SEPARATOR );
}

my $Depth = 0;

my $compute_hex_rc = sub {
    my ($color) = @_;
    my ( $r, $g, $b, $n );
    $n = $color - 16;
    $r = int $n / 36;
    $n = $n - $r * 36;
    $g = int $n / 6;
    $n = $n - $g * 6;
    $b = $n;

    # FIXME
    my $hex = sprintf '%02X%02X%02X', $r * 36, $g * 6, $b;

    return $hex;
};

my $ansi2html_rc = sub {
    my ( $fg_bg, $color ) = @_;

    if ( !$fg_bg ) {

        my $html = '</span>' x $Depth;

        $Depth = 0;

        return "$html\n";
    }

    $Depth++;

    my $hex = $compute_hex_rc->($color);
    my $bg = $fg_bg == 38 ? "" : 'background-';

    return sprintf qq{<span style="%scolor:#%s">}, $bg, $hex;
};

my $entitize_rc = sub {
    my ($char) = @_;

    my $unicode = ord $char;

    return $char
        if $unicode < 128;

    return sprintf '&#%04d;', $unicode;
};

my $text = do { local $INPUT_RECORD_SEPARATOR = undef; <>; };

exit 0
    if !$text;

utf8::decode($text);

$text =~ s{ . \[ ( \d+ ) (?: ;5;( \d+ ) )? m }{ $ansi2html_rc->($1,$2) }xmseg;
$text =~ s{\n}{<br/>\n}xmsg;

$text = join '', map { $entitize_rc->($_) } split //, $text;

print $text;

__END__