#!/usr/bin/perl

use v5.36;
use strict;
use utf8;

=head1 NAME

hedgedoc2quarto - convert HedgeDoc content to Quarto

=head1 VERSION

Version 0.0.1

=head1 SYNOPSIS

    hedgedoc2quarto INFILE OUTFILE

    hedgedoc2quarto < INFILE > OUTFILE

=head1 DESCRIPTION

B<hedgedoc2quarto> reformats text content
from HedgeDoc- to Quarto-flavored Markdown,
and adapt Mermaid diagram code.

Both HedgeDoc and Quarto use Markdown,
but different flavors,
and they support different subsets of Mermaid diagram code.

=cut

# slurp INFILE if passed as first argument, or else STDIN
my ( $infile, $outfile, $bogus ) = @ARGV;
die 'Too many arguments: expected INFILE and OUTFILE' if $bogus;
@ARGV = ($infile) if $infile;
my $content = do { local $/ = undef; <> };

$content
	=~ s/^(?'fence'[``~]{3,})\s*\Kmermaid\n(?'type'gantt)\n(?'code'.*?\n)\k'fence'$/
	"{mermaid}\n\%\%| fig-width: 100\%\n"
	. &mmd2mmd( $+{type}, $+{code} )
	. $+{fence}
	/gsme;

if ($outfile) {
	open( FH, '>', $outfile ) or die $!;
	print FH $content;
}
else {
	print $content;
}

sub mmd2mmd ( $type, $code )
{
	if ( $type eq 'gantt' ) {
		$code = "tickInterval 1month\n$code";
	}

	return "$type\n$code";
}

=encoding UTF-8

=head1 AUTHOR

Jonas Smedegaard C<< <dr@jones.dk> >>

=head1 COPYRIGHT AND LICENSE

  Copyright © 2024 Jonas Smedegaard

This program is free software:
you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License
as published by the Free Software Foundation,
either version 3, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY;
without even the implied warranty
of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU Affero General Public License for more details.

You should have received a copy
of the GNU Affero General Public License along with this program.
If not, see <https://www.gnu.org/licenses/>.

=cut

1;