# Copyright (C) 2004  Alex Schroeder <alex@emacswiki.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

use strict;
use v5.10;

AddModuleDescription('headers.pl', 'Header Markup Extension');

our ($q, $bol, %RuleOrder, @MyRules, $PortraitSupportColor, $PortraitSupportColorDiv);

# After toc.pl but before usemod.pl
push(@MyRules, \&HeadersRule);
$RuleOrder{\&HeadersRule} = 95;

# The trickiest part is the first rule.  It finds titles like the following:
#
# foo
# ---
#
# This assumes that --- is not found at the beginning of a line.
# Normally this is used as an M-dash in the middle of text with no
# surrounding whitespace---like this.
#
# Similarly, the horizontal rule requires an empty preceding line to
# work.  We'll see how it goes.  ;)

sub HeadersRule {
  my $oldpos = pos;
  if ($bol && (m/\G((.+?)[ \t]*\n(---+|===+)[ \t]*\n)/cg)) {
    my $html = CloseHtmlEnvironments() . ($PortraitSupportColorDiv ? '</div>' : '');
    if (substr($3,0,1) eq '=') {
      $html .= $q->h2($2);
    } else {
      $html .= $q->h3($2);
    }
    $PortraitSupportColorDiv = 0;
    $PortraitSupportColor = 0;
    return $html . AddHtmlEnvironment('p');
  } elsif ($bol && m/\G(\s*\n)*----+[ \t]*\n?/cg) {
    my $html = CloseHtmlEnvironments() . ($PortraitSupportColorDiv ? '</div>' : '') . $q->hr();
    $PortraitSupportColorDiv = 0;
    $PortraitSupportColor = 0;
    return $html . AddHtmlEnvironment('p');
  }
  return;
}