<?php
/*
Plugin Name: wp-syntax
Plugin URI: http://www.mcgearygroup.com
Description: Syntax highlighting using <a href="http://qbnz.com/highlighter/">Geshi</a> supporting a wide range of popular languages.
Author: Ryan McGeary
Version: 0.2-dev
Author URI: http://www.mcgearygroup.com
*/

#
#  Copyright (c) 2007 Ryan McGeary
#
#  This file is part of WP-Syntax.
#
#  WP-Syntax 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 2 of the License, or (at your option)
#  any later version.
#
#  WP-Syntax 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 WP-Syntax; if not, write to the Free Software Foundation, Inc., 59
#  Temple Place, Suite 330, Boston, MA 02111-1307 USA
#

include_once("geshi/geshi.php");

function wp_syntax_code_trim($code)
{
    // special ltrim b/c leading whitespace matters on 1st line of content
    $code = preg_replace("/^\s*\n/siU", "", $code);
    $code = rtrim($code);
    return $code;
}

function wp_syntax_substitute(&$match)
{
    global $wp_syntax_token, $wp_syntax_matches;

    $i = count($wp_syntax_matches);
    $wp_syntax_matches[$i] = $match;

    return "\n\n<p>" . $wp_syntax_token . sprintf("%03d", $i) . "</p>\n\n";
}

function wp_syntax_highlight($match)
{
    global $wp_syntax_matches;

    $i = intval($match[1]);
    $match = $wp_syntax_matches[$i];

    $language = strtolower(trim($match[1]));
    $line = trim($match[2]);
    $code = wp_syntax_code_trim($match[3]);

    $geshi = new GeSHi($code, $language);

// count line breaks
// $lines = count(explode("\n", $code))

    return "\n<div class=\"wp_syntax_code\">\n"
        . $geshi->parse_code()
        . "\n</div>\n";
}

function wp_syntax_before_filter($content)
{
    return preg_replace_callback(
        "/\s*<pre(?:lang=\"([\w-]+)\"|line=\"(\d+)\"|\s)+>(.*)<\/pre>\s*/siU",
        "wp_syntax_substitute",
        $content
    );
}

function wp_syntax_after_filter($content)
{
    global $wp_syntax_token;

     $content = preg_replace_callback(
         "/<p>\s*".$wp_syntax_token."(\d{3})\s*<\/p>/si",
         "wp_syntax_highlight",
         $content
     );

    return $content;
}

$wp_syntax_token = md5(uniqid(rand()));

// We want to run before other filters; hence, a priority of 0 was chosen.
// The lower the number, the higher the priority.  10 is the default and
// several formatting filters run at or around 6.
add_filter('the_content', 'wp_syntax_before_filter', 0);
add_filter('the_excerpt', 'wp_syntax_before_filter', 0);
add_filter('comment_text', 'wp_syntax_before_filter', 0);

// We want to run after other filters; hence, a priority of 99.
add_filter('the_content', 'wp_syntax_after_filter', 99);
add_filter('the_excerpt', 'wp_syntax_after_filter', 99);
add_filter('comment_text', 'wp_syntax_after_filter', 99);

?>