<?php
/*
Plugin Name: WP-Footnotes
Plugin URI: http://www.elvery.net/drzax/more-things/wordpress-footnotes-plugin/
Version: 4.2
Description: Allows a user to easily add footnotes to a post.
Author: Simon Elvery
Author URI: http://www.elvery.net/drzax/
*/

/*
 * This file is part of WP-Footnotes a plugin for Word Press
 * Copyright (C) 2007 Simon Elvery
 *
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

// Some important constants
define('WP_FOOTNOTES_OPEN', " ((");  //You can change this if you really have to, but I wouldn't recommend it.
define('WP_FOOTNOTES_CLOSE', "))");  //Same with this one.
define('WP_FOOTNOTES_VERSION', '4.2');

// Instantiate the class 
$swas_wp_footnotes = new swas_wp_footnotes();

// Encapsulate in a class
class swas_wp_footnotes {
	var $current_options;
	var $default_options;

	/**
	 * Constructor.
	 */
	function swas_wp_footnotes() {
		// Define the implemented option styles
		$this->styles = array(
			'decimal' => '1,2...10',
			'decimal-leading-zero' => '01, 02...10',
			'lower-alpha' => 'a,b...j',
			'upper-alpha' => 'A,B...J',
			'lower-roman' => 'i,ii...x',
			'upper-roman' => 'I,II...X', 
			'symbol' => 'Symbol'
		);

		// Define default options
		$this->default_options = array('superscript'=>true,
									  'pre_backlink'=>' [',
									  'backlink'=>'&#8617;',
									  'post_backlink'=>']',
									  'pre_identifier'=>'',
									  'list_style_type'=>'decimal',
									  'list_style_symbol'=>'&dagger;',
									  'post_identifier'=>'',
									  'pre_footnotes'=>'',
									  'post_footnotes'=>'',
									  'style_rules'=>'ol.footnotes{font-size:0.8em; color:#666666;}',
									  'no_display_home'=>false,
									  'no_display_archive'=>false,
									  'no_display_date'=>false,
									  'no_display_category'=>false,
									  'no_display_search'=>false,
									  'no_display_feed'=>false,
									  'combine_identical_notes'=>false,
									  'priority'=>11,
									  'version'=>WP_FOOTNOTES_VERSION);

		// Get the current settings or setup some defaults if needed
		if (!$this->current_options = get_option('swas_footnote_options')){
			$this->current_options = $this->default_options;
			update_option('swas_footnote_options', $this->current_options);
		} else {			
			// Set any unset options
			if ($this->current_options['version'] != WP_FOOTNOTES_VERSION) {
				foreach ($this->default_options as $key => $value) {
					if (!isset($this->current_options[$key])) {
						$this->current_options[$key] = $value;
					}
				}
				$this->current_options['version'] = WP_FOOTNOTES_VERSION;
				update_option('swas_footnote_options', $this->current_options);
			}
		}

/*		
		if (!empty($_POST['save_options'])){
			$footnotes_options['superscript'] = (array_key_exists('superscript', $_POST)) ? true : false;
			$footnotes_options['pre_backlink'] = $_POST['pre_backlink'];
			$footnotes_options['backlink'] = $_POST['backlink'];
			$footnotes_options['post_backlink'] = $_POST['post_backlink'];
			$footnotes_options['pre_identifier'] = $_POST['pre_identifier'];
			$footnotes_options['list_style_type'] = $_POST['list_style_type'];
			$footnotes_options['post_identifier'] = $_POST['post_identifier'];
			$footnotes_options['list_style_symbol'] = $_POST['list_style_symbol'];
			$footnotes_options['pre_footnotes'] = stripslashes($_POST['pre_footnotes']);
			$footnotes_options['post_footnotes'] = stripslashes($_POST['post_footnotes']);
			$footnotes_options['style_rules'] = stripslashes($_POST['style_rules']);
			$footnotes_options['no_display_home'] = (array_key_exists('no_display_home', $_POST)) ? true : false;
			$footnotes_options['no_display_archive'] = (array_key_exists('no_display_archive', $_POST)) ? true : false;
			$footnotes_options['no_display_date'] = (array_key_exists('no_display_date', $_POST)) ? true : false;
			$footnotes_options['no_display_category'] = (array_key_exists('no_display_category', $_POST)) ? true : false;
			$footnotes_options['no_display_search'] = (array_key_exists('no_display_search', $_POST)) ? true : false;
			$footnotes_options['no_display_feed'] = (array_key_exists('no_display_feed', $_POST)) ? true : false;
			$footnotes_options['combine_identical_notes'] = (array_key_exists('combine_identical_notes', $_POST)) ? true : false;
			$footnotes_options['priority'] = $_POST['priority'];
			update_option('swas_footnote_options', $footnotes_options);
		}elseif(!empty($_POST['reset_options'])){
			update_option('swas_footnote_options', '');
			update_option('swas_footnote_options', $this->default_options);
		}
*/

		// Hook me up
		add_action('the_content', array($this, 'process'), $this->current_options['priority']);
		add_action('admin_menu', array($this, 'add_options_page')); 		// Insert the Admin panel.
		add_action('wp_head', array($this, 'insert_styles'));
	}

	/**
	 * Searches the text and extracts footnotes. 
	 * Adds the identifier links and creats footnotes list.
	 * @param $data string The content of the post.
	 * @return string The new content with footnotes generated.
	 */
	function process($data) {
		global $post;

		// Check for and setup the starting number
		$start_number = (preg_match("|<!\-\-startnum=(\d+)\-\->|",$data,$start_number_array)==1) ? $start_number_array[1] : 1;

		// Regex extraction of all footnotes (or return if there are none)
		if (!preg_match_all("/(".preg_quote(WP_FOOTNOTES_OPEN)."|<footnote>)(.*)(".preg_quote(WP_FOOTNOTES_CLOSE)."|<\/footnote>)/Us", $data, $identifiers, PREG_SET_ORDER)) {
			return $data;
		}

		// Check whether we are displaying them or not
		$display = true;
		if ($this->current_options['no_display_home'] && is_home()) $display = false;
		if ($this->current_options['no_display_archive'] && is_archive()) $display = false;
		if ($this->current_options['no_display_date'] && is_date()) $display = false;
		if ($this->current_options['no_display_category'] && is_category()) $display = false;
		if ($this->current_options['no_display_search'] && is_search()) $display = false;
		if ($this->current_options['no_display_feed'] && is_feed()) $display = false;

		$footnotes = array();

		// Check if this post is using a different list style to the settings
		if ( array_key_exists(get_post_meta($post->ID, 'footnote_style', true), $this->styles) ) {
			$style = get_post_meta($post->ID, 'footnote_style', true);
		} else {
			$style = $this->current_options['list_style_type'];
		}

		// Create 'em
		for ($i=0; $i<count($identifiers); $i++){
			// Look for ref: and replace in identifiers array.
			if (substr($identifiers[$i][2],0,4) == 'ref:'){
				$ref = (int)substr($identifiers[$i][2],4);
				$identifiers[$i]['text'] = $identifiers[$ref-1][2];
			}else{
				$identifiers[$i]['text'] = $identifiers[$i][2];
			}


			// if we're combining identical notes check if we've already got one like this & record keys
			if ($this->current_options['combine_identical_notes']){
				for ($j=0; $j<count($footnotes); $j++){
					if ($footnotes[$j]['text'] == $identifiers[$i]['text']){
						$identifiers[$i]['use_footnote'] = $j;
						$footnotes[$j]['identifiers'][] = $i;
						break;
					}
				}
			}

			if (!isset($identifiers[$i]['use_footnote'])){
				// Add footnote and record the key
				$identifiers[$i]['use_footnote'] = count($footnotes);
				$footnotes[$identifiers[$i]['use_footnote']]['text'] = $identifiers[$i]['text'];
				$footnotes[$identifiers[$i]['use_footnote']]['symbol'] = $identifiers[$i]['symbol'];
				$footnotes[$identifiers[$i]['use_footnote']]['identifiers'][] = $i;
			}
		}

		// Footnotes and identifiers are stored in the array
		$use_full_link = false;

		if (is_feed()) $use_full_link = true;

		if (is_preview()) $use_full_link = false;

		// Display identifiers		
		foreach ($identifiers as $key => $value) {
			$id_id = "identifier_".$key."_".$post->ID;
			$id_num = ($style == 'decimal') ? $value['use_footnote']+$start_number : $this->convert_num($value['use_footnote']+$start_number, $style, count($footnotes));
			$id_href = ( ($use_full_link) ? get_permalink($post->ID) : '' ) . "#footnote_".$value['use_footnote']."_".$post->ID;

//			$id_title = str_replace('"', "&quot;", htmlentities(strip_tags($value['text']), ENT_QUOTES, 'UTF-8'));

			$id_title = str_replace('"', '`', strip_tags($value['text']));
			$id_replace = $this->current_options['pre_identifier'].'<a href="'.$id_href.'" id="'.$id_id.'" class="footnote-link footnote-identifier-link" title="'.$id_title.'">'.$id_num.'</a>'.$this->current_options['post_identifier'];
			if ($this->current_options['superscript']) $id_replace = '<sup>'.$id_replace.'</sup>';
			if ($display) $data = substr_replace($data, $id_replace, strpos($data,$value[0]),strlen($value[0]));
			else $data = substr_replace($data, '', strpos($data,$value[0]),strlen($value[0]));
		}

		// Display footnotes
		if ($display) {
			$start = ($start_number != 1) ? 'start="'.$start_number.'" ' : '';
			$data = $data.$this->current_options['pre_footnotes'];

			$data = $data . '<ol '.$start.'class="footnotes">';	
			foreach ($footnotes as $key => $value) {
				$data = $data.'<li id="footnote_'.$key.'_'.$post->ID.'" class="footnote"';
				if ($style == 'symbol') {
					$data = $data . ' style="list-style-type:none;"';
				} elseif($style != $this->current_options['list_style_type']) {
					$data = $data . ' style="list-style-type:' . $style . ';"';
				}
				$data = $data . '>';
				if ($style == 'symbol') {
					$data = $data . '<span class="symbol">' . $this->convert_num($key+$start_number, $style, count($footnotes)) . '</span> ';
				}
				$data = $data.$value['text'];
				if (!is_feed()){
					foreach($value['identifiers'] as $identifier){
						$data = $data.$this->current_options['pre_backlink'].'<a href="'.( ($use_full_link) ? get_permalink($post->ID) : '' ).'#identifier_'.$identifier.'_'.$post->ID.'" class="footnote-link footnote-back-link">'.$this->current_options['backlink'].'</a>'.$this->current_options['post_backlink'];
					}
				}
				$data = $data . '</li>';
			}
			$data = $data . '</ol>' . $this->current_options['post_footnotes'];
		}
		return $data;
	}

	/**
	 * Really insert the options page.
	 */
	function footnotes_options_page() { 
		$this->current_options = get_option('swas_footnote_options');
		foreach ($this->current_options as $key=>$setting) {
			$new_setting[$key] = htmlentities($setting);
		}
		$this->current_options = $new_setting;
		unset($new_setting);
		include (dirname(__FILE__) . '/options.php');
	}

	/**
	 * Insert the options page into the admin area.
	 */
	function add_options_page() {
		// Add a new menu under Options:
		add_options_page('Footnotes', 'Footnotes', 8, __FILE__, array($this, 'footnotes_options_page'));
	}

	function upgrade_post($data){
		$data = str_replace('<footnote>',WP_FOOTNOTES_OPEN,$data);
		$data = str_replace('</footnote>',WP_FOOTNOTES_CLOSE,$data);
		return $data;
	}

	function insert_styles(){
		?>
		<style type="text/css">
			<?php if ($this->current_options['list_style_type'] != 'symbol'): ?>
			ol.footnotes li {list-style-type:<?php echo $this->current_options['list_style_type']; ?>;}
			<?php endif; ?>
			<?php echo $this->current_options['style_rules'];?>
		</style>
		<?php
	}


	function convert_num ($num, $style, $total){
		switch ($style) {
			case 'decimal-leading-zero' :
				$width = max(2, strlen($total));
				return sprintf("%0{$width}d", $num);
			case 'lower-roman' :
				return $this->roman($num, 'lower');
			case 'upper-roman' :
				return $this->roman($num);
			case 'lower-alpha' :
				return $this->alpha($num, 'lower');
			case 'upper-alpha' :
				return $this->alpha($num);
			case 'symbol' :
				$sym = '';
				for ($i = 0; $i<$num; $i++) {
					$sym .= $this->current_options['list_style_symbol'];
				}
				return $sym;
		}
	}


	/**
	 * Convert to a roman numeral.
	 *
	 * Thanks to Indi.in.the.Wired for the improved algorithm.
	 * http://plugins.trac.wordpress.org/ticket/1177
	 *
	 * @param int $num The number to convert.
	 * @param string $case Upper or lower case.
	 * @return string The roman numeral
	 */
	function roman($num, $case= 'upper'){
		$num = (int) $num;
		$conversion = array('M'=>1000, 'CM'=>900, 'D'=>500, 'CD'=>400, 'C'=>100, 'XC'=>90, 'L'=>50, 'XL'=>40, 'X'=>10, 'IX'=>9, 'V'=>5, 'IV'=>4, 'I'=>1);
		$roman = '';

		foreach ($conversion as $r => $d){
			$roman .= str_repeat($r, (int)($num / $d));
			$num %= $d;
		}

		return ($case == 'lower') ? strtolower($roman) : $roman;
	}
	
	function alpha($num, $case='upper'){
		$j = 1;
		for ($i = 'A'; $i <= 'ZZ'; $i++){
			if ($j == $num){
				if ($case == 'lower')
					return strtolower($i);
				else
					return $i;
			}
			$j++;
		}
	}
}