* Link: http://code.shishnet.org/shimmie2/
 * License: GPLv2
 * Description: Turns BBCode into HTML
 * Documentation:
 *  Supported tags:
 *  
 *    - [img]url[/img]
 *    
- [url]http://code.shishnet.org/[/url]
 *    
- [email]webmaster@shishnet.org[/email]
 *    
- [b]bold[/b]
 *    
- [i]italic[/i]
 *    
- [u]underline[/u]
 *    
- [s]strikethrough[/s]
 *
- [[wiki article]]
 *    
- [[wiki article|with some text]]
 *    
- [quote]text[/quote]
 *    
- [quote=Username]text[/quote]
 *    
- >>123 (link to image #123)
 *  
*/
class BBCode extends FormatterExtension {
	public function format(/*string*/ $text) {
		global $config;
		if($config->get_bool("word_wrap", true)) {
			$text = wordwrap($text, 80, " ", true);
		}
		$text = preg_replace_callback("/(\[img\]https?:\/\/.*?\[\/img\])/s", array($this, "unwrap"), $text);
		$text = preg_replace_callback("/(\[url=(?:https?|ftp|irc|mailto):\/\/.*?\])/s", array($this, "unwrap"), $text);
		$text = preg_replace_callback("/(\[url\](?:https?|ftp|irc|mailto):\/\/.*?\[\/url\])/s", array($this, "unwrap"), $text);
		$text = $this->extract_code($text);
		$text = preg_replace("/\[b\](.*?)\[\/b\]/s", "\\1", $text);
		$text = preg_replace("/\[i\](.*?)\[\/i\]/s", "\\1", $text);
		$text = preg_replace("/\[u\](.*?)\[\/u\]/s", "\\1", $text);
		$text = preg_replace("/\[s\](.*?)\[\/s\]/s", "\\1", $text);
		$text = preg_replace("/>>(\d+)(#(\d+))?/s", ">>\\1\\2", $text);
		$text = preg_replace("/(^|\s)#(\d+)/s", "\\1#\\2", $text);
		$text = preg_replace("/>>([^\d].+)/", "\\1
", $text);
		$text = preg_replace("/\[url=((?:https?|ftp|irc|mailto):\/\/.*?)\](.*?)\[\/url\]/s", "\\2", $text);
		$text = preg_replace("/\[url\]((?:https?|ftp|irc|mailto):\/\/.*?)\[\/url\]/s", "\\1", $text);
		$text = preg_replace("/\[email\](.*?)\[\/email\]/s", "\\1", $text);
		$text = preg_replace("/\[img\](https?:\/\/.*?)\[\/img\]/s", " ", $text);
		$text = preg_replace("/\[\[([^\|\]]+)\|([^\]]+)\]\]/s", "\\2", $text);
		$text = preg_replace("/\[\[([^\]]+)\]\]/s", "\\1", $text);
		$text = preg_replace("/\n\s*\n/", "\n\n", $text);
		$text = str_replace("\n", "\n
", $text);
		$text = preg_replace("/\[\[([^\|\]]+)\|([^\]]+)\]\]/s", "\\2", $text);
		$text = preg_replace("/\[\[([^\]]+)\]\]/s", "\\1", $text);
		$text = preg_replace("/\n\s*\n/", "\n\n", $text);
		$text = str_replace("\n", "\n
", $text);
		$text = preg_replace("/\[quote\](.*?)\[\/quote\]/s", "\\1
", $text);
		$text = preg_replace("/\[quote=(.*?)\](.*?)\[\/quote\]/s", "\\1 said:
\\2
", $text);
		$text = preg_replace("/\[h1\](.*?)\[\/h1\]/s", "\\1
", $text);
		$text = preg_replace("/\[h2\](.*?)\[\/h2\]/s", "\\1
", $text);
		$text = preg_replace("/\[h3\](.*?)\[\/h3\]/s", "\\1
", $text);
		$text = preg_replace("/\[h4\](.*?)\[\/h4\]/s", "\\1
", $text);
		while(preg_match("/\[list\](.*?)\[\/list\]/s", $text))
			$text = preg_replace("/\[list\](.*?)\[\/list\]/s", "", $text);
		while(preg_match("/\[ul\](.*?)\[\/ul\]/s", $text))
			$text = preg_replace("/\[ul\](.*?)\[\/ul\]/s", "", $text);
		while(preg_match("/\[ol\](.*?)\[\/ol\]/s", $text))
			$text = preg_replace("/\[ol\](.*?)\[\/ol\]/s", "\\1
", $text);
		$text = preg_replace("/\[li\](.*?)\[\/li\]/s", "\\1", $text);
		$text = preg_replace("#\[\*\]#s", "", $text);
		$text = preg_replace("#
<(li|ul|ol|/ul|/ol)>#s", "<\\1>", $text);
		$text = preg_replace("#\[align=(left|center|right)\](.*?)\[\/align\]#s", "\\2
", $text);
		$text = $this->filter_spoiler($text);
		$text = $this->insert_code($text);
		return $text;
	}
	private function unwrap($matches) {
		return str_replace(' ', '', $matches[1]);
	}
	public function strip(/*string*/ $text) {
		global $config;
		if($config->get_bool("word_wrap", true)) {
			$text = wordwrap($text, 80, " ", true);
		}
		$text = preg_replace("/\[b\](.*?)\[\/b\]/s", "\\1", $text);
		$text = preg_replace("/\[i\](.*?)\[\/i\]/s", "\\1", $text);
		$text = preg_replace("/\[u\](.*?)\[\/u\]/s", "\\1", $text);
		$text = preg_replace("/\[s\](.*?)\[\/s\]/s", "\\1", $text);
		$text = preg_replace("/\[code\](.*?)\[\/code\]/s", "\\1", $text);
		$text = preg_replace("/\[url=(.*?)\](.*?)\[\/url\]/s", "\\2", $text);
		$text = preg_replace("/\[url\](.*?)\[\/url\]/s", "\\1", $text);
		$text = preg_replace("/\[email\](.*?)\[\/email\]/s", "\\1", $text);
		$text = preg_replace("/\[img\](.*?)\[\/img\]/s", "", $text);
		$text = preg_replace("/\[\[([^\|\]]+)\|([^\]]+)\]\]/s", "\\2", $text);
		$text = preg_replace("/\[\[([^\]]+)\]\]/s", "\\1", $text);
		$text = preg_replace("/\[quote\](.*?)\[\/quote\]/s", "", $text);
		$text = preg_replace("/\[quote=(.*?)\](.*?)\[\/quote\]/s", "", $text);
		$text = preg_replace("/\[h1\](.*?)\[\/h1\]/s", "\\1", $text);
		$text = preg_replace("/\[h2\](.*?)\[\/h2\]/s", "\\1", $text);
		$text = preg_replace("/\[h3\](.*?)\[\/h3\]/s", "\\1", $text);
		$text = preg_replace("/\[h4\](.*?)\[\/h4\]/s", "\\1", $text);
		$text = preg_replace("/\[\/?(list|ul|ol)\]/", "", $text);
		$text = preg_replace("/\[li\](.*?)\[\/li\]/s", "\\1", $text);
		$text = preg_replace("/\[\*\](.*?)/s", "\\1", $text);
		$text = $this->strip_spoiler($text);
		return $text;
	}
	private function filter_spoiler(/*string*/ $text) {
		return str_replace(
			array("[spoiler]","[/spoiler]"),
			array("",""),
			$text);
	}
	private function strip_spoiler(/*string*/ $text) {
		$l1 = strlen("[spoiler]");
		$l2 = strlen("[/spoiler]");
		while(true) {
			$start = strpos($text, "[spoiler]");
			if($start === false) break;
			$end = strpos($text, "[/spoiler]");
			if($end === false) break;
			$beginning = substr($text, 0, $start);
			$middle = str_rot13(substr($text, $start+$l1, ($end-$start-$l1)));
			$ending = substr($text, $end + $l2, (strlen($text)-$end+$l2));
			$text = $beginning . $middle . $ending;
		}
		return $text;
	}
	private function extract_code(/*string*/ $text) {
		# at the end of this function, the only code! blocks should be
		# the ones we've added -- others may contain malicious content,
		# which would only appear after decoding
		$text = str_replace("[code!]", "[code]", $text);
		$text = str_replace("[/code!]", "[/code]", $text);
		$l1 = strlen("[code]");
		$l2 = strlen("[/code]");
		while(true) {
			$start = strpos($text, "[code]");
			if($start === false) break;
			$end = strpos($text, "[/code]", $start);
			if($end === false) break;
			$beginning = substr($text, 0, $start);
			$middle = base64_encode(substr($text, $start+$l1, ($end-$start-$l1)));
			$ending = substr($text, $end + $l2, (strlen($text)-$end+$l2));
			$text = $beginning . "[code!]" . $middle . "[/code!]" . $ending;
		}
		return $text;
	}
	private function insert_code(/*string*/ $text) {
		$l1 = strlen("[code!]");
		$l2 = strlen("[/code!]");
		while(true) {
			$start = strpos($text, "[code!]");
			if($start === false) break;
			$end = strpos($text, "[/code!]");
			if($end === false) break;
			$beginning = substr($text, 0, $start);
			$middle = base64_decode(substr($text, $start+$l1, ($end-$start-$l1)));
			$ending = substr($text, $end + $l2, (strlen($text)-$end+$l2));
			$text = $beginning . "" . $middle . "
" . $ending;
		}
		return $text;
	}
}
?>