/*
 balanceTags
 
 Balances Tags of string using a modified stack.
 
 @param text      Text to be balanced
 @return          Returns balanced text
 @author          Leonard Lin (leonard@acm.org)
 @version         v1.1
 @date            November 4, 2001
 @license         GPL v2.0
 @notes           
 @changelog       
 ---  Modified by Scott Reilly (coffee2code) 02 Aug 2004
             1.2  ***TODO*** Make better - change loop condition to $text
             1.1  Fixed handling of append/stack pop order of end text
                  Added Cleaning Hooks
             1.0  First Version
*/
function balanceTags($text, $is_comment = 0) {
	
	if ( get_option('use_balanceTags') == 0)
		return $text;

	$tagstack = array(); $stacksize = 0; $tagqueue = ''; $newtext = '';

	# WP bug fix for comments - in case you REALLY meant to type '< !--'
	$text = str_replace('< !--', '<    !--', $text);
	# WP bug fix for LOVE <3 (and other situations with '<' before a number)
	$text = preg_replace('#<([0-9]{1})#', '&lt;$1', $text);

	while (preg_match("/<(\/?\w*)\s*([^>]*)>/",$text,$regex)) {
		$newtext .= $tagqueue;

		$i = strpos($text,$regex[0]);
		$l = strlen($regex[0]);

		// clear the shifter
		$tagqueue = '';
		// Pop or Push
		if ($regex[1][0] == "/") { // End Tag
			$tag = strtolower(substr($regex[1],1));
			// if too many closing tags
			if($stacksize <= 0) { 
				$tag = '';
				//or close to be safe $tag = '/' . $tag;
			}
			// if stacktop value = tag close value then pop
			else if ($tagstack[$stacksize - 1] == $tag) { // found closing tag
				$tag = '</' . $tag . '>'; // Close Tag
				// Pop
				array_pop ($tagstack);
				$stacksize--;
			} else { // closing tag not at top, search for it
				for ($j=$stacksize-1;$j>=0;$j--) {
					if ($tagstack[$j] == $tag) {
					// add tag to tagqueue
						for ($k=$stacksize-1;$k>=$j;$k--){
							$tagqueue .= '</' . array_pop ($tagstack) . '>';
							$stacksize--;
						}
						break;
					}
				}
				$tag = '';
			}
		} else { // Begin Tag
			$tag = strtolower($regex[1]);

			// Tag Cleaning

			// If self-closing or '', don't do anything.
			if((substr($regex[2],-1) == '/') || ($tag == '')) {
			}
			// ElseIf it's a known single-entity tag but it doesn't close itself, do so
			elseif ($tag == 'br' || $tag == 'img' || $tag == 'hr' || $tag == 'input') {
				$regex[2] .= '/';
			} else {	// Push the tag onto the stack
				// If the top of the stack is the same as the tag we want to push, close previous tag
				if (($stacksize > 0) && ($tag != 'div') && ($tagstack[$stacksize - 1] == $tag)) {
					$tagqueue = '</' . array_pop ($tagstack) . '>';
					$stacksize--;
				}
				$stacksize = array_push ($tagstack, $tag);
			}

			// Attributes
			$attributes = $regex[2];
			if($attributes) {
				$attributes = ' '.$attributes;
			}
			$tag = '<'.$tag.$attributes.'>';
			//If already queuing a close tag, then put this tag on, too
			if ($tagqueue) {
				$tagqueue .= $tag;
				$tag = '';
			}
		}
		$newtext .= substr($text,0,$i) . $tag;
		$text = substr($text,$i+$l);
	}  

	// Clear Tag Queue
	$newtext .= $tagqueue;

	// Add Remaining text
	$newtext .= $text;

	// Empty Stack
	while($x = array_pop($tagstack)) {
		$newtext .= '</' . $x . '>'; // Add remaining tags to close
	}

	// WP fix for the bug with HTML comments
	$newtext = str_replace("< !--","<!--",$newtext);
	$newtext = str_replace("<    !--","< !--",$newtext);

	return $newtext;
}