<?php
class HTMLPurifier_Injector_RemoveEmpty extends HTMLPurifier_Injector {
	/**
	 * @type HTMLPurifier_Context
	 */
	private $context;
	
	/**
	 * @type HTMLPurifier_Config
	 */
	private $config;
	
	/**
	 * @type HTMLPurifier_AttrValidator
	 */
	private $attrValidator;
	
	/**
	 * @type bool
	 */
	private $removeNbsp;
	
	/**
	 * @type bool
	 */
	private $removeNbspExceptions;
	
	/**
	 * @type array
	 * TODO: make me configurable
	 */
	private $_exclude = array (
			'colgroup' => 1,
			'th' => 1,
			'td' => 1,
			'iframe' => 1 
	);
	
	/**
	 *
	 * @param HTMLPurifier_Config $config        	
	 * @param HTMLPurifier_Context $context        	
	 * @return void
	 */
	public function prepare($config, $context) {
		parent::prepare ( $config, $context );
		$this->config = $config;
		$this->context = $context;
		$this->removeNbsp = $config->get ( 'AutoFormat.RemoveEmpty.RemoveNbsp' );
		$this->removeNbspExceptions = $config->get ( 'AutoFormat.RemoveEmpty.RemoveNbsp.Exceptions' );
		$this->attrValidator = new HTMLPurifier_AttrValidator ();
	}
	
	/**
	 *
	 * @param HTMLPurifier_Token $token        	
	 */
	public function handleElement(&$token) {
		if (! $token instanceof HTMLPurifier_Token_Start) {
			return;
		}
		$next = false;
		$deleted = 1; // the current tag
		for($i = count ( $this->inputZipper->back ) - 1; $i >= 0; $i --, $deleted ++) {
			$next = $this->inputZipper->back [$i];
			if ($next instanceof HTMLPurifier_Token_Text) {
				if ($next->is_whitespace) {
					continue;
				}
				if ($this->removeNbsp && ! isset ( $this->removeNbspExceptions [$token->name] )) {
					$plain = str_replace ( "\xC2\xA0", "", $next->data );
					$isWsOrNbsp = $plain === '' || ctype_space ( $plain );
					if ($isWsOrNbsp) {
						continue;
					}
				}
			}
			break;
		}
		if (! $next || ($next instanceof HTMLPurifier_Token_End && $next->name == $token->name)) {
			if (isset ( $this->_exclude [$token->name] )) {
				return;
			}
			$this->attrValidator->validateToken ( $token, $this->config, $this->context );
			$token->armor ['ValidateAttributes'] = true;
			if (isset ( $token->attr ['id'] ) || isset ( $token->attr ['name'] )) {
				return;
			}
			$token = $deleted + 1;
			for($b = 0, $c = count ( $this->inputZipper->front ); $b < $c; $b ++) {
				$prev = $this->inputZipper->front [$b];
				if ($prev instanceof HTMLPurifier_Token_Text && $prev->is_whitespace) {
					continue;
				}
				break;
			}
			// This is safe because we removed the token that triggered this.
			$this->rewindOffset ( $b + $deleted );
			return;
		}
	}
}

// vim: et sw=4 sts=4