<?php
/**
 * Markup Validator: Html
 *
 * $Id$
 *
 * @author gERD Schaufelberger <gerd@php-tools.net>
 * @license PHP License
 * @package wb
 * @subpackage Markup
 */

WBClass::load('WBMarkup_Validator');

/**
 * Markup Validator: Html
 *
 * Validator for simple HTML elements
 *
 * @version 0.2.0
 * @package wb
 * @subpackage Markup
 */
class WBMarkup_Validator_Html extends WBMarkup_Validator
{
    /**
     * Validator's config
     *
     * @var array
     */
    protected $config   =   array(
                                    'heading'   =>  array(
                                                        1,
                                                        2,
                                                        3,
                                                        4,
                                                        5,
                                                        6
                                                    ),
                                    'markup'    =>  array(),
                                    'paragraph' =>  array('p', 'br', 'hr'),
                                    'list'      =>  array('ul', 'ol')
                                );


   /**
    * Validate tags
    *
    * @param string $ns
    * @param string $tag
    * @param array $attributes
    * @param bool $isEmpty
    * @return bool
    */
    public function validateStartElement($ns, $tag, $attributes, $isEmpty)
    {
        $this->flushError();
        
        if (!empty($ns)) {
            return false;
        }
        
        // internal HTML validator
        if ($this->validateHeading($tag, $attributes)) {
            return true;
        }
        if ($this->validateParagraph($tag, $attributes)) {
            return true;
        }
        if ($this->validateMarkup($tag, $attributes)) {
            return true;
        }
        if ($this->validateList($tag, $attributes)) {
            return true;
        }
    
        return false;
    }
    
    /**
     * Validate Heading Tag
     * 
     * 
     * 
     * @param string $tag named tag
     * @param array $attributes
     * @return true if tag is a relevant tag for this validator
     */
    private function validateHeading($tag, $attributes)
    {
        if (2 != strlen($tag) || 'h' != $tag[0]) {
            return false;
        }

        if (!is_numeric($tag[1])) {
            return false;
        }
        
        if (!is_array($this->config['heading']) || empty($this->config['heading'])) {
            $this->setError(1, 'Headings are not allowed.');
            return true;
        }
        
        $n  =   $tag[1];
        if (in_array($tag[1], $this->config['heading'])) {
            return true;
        }
        
        $this->setError(intval($tag[1]) + 1, 'Heading level ' . $tag[1] . ' is not allowed.');
        return true;
    }

    /**
     * Validate Paragraph 
     * 
     * <p>, <br /> and <hr /> are valid tags.
     * 
     * @param string $tag named tag
     * @param array $attributes
     * @return true if tag is a relevant tag for this validator
     */
    private function validateParagraph($tag, $attributes)
    {
        if  ('p' == $tag) {
            if (in_array('p', $this->config['paragraph'])) {
                return true;
            }
            $this->setError(11, 'Paragraphs are not allowed.');
            return true;
        }
        
        if  ('br' == $tag) {
            if (in_array('br', $this->config['paragraph'])) {
                return true;
            }
            $this->setError(12, 'Line breaks are not allowed.');
            return true;
        }
        if  ('hr' == $tag) {
            if (in_array('hr', $this->config['paragraph'])) {
                return true;
            }
            $this->setError(13, 'Horizontal rules are not allowed.');
            return true;
        }
        return false;
    }

    /**
     * Validate Markup Tag
     * 
     * 
     * 
     * @param string $tag named tag
     * @param array $attributes
     * @return true if tag is a relevant tag for this validator
     */
    private function validateMarkup($tag, $attributes)
    {
        // $this->setError(21, 'Paragraphs are not allowed.');
        return false;
    }
    
    /**
     * Validate List Tags
     * 
     * 
     * 
     * @param string $tag named tag
     * @param array $attributes
     * @return true if tag is a relevant tag for this validator
     */
    private function validateList($tag, $attributes)
    {
        if (!in_array($tag, array('ul', 'ol', 'li'))) {
            return false;
        }
        
        if  ('ul' == $tag) {
            if (in_array('ul', $this->config['list'])) {
                return true;
            }
            $this->setError(31, 'Unordered lists are not allowed');
            return true;
        }
        if  ('ol' == $tag) {
            if (in_array('ol', $this->config['list'])) {
                return true;
            }
            $this->setError(32, 'Ordered lists are not allowed');
            return true;
        }        
        if  ('li' == $tag) {
            if (empty($this->config['list'])) {
                $this->setError(32, 'Lists and list items are not allowed');
            }
            return true;
        }
        return true;
    }    
}