<?php
/**
 * @package     Joomla.Platform
 * @subpackage  Updater
 *
 * @copyright   Copyright (C) 2005 - 2011 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE
 */

defined('JPATH_PLATFORM') or die;

/**
 * Update class.
 *
 * @package     Joomla.Platform
 * @subpackage  Update
 * @since       11.1
 */
class JUpdate extends JObject
{
    protected $name;
    protected $description;
    protected $element;
    protected $type;
    protected $version;
    protected $infourl;
    protected $client;
    protected $group;
    protected $downloads;
    protected $tags;
    protected $maintainer;
    protected $maintainerurl;
    protected $category;
    protected $relationships;
    protected $targetplatform;

    private $_xml_parser;
    private $_stack = Array('base');
    private $_state_store = Array();

    /**
     * Gets the reference to the current direct parent
     *
     * @return object
     */
    protected function _getStackLocation()
    {
            return implode('->', $this->_stack);
    }

    /**
     * Get the last position in stack count
     *
     * @return string
     */
    protected function _getLastTag()
    {
        return $this->_stack[count($this->_stack) - 1];
    }

    /**
     * XML Start Element callback
     * Note: This is public because it is called externally
     * @param object parser object
     * @param string name of the tag found
     * @param array attributes of the tag
     * 
     */
    public function _startElement($parser, $name, $attrs = Array())
    {
        array_push($this->_stack, $name);
        $tag = $this->_getStackLocation();
        // Reset the data
        eval('$this->'. $tag .'->_data = "";');

        switch($name) {
            // This is a new update; create a current update
            case 'UPDATE': 
                $this->_current_update = new stdClass();
                break;
            // Don't do anything
            case 'UPDATES': 
                break;
            // For everything else there's...the default!
            default: 
                $name = strtolower($name);
                $this->_current_update->$name->_data = '';
                foreach($attrs as $key=>$data) {
                    $key = strtolower($key);
                    $this->_current_update->$name->$key = $data;
                }
                break;
        }
    }

    /**
     * Callback for closing the element
     * Note: This is public because it is called externally
     * 
     * @param object parser object
     * @param string name of element that was closed
     */
    public function _endElement($parser, $name)
    {
        array_pop($this->_stack);
        switch($name)
        {
            // Closing update, find the latest version and check
            case 'UPDATE': 
                $ver = new JVersion();
                $product = strtolower(JFilterInput::getInstance()->clean($ver->PRODUCT, 'cmd'));
                if($product == $this->_current_update->targetplatform->name && $ver->RELEASE == $this->_current_update->targetplatform->version)
                {
                    if(isset($this->_latest))
                    {
                        if(version_compare($this->_current_update->version->_data, $this->_latest->version->_data, '>') == 1) {
                            $this->_latest = $this->_current_update;
                        }
                    }
                    else {
                        $this->_latest = $this->_current_update;
                    }
                }
                break;
            case 'UPDATES':
                // If the latest item is set then we transfer it to where we want to
                if(isset($this->_latest))
                {
                    foreach(get_object_vars($this->_latest) as $key=>$val) {
                        $this->$key = $val;
                    }
                    unset($this->_latest);
                    unset($this->_current_update);
                }
                else if(isset($this->_current_update))
                {
                    // The update might be for an older version of j!
                    unset($this->_current_update);
                }
                break;
        }
    }

    /**
     * Character Parser Function
     * Note: This is public because its called externally
     * 
     * @param       data
     * @param       parser
     * 
     */
    public function _characterData($parser, $data) {
        $tag = $this->_getLastTag();
        //if(!isset($this->$tag->_data)) $this->$tag->_data = '';
        //$this->$tag->_data .= $data;
        // Throw the data for this item together
        $tag = strtolower($tag);
        $this->_current_update->$tag->_data .= $data;
    }

    public function loadFromXML($url)
    {
        if (!($fp = @fopen($url, "r")))
        {
            // TODO: Add a 'mark bad' setting here somehow
            JError::raiseWarning('101', JText::sprintf('JLIB_UPDATER_ERROR_EXTENSION_OPEN_URL', $url));
            return false;
        }

        $this->xml_parser = xml_parser_create('');
        xml_set_object($this->xml_parser, $this);
        xml_set_element_handler($this->xml_parser, '_startElement', '_endElement');
        xml_set_character_data_handler($this->xml_parser, '_characterData');

        while ($data = fread($fp, 8192))
        {
            if (!xml_parse($this->xml_parser, $data, feof($fp)))
            {
                die(sprintf("XML error: %s at line %d",
                            xml_error_string(xml_get_error_code($this->xml_parser)),
                            xml_get_current_line_number($this->xml_parser)));
            }
        }
        xml_parser_free($this->xml_parser);
        return true;
    }
}