<?php
/**
 * Magento
 *
 * NOTICE OF LICENSE
 *
 * This source file is subject to the Open Software License (OSL 3.0)
 * that is bundled with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://opensource.org/licenses/osl-3.0.php
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@magentocommerce.com so we can send you a copy immediately.
 *
 * DISCLAIMER
 *
 * Do not edit or add to this file if you wish to upgrade Magento to newer
 * versions in the future. If you wish to customize Magento for your
 * needs please refer to http://www.magentocommerce.com for more information.
 *
 * @category    Mage
 * @package     Mage_Core
 * @copyright   Copyright (c) 2012 Magento Inc. (http://www.magentocommerce.com)
 * @license     http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 */

/**
 * JavaScript helper
 *
 * @author      Magento Core Team <core@magentocommerce.com>
 */
class Mage_Core_Helper_Js extends Mage_Core_Helper_Abstract
{
    /**
     * Key for cache
     */
    const JAVASCRIPT_TRANSLATE_CONFIG_KEY = 'javascript_translate_config';

    /**
     * Translate file name
     */
    const JAVASCRIPT_TRANSLATE_CONFIG_FILENAME = 'jstranslator.xml';

    /**
     * Array of senteces of JS translations
     *
     * @var array
     */
    protected $_translateData = null;

    /**
     * Translate config
     *
     * @var Varien_Simplexml_Config
     */
    protected $_config = null;

    /**
     * Retrieve JSON of JS sentences translation
     *
     * @return string
     */
    public function getTranslateJson()
    {
        return Mage::helper('core')->jsonEncode($this->_getTranslateData());
    }

    /**
     * Retrieve JS translator initialization javascript
     *
     * @return string
     */
    public function getTranslatorScript()
    {
        $script = 'var Translator = new Translate('.$this->getTranslateJson().');';
        return $this->getScript($script);
    }

    /**
     * Retrieve framed javascript
     *
     * @param   string $script
     * @return  script
     */
    public function getScript($script)
    {
        return '<script type="text/javascript">//<![CDATA[
        '.$script.'
        //]]></script>';
    }

    /**
     * Retrieve javascript include code
     *
     * @param   string $file
     * @return  string
     */
    public function includeScript($file)
    {
        return '<script type="text/javascript" src="'.$this->getJsUrl($file).'"></script>'."\n";
    }

    /**
     * Retrieve
     *
     * @param   string $file
     * @return  string
     */
    public function includeSkinScript($file)
    {
        return '<script type="text/javascript" src="'.$this->getJsSkinUrl($file).'"></script>';
    }

    /**
     * Retrieve JS file url
     *
     * @param   string $file
     * @return  string
     */
    public function getJsUrl($file)
    {
        return Mage::getBaseUrl('js').$file;
    }

    /**
     * Retrieve skin JS file url
     *
     * @param   string $file
     * @return  string
     */
    public function getJsSkinUrl($file)
    {
        return Mage::getDesign()->getSkinUrl($file, array());
    }

    /**
     * Retrieve JS translation array
     *
     * @return array
     */
    protected function _getTranslateData()
    {
        if ($this->_translateData === null) {
            $this->_translateData = array();
            $messages = $this->_getXmlConfig()->getXpath('*/message');
            if (!empty($messages)) {
                foreach ($messages as $message) {
                    $messageText = (string)$message;
                    $module = $message->getParent()->getAttribute("module");
                    $this->_translateData[$messageText] = Mage::helper(empty($module) ? 'core' : $module
                    )->__($messageText);
                }
            }

            foreach ($this->_translateData as $key => $value) {
                if ($key == $value) {
                    unset($this->_translateData[$key]);
                }
            }
        }
        return $this->_translateData;
    }

    /**
     * Load config from files and try to cache it
     *
     * @return Varien_Simplexml_Config
     */
    protected function _getXmlConfig()
    {
        if (is_null($this->_config)) {
            $canUsaCache = Mage::app()->useCache('config');
            $cachedXml = Mage::app()->loadCache(self::JAVASCRIPT_TRANSLATE_CONFIG_KEY);
            if ($canUsaCache && $cachedXml) {
                $xmlConfig = new Varien_Simplexml_Config($cachedXml);
            } else {
                $xmlConfig = new Varien_Simplexml_Config();
                $xmlConfig->loadString('<?xml version="1.0"?><jstranslator></jstranslator>');
                Mage::getConfig()->loadModulesConfiguration(self::JAVASCRIPT_TRANSLATE_CONFIG_FILENAME, $xmlConfig);

                if ($canUsaCache) {
                    Mage::app()->saveCache($xmlConfig->getXmlString(), self::JAVASCRIPT_TRANSLATE_CONFIG_KEY,
                        array(Mage_Core_Model_Config::CACHE_TAG));
                }
            }
            $this->_config = $xmlConfig;
        }
        return $this->_config;
    }
}
