<?php
/**
 * @package     Joomla.Platform
 * @subpackage  Application
 *
 * @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;

/**
 * Component helper class
 *
 * @package     Joomla.Platform
 * @subpackage  Application
 * @since       11.1
 */
class JComponentHelper
{
    /**
     * The component list cache
     *
     * @var     array
     * @since   11.1
     */
    protected static $_components = array();

    /**
     * Get the component information.
     *
     * @param   string  $option The component option.
     * @param   boolean $string If set and the component does not exist, the enabled attribue will be set to false
     *
     * @return  object  An object with the fields for the component.
     * @since   11.1
     */
    public static function getComponent($option, $strict = false)
    {
        if (!isset(self::$_components[$option])) {
            if (self::_load($option)){
                $result = self::$_components[$option];
            } else {
                $result             = new stdClass;
                $result->enabled    = $strict ? false : true;
                $result->params     = new JRegistry;
            }
        } else {
            $result = self::$_components[$option];
        }

        return $result;
    }

    /**
     * Checks if the component is enabled
     *
     * @param   string  $option The component option.
     * @param   boolean $string If set and the component does not exist, false will be returned
     *
     * @return  boolean
     * @since   11.1
     */
    public static function isEnabled($option, $strict = false)
    {
        $result = self::getComponent($option, $strict);

        return ($result->enabled | JFactory::getApplication()->isAdmin());
    }

    /**
     * Gets the parameter object for the component
     *
     * @param   string      The option for the component.
     * @param   boolean     If set and the component does not exist, false will be returned
     *
     * @return  JRegistry   As of 1.6, this method returns a JRegistry (previous versions returned JParameter).
     * @since   11.1
     */
    public static function getParams($option, $strict = false)
    {
        $component = self::getComponent($option, $strict);

        return $component->params;
    }

    /**
     * Render the component.
     *
     * @param   string  The component option.
     *
     * @return  void
     * @since   11.1
     */
    public static function renderComponent($option, $params = array())
    {
        // Initialise variables.
        $app    = JFactory::getApplication();

        // Load template language files.
        $template   = $app->getTemplate(true)->template;
        $lang = JFactory::getLanguage();
            $lang->load('tpl_'.$template, JPATH_BASE, null, false, false)
        ||  $lang->load('tpl_'.$template, JPATH_THEMES."/$template", null, false, false)
        ||  $lang->load('tpl_'.$template, JPATH_BASE, $lang->getDefault(), false, false)
        ||  $lang->load('tpl_'.$template, JPATH_THEMES."/$template", $lang->getDefault(), false, false);

        if (empty($option)) {
            // Throw 404 if no component
            JError::raiseError(404, JText::_('JLIB_APPLICATION_ERROR_COMPONENT_NOT_FOUND'));
            return;
        }

         // Record the scope
        $scope = $app->scope;
        // Set scope to component name
        $app->scope = $option;

        // Build the component path.
        $option = preg_replace('/[^A-Z0-9_\.-]/i', '', $option);
        $file   = substr($option, 4);

        // Define component path.
        define('JPATH_COMPONENT',               JPATH_BASE.DS.'components'.DS.$option);
        define('JPATH_COMPONENT_SITE',          JPATH_SITE.DS.'components'.DS.$option);
        define('JPATH_COMPONENT_ADMINISTRATOR', JPATH_ADMINISTRATOR.DS.'components'.DS.$option);

        // Get component path
        if ($app->isAdmin() && file_exists(JPATH_COMPONENT.DS.'admin.'.$file.'.php')) {
            $path = JPATH_COMPONENT.DS.'admin.'.$file.'.php';
        } else {
            $path = JPATH_COMPONENT.DS.$file.'.php';
        }

        // If component is disabled throw error
        if (!self::isEnabled($option) || !file_exists($path)) {
            JError::raiseError(404, JText::_('JLIB_APPLICATION_ERROR_COMPONENT_NOT_FOUND'));
        }

        $task = JRequest::getString('task');

        // Load common and local language files.
            $lang->load($option, JPATH_BASE, null, false, false)
        ||  $lang->load($option, JPATH_COMPONENT, null, false, false)
        ||  $lang->load($option, JPATH_BASE, $lang->getDefault(), false, false)
        ||  $lang->load($option, JPATH_COMPONENT, $lang->getDefault(), false, false);

        // Handle template preview outlining.
        $contents = null;

        // Execute the component.
        ob_start();
        require_once $path;
        $contents = ob_get_contents();
        ob_end_clean();

        // Build the component toolbar
        jimport('joomla.application.helper');

        if (($path = JApplicationHelper::getPath('toolbar')) && $app->isAdmin()) {
            // Get the task again, in case it has changed
            $task = JRequest::getString('task');

            // Make the toolbar
            include_once $path;
        }

        // Revert the scope
        $app->scope = $scope;

        return $contents;
    }

    /**
     * Load the installed components into the _components property.
     *
     * @return  boolean
     * @since   11.1
     */
    protected static function _load($option)
    {
        $db     = JFactory::getDbo();
        $query  = $db->getQuery(true);
        $query->select('extension_id AS "id", element AS "option", params, enabled');
        $query->from('#__extensions');
        $query->where('`type` = '.$db->quote('component'));
        $query->where('`element` = '.$db->quote($option));
        $db->setQuery($query);

        $cache = JFactory::getCache('_system','callback');

        self::$_components[$option] =  $cache->get(array($db, 'loadObject'), null, $option, false);

        if ($error = $db->getErrorMsg() || empty(self::$_components[$option])) {
            // Fatal error.
            JError::raiseWarning(500, JText::sprintf('JLIB_APPLICATION_ERROR_COMPONENT_NOT_LOADING', $option, $error));
            return false;
        }

        // Convert the params to an object.
        if (is_string(self::$_components[$option]->params)) {
            $temp = new JRegistry;
            $temp->loadJSON(self::$_components[$option]->params);
            self::$_components[$option]->params = $temp;
        }

        return true;
    }
}