<?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_Install
 * @copyright   Copyright (c) 2010 Magento Inc. (http://www.magentocommerce.com)
 * @license     http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 */

/**
 * DB Installer
 *
 * @category   Mage
 * @package    Mage_Install
 * @author      Magento Core Team <core@magentocommerce.com>
 */
class Mage_Install_Model_Installer_Db extends Mage_Install_Model_Installer_Abstract
{
    /**
     * Check database connection
     *
     * $data = array(
     *      [db_host]
     *      [db_name]
     *      [db_user]
     *      [db_pass]
     * )
     *
     * @param array $data
     */
    public function checkDatabase($data)
    {
        $config = array(
            'host'      => $data['db_host'],
            'username'  => $data['db_user'],
            'password'  => $data['db_pass'],
            'dbname'    => $data['db_name']
        );

        try {
            $connection = Mage::getSingleton('core/resource')->createConnection('install', $this->_getConnenctionType(), $config);
            $variables  = $connection->fetchPairs("SHOW VARIABLES");

            $version = isset($variables['version']) ? $variables['version'] : 'undefined';
            $match = array();
            if (preg_match("#^([0-9\.]+)#", $version, $match)) {
                $version = $match[0];
            }
            $requiredVersion = (string)Mage::getSingleton('install/config')->getNode('check/mysql/version');

            // check MySQL Server version
            if (version_compare($version, $requiredVersion) == -1) {
                Mage::throwException(Mage::helper('install')->__('The database server version does not match system requirements (required: %s, actual: %s).', $requiredVersion, $version));
            }

            // check InnoDB support
            if (!isset($variables['have_innodb']) || $variables['have_innodb'] != 'YES') {
                Mage::throwException(Mage::helper('install')->__('Database server does not support the InnoDB storage engine.'));
            }
        }
        catch (Exception $e){
            $this->_getInstaller()->getDataModel()->addError($e->getMessage());
            Mage::throwException(Mage::helper('install')->__('Database connection error.'));
        }
    }

    /**
     * Retrieve Connection Type
     *
     * @return string
     */
    protected function _getConnenctionType()
    {
        return (string) Mage::getConfig()->getNode('global/resources/default_setup/connection/type');
    }
}