<?php
/**
 * Класс базы данных.
 * Возвращает идентификатор соединения
 *
 * @copyright NetMonsters <team@netmonsters.ru>
 * @link
 * @package Majestic
 * @subpackage DB
 * @since
 * @version SVN: $Id$
 * @filesource $URL$
 */
class DBConnector
{

    /**
     * PDO constant values.
     */
    const FETCH_ASSOC = 2;
    const FETCH_BOTH  = 4;
    const FETCH_NUM   = 3;
    const FETCH_OBJ   = 5;

    static private $handlers = array();
    static public $queries   = array();

    /**
     * Запрещаем new и клонирование
     */
    private function __construct(){}

    private function __clone(){}

    /**
     * Получение соединения.
     * Если соединение с такими параметрами уже есть - новое не создается.
     *
     * @param array $db_settings - массив настроек
     * @return resource - идентификатор соединения
     */
    static public function getConnect($db_settings)
    {
        $handler_name = self::getConnectionName($db_settings);

        if (isset(self::$handlers[$handler_name])) {
            return self::$handlers[$handler_name];
        }

        if (!$handler = mysqli_connect($db_settings['host'], $db_settings['user'], $db_settings['password'], $db_settings['database'])) {
            throw new MJException('Can\'t connect to DB '.mysqli_connect_error(), 2);
        }

        self::query($handler, "SET NAMES 'utf8'"); //cheat!!!
        return self::$handlers[$handler_name] = $handler;
    }

    static protected function getConnectionName($db_settings)
    {
        return $db_settings['host'] . '-' . $db_settings['database'];
    }

/////////

    static public function query($handler, $sql)
    {
        return mysqli_query($handler, $sql);
    }

    static public function escape($handler, $str)
    {
        return mysqli_real_escape_string($handler, $str);
    }

    static public function error($handler)
    {
        return mysqli_error($handler);
    }

    static public function free($result)
    {
        return mysqli_free_result($result);
    }

    static public function fetchObject($result, $class_name = false)
    {
        return $class_name ? mysqli_fetch_object($result, $class_name) : mysqli_fetch_object($result);
    }

    /**
     * Fetches a row from the result set.
     *
     * @param mysqli_result $result
     * @param int $style OPTIONAL Fetch mode for this fetch operation.
     * @return mixed Array, object, or scalar depending on fetch mode.
     * @throws Exception
     */
    static public function fetchArray($result, $style = null)
    {
        if (!$result) {
            return false;
        }

        if ($style === null) {
            $style = self::FETCH_ASSOC;
        }

        $row = false;
        switch ($style) {
            case self::FETCH_NUM:
                $row = mysqli_fetch_array($result, MYSQLI_NUM);
            break;
            case self::FETCH_ASSOC:
                $row = mysqli_fetch_array($result, MYSQLI_ASSOC);
            break;
            case self::FETCH_BOTH:
                $row = mysqli_fetch_array($result, MYSQLI_BOTH);
                break;
            case self::FETCH_OBJ:
                $row = mysqli_fetch_object($result, MYSQLI_BOTH);
                break;
            default:
                throw new Exception('Invalid fetch mode "' . $style . '" specified');
                break;
        }
        return $row;
    }

    static public function numRows($result)
    {
        return mysqli_num_rows($result);
    }

    static public function affectedRows($handler, $result)
    {
        return mysqli_affected_rows($handler);
    }

    static public function getId($handler)
    {
        return mysqli_insert_id($handler);
    }

    static public function autocommit($handler, $switch)
    {
        return mysqli_autocommit($handler, (bool) $switch);
    }

    static public function commit($handler)
    {
        return mysqli_commit($handler);
    }

    static public function rollback($handler)
    {
        return mysqli_rollback($handler);
    }
}
?>