<?php

class DB extends KD2\DB\DB
{
    const FETCH_ASSOC = PDO::FETCH_ASSOC;
    const FETCH_NUM = PDO::FETCH_NUM;
    const FETCH_BOTH = PDO::FETCH_BOTH;

    static private $_instance;

    static public function getInstance()
    {
        if (null === self::$_instance) {
            self::$_instance = new DB('mysql', ['host' => MYSQL_HOST, 'user' => MYSQL_USER, 'password' => MYSQL_PASS, 'database' => MYSQL_BASE]);
        }

        return self::$_instance;
    }

    public static function startMultipleQueries($connection=false)
    {
        self::getInstance()->begin();
    }

    public static function endMultipleQueries($connection=false)
    {
        self::getInstance()->commit();
    }

    public static function isMultiple($connection=false)
    {
        return self::getInstance()->inTransaction();
    }

    public static function query2($query, $connection=false)
    {
        $st = self::getInstance()->prepare($query);
        $st->execute();
        return $st;
    }

    public static function fetchRow($result, $fetch_mode=false)
    {
        if (!$fetch_mode)
            $fetch_mode = self::FETCH_BOTH;

        return $result->fetch($fetch_mode);
    }

    public static function arrayQuery($query, $connection=false, $fetch_mode=false)
    {
        if (!$fetch_mode)
            $fetch_mode = self::FETCH_BOTH;

        $result = self::query2($query);

        if(!$result)
        {
            return false;
        }

        return $result->fetchAll($fetch_mode);
    }

    public static function unbufferedQuery($query, $connection=false)
    {
        return self::query2($query, $connection);
    }

    public static function execQuery($query, $connection=false)
    {
        return self::query2($query, $connection);
    }

    public static function q($query, $connection=false)
    {
        return self::query2($query, $connection);
    }

    public static function aQuery($query, $connection=false, $fetch_mode=false)
    {
        return self::arrayQuery($query, $connection, $fetch_mode);
    }

    public static function uQuery($query, $connection=false)
    {
        return self::unbufferedQuery($query, $connection);
    }

    public static function eQuery($query)
    {
        return self::execQuery($query);
    }

    public static function getInsertId($connection=false)
    {
        return self::getInstance()->lastInsertId();
    }

    public static function numRows($result)
    {
        return $result->rowCount();
    }

    public static function escape($str, $connection=false)
    {
        if (is_array($str) || is_object($str))
            throw new DB_Exception("Trying to escape non-string variable of type ".gettype($str).": ".print_r($str, true));

        return substr(self::getInstance()->quote($str), 1, -1);
    }

    public static function e($str, $connection=false)
    {
        return self::escape($str, $connection);
    }

    public static function esc($str, $connection=false)
    {
        return self::escape($str, $connection);
    }
}