<?php

class MySQL {

    private $_instance;
    private $_mysqli;

    public function __construct() {
        $this->_mysqli = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME);
        if ($this->_mysqli->connect_error) {
            var_dump($this->_mysqli->connect_error);
            exit;
        } else {
            return $this->runQuery('SET NAMES UTF8');
        }
    }

    public static function getInstance() {
        if (!isset(self::$_instance)) {
            $c = __CLASS__;
            self::$_instance = new $c;
        }

        return self::$_instance;
    }

    public function runQuery($sql, $resultModel = MYSQLI_STORE_RESULT) {
        $result = $this->_mysqli->query($sql, $resultModel);
        if (!$this->_mysqli->error) {
            return $result;
        } else {
            var_dump($this->_mysqli->error);
            exit;
        }
    }

    public function runMultiQuery($sql) {
        $result = $this->_mysqli->multi_query($sql);
        if (!$this->_mysqli->error) {
            return $result;
        } else {
            var_dump($this->_mysqli->error);
            exit;
        }
    }

    public function countRows($result) {
        return $result->num_rows;
    }

    public function fetchRows($result) {
        return $result->fetch_assoc();
    }

    public function getLastInsertedID() {
        return $this->_mysqli->insert_id;
    }

}