<?php

final class MySQL
{
    private static $instance;

    public $db_count = 0;

    public $db_link;

    private function __construct()
    {
        $this->db_link = new mysqli(BD_HOST, BD_USER, BD_PASS, BD_NAME, 3306);

        if ($this->db_link->connect_error) {
            exit();
        }

        $this->db_link->set_charset("utf8");
    }

    public static function getInstance()
    {
        if (self::$instance === null) {
            self::$instance = new self();
        }

        return self::$instance;
    }

    public function query($sql)
    {
        $query = $this->db_link->query($sql);

        $this->db_count += 1;

        if ($this->db_link->error) {
            exit($this->db_link->error);
        }

        return $query;
    }

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

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

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

    public function __destruct()
    {
        $this->db_link->close();
    }
}

?>