<?php

/**
 * Created by PhpStorm.
 * User: Nermin
 * Date: 28. 05. 2018
 * Time: 12:12
 */

class DBconnect {

    private static $host = "localhost";
    private static $user = "nermin";
    private static $password = "";
    private static $schema = "dialectsdb";
    private static $instance = null;

    private function __construct() {

    }

    private function __clone() {

    }

    /**
     * Returns a PDO instance -- a connection to the database.
     * The singleton instance assures that there is only one connection active
     * at once (within the scope of one HTTP request)
     *
     * @return PDO instance
     */
    public static function getInstance() {

        // Check for config overrides via enviroment variables.
        if (getenv('DB_HOST')) {
            self::$host = getenv('DB_HOST');
        }
        if (getenv('DB_USER')) {
            self::$user = getenv('DB_USER');
        }
        if (getenv('DB_PASS')) {
            self::$password = getenv('DB_PASS');
        }
        if (getenv('DB_SCHEMA')) {
            self::$schema = getenv('DB_SCHEMA');
        }

        if (!self::$instance) {
            $config = "mysql:host=" . self::$host
                . ";dbname=" . self::$schema;
            $options = array(
                PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
                PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
                PDO::ATTR_PERSISTENT => true,
                PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8'
            );

            self::$instance = new PDO($config, self::$user, self::$password, $options);
        }

        return self::$instance;
    }

}