PHP Database connection

database.php

    /*
    Copyright © 2016 CrazyDev
    
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
    
    */
<?php

	class Database {
		
		private $host = "localhost";
		private $username = "root";
		private $password = "root";
		private $database = "test";
		
		private $connection;
		
		public function Database() {
			if(func_num_args() > 0) {
				call_user_func_array(array($this, "setFields"), func_get_args());
			}
			$this->getMyConnection();
			if ($this->connection->connect_errno) {
				echo 'Falied to connect mysqli, error: '.$this->connection->connect_error;
			} 
		}
		
		public function getMyConnection() {
			if(!isset($this->connection)) {
				$this->connection = $this->getNewConnection();
			}
			return $this->connection;
		}
		
		public function getNewConnection() {
			if(isset($this->host) || isset($this->username) || isset($this->password) || isset($this->database)) {
				return new mysqli($this->host, $this->username, $this->password, $this->database) or die('Could not connect to server.' );
			}
		}
		
		
		public function cleanUpDB() {
			if(!isset($this->connection)) {
				$this->closeDatabase($this->connection);
			}
		}
		
		public function closeDatabase($connection) {
			if(isset($connection) && $connection instanceof mysqli) {
				mysqli_close($connection) or die($connection->error);
			}
		}
		
		public function setFields($host, $username, $password, $database) {
			$this->host = $host;
			$this->username = $username;
			$this->password = $password;
			$this->database = $database;
		}
		
	}
?>