class User
	{
		public static function checkUser($password, $passwordDb, $username)
		{
			global $dbh;
			if (substr($passwordDb, 0, 1) == "$")
			{
				if (password_verify($password, $passwordDb))
				{
					return true;
				}
				return false;
			}
			else
			{
				$passwordBcrypt = self::hashed($password);
				if (md5($password) == $passwordDb)
				{
					$stmt = $dbh->prepare("UPDATE users SET password = :password WHERE username = :username");
					$stmt->bindParam(':username', $username);
					$stmt->bindParam(':password', $passwordBcrypt);
					$stmt->execute();
					return true;
				}
				return false;
			}
		}
		public static function hashed($password)
		{
			return password_hash($password, PASSWORD_BCRYPT);
		}
		public static function validName($username)
		{
			if(strlen($username) <= 12 && strlen($username) >= 3 && ctype_alnum($username))
			{
				return true;
			}
			return false;