<?php

class MnbExchangeRate 
{
    public function currencyExchangeRate(string $currency = 'EUR'): float
    {

        $client = new SoapClient("http://www.mnb.hu/arfolyamok.asmx?wsdl");
        $response = $client->__soapCall("GetCurrentExchangeRates", []);

        $doc = new DOMDocument;
        $doc->loadXML($response->GetCurrentExchangeRatesResult);
        $xpath = new DOMXPath($doc);

        $query = "//MNBCurrentExchangeRates/Day/Rate[@curr='$currency']";
        $entries = $xpath->query($query);

        return ($entries->length) ? (float) str_replace(',', '.', $entries->item(0)->nodeValue) : 0;        
    }
}