Method getCurrency

/*public static function getCurrency() {

		if(self::$currency === false){
			$session 		= Factory::getSession();
			$currencyId		= $session->get('currency', 0, 'phocaCart');
			if ((int)$currencyId < 1) {
				$currencyId = self::getDefaultCurrency();
			}

			$db = Factory::getDBO();
			$query = ' SELECT a.* FROM #__phocacart_currencies AS a'
					.' WHERE a.id = '.(int)$currencyId;
			$db->setQuery($query);
			$c = $db->loadObject();

			if (!empty($c)) {
				self::$currency = $c;
			} else {
				self::$currency = false;
			}
		}
		return self::$currency;
	}*/
public static function getCurrency($id = 0, $orderId = 0)
{
    // Order currency is never stored in session
    // so we use id instead of key
    $session = Factory::getSession();
    if ($id == 0) {
        $id = $session->get('currency', 0, 'phocaCart');
        // check only session currencies, not database - as they can be order currencies
        $isValid = self::isCurrencyValid($id);
        if (!$isValid) {
            $id = 0;
        }
    }
    if ((int) $id < 1) {
        $id = self::getDefaultCurrency();
        $session->set('currency', (int) $id, 'phocaCart');
    }
    $id = (int) $id;
    // Price can be different for each currency and order
    // So there is a key which identifies default currency, other currency, default currency in order, other currency in order
    // one currency can have different exchange rates in order history, so two orders can have same currency but different exchange rate
    $key = base64_encode(serialize((int) $id . ':' . (int) $orderId));
    if (!array_key_exists((string) $key, self::$currency)) {
        $db = Factory::getDBO();
        $query = ' SELECT a.* FROM #__phocacart_currencies AS a' . ' WHERE a.id = ' . (int) $id . ' ORDER BY a.id';
        $db->setQuery($query);
        $c = $db->loadObject();
        if (!empty($c)) {
            self::$currency[$key] = $c;
        } else {
            self::$currency[$key] = false;
        }
    }
    return self::$currency[$key];
}