/**
* Note in some regions, the national number can be written in two completely different ways
* depending on whether it forms part of the NATIONAL format or INTERNATIONAL format. The
* numberFormat parameter here is used to specify which format to use for those cases. If a
* carrierCode is specified, this will be inserted into the formatted string to replace $CC.
* @param string $number
* @param PhoneMetadata $metadata
* @param int $numberFormat PhoneNumberFormat
* @param null|string $carrierCode
* @return string
*/
private function formatNsn($number, PhoneMetadata $metadata, $numberFormat, $carrierCode = null)
{
$intlNumberFormats = $metadata->intlNumberFormats();
// When the intlNumberFormats exists, we use that to format national number for the
// INTERNATIONAL format instead of using the numberDesc.numberFormats.
$availableFormats = count($intlNumberFormats) == 0 || $numberFormat == PhoneNumberFormat::NATIONAL ? $metadata->numberFormats() : $metadata->intlNumberFormats();
$formattingPattern = $this->chooseFormattingPatternForNumber($availableFormats, $number);
return $formattingPattern === null ? $number : $this->formatNsnUsingPattern($number, $formattingPattern, $numberFormat, $carrierCode);
}