EventBuilder::prepareReminderValue

private function prepareReminderValue(
	Remind $remind,
	bool $isFullDay
): array
{
	$valueType = '';
	$value = '';

	if ($remind->getUnits() === 'minutes')
	{
		$valueType = 'DURATION';
		if ($remind->getTime() === 60 || $remind->getTime() === 120)
		{
			$value = '-PT' . $remind->getTime() / 60 . 'H';
		}
		else if ($remind->getTime() === 0)
		{
			$value = 'PT' . $remind->getTime() . 'S';
		}
		else
		{
			$value = '-PT' . $remind->getTime() . 'M';
		}
	}
	else if ($remind->getSpecificTime() && $remind->getDaysBefore() !== null)
	{
		$valueType = 'DURATION';
		$diff = $remind->getTimeBeforeStartInMinutes();
		$parsedDiff = Util::minutesToDayHoursMinutes(abs($diff));
		if ($isFullDay  && $remind->getDaysBefore() === 0)
		{
			$value = 'PT' . $parsedDiff['hours'] . 'H';
		}
		else if (
			($remind->getDaysBefore() === 0 && !$isFullDay && $diff > 0)
			|| ($remind->getDaysBefore() === 1 && $parsedDiff['days'] === 0)
		)
		{
			$hours = '';
			$minutes = '';
			if ($parsedDiff['hours'])
			{
				$hours = $parsedDiff['hours'] . 'H';
			}
			if ($parsedDiff['minutes'])
			{
				$minutes = $parsedDiff['minutes'] . 'M';
			}
			$value = '-PT' . $hours . $minutes;
		}
		else if ($parsedDiff['days'] > 0)
		{
			$hours = '';
			$minutes = '';
			$value = '-P' . $parsedDiff['days'] . 'D';
			if ($parsedDiff['hours'])
			{
				$hours = $parsedDiff['hours'] . 'H';
			}
			if ($parsedDiff['minutes'])
			{
				$minutes = $parsedDiff['minutes'] . 'M';
			}
			if ($hours || $minutes)
			{
				$value .= 'T' . $hours . $minutes;
			}
		}
		else
		{
			return [null, null];
		}
	}
	else if ($remind->getSpecificTime())
	{
		$valueType = 'DATE-TIME';
		$value = date('Ymd\THis\Z', $remind->getSpecificTime()->getTimestamp());
	}

	return [$value, $valueType];
}