class PhpTimeConverter

class PhpTimeConverter implements TimeConverterInterface {
    
    /**
     * The number of 100-nanosecond intervals from the Gregorian calendar epoch
     * to the Unix epoch.
     */
    private const GREGORIAN_TO_UNIX_INTERVALS = 0x1b21dd213814000;
    
    /**
     * The number of 100-nanosecond intervals in one second.
     */
    private const SECOND_INTERVALS = 10000000;
    
    /**
     * The number of 100-nanosecond intervals in one microsecond.
     */
    private const MICROSECOND_INTERVALS = 10;
    private int $phpPrecision;
    private CalculatorInterface $calculator;
    private TimeConverterInterface $fallbackConverter;
    public function __construct(?CalculatorInterface $calculator = null, ?TimeConverterInterface $fallbackConverter = null) {
        if ($calculator === null) {
            $calculator = new BrickMathCalculator();
        }
        if ($fallbackConverter === null) {
            $fallbackConverter = new GenericTimeConverter($calculator);
        }
        $this->calculator = $calculator;
        $this->fallbackConverter = $fallbackConverter;
        $this->phpPrecision = (int) ini_get('precision');
    }
    public function calculateTime(string $seconds, string $microseconds) : Hexadecimal {
        $seconds = new IntegerObject($seconds);
        $microseconds = new IntegerObject($microseconds);
        // Calculate the count of 100-nanosecond intervals since the Gregorian
        // calendar epoch for the given seconds and microseconds.
        $uuidTime = (int) $seconds->toString() * self::SECOND_INTERVALS + (int) $microseconds->toString() * self::MICROSECOND_INTERVALS + self::GREGORIAN_TO_UNIX_INTERVALS;
        // Check to see whether we've overflowed the max/min integer size.
        // If so, we will default to a different time converter.
        
        /** @psalm-suppress RedundantCondition */
        if (!is_int($uuidTime)) {
            return $this->fallbackConverter
                ->calculateTime($seconds->toString(), $microseconds->toString());
        }
        return new Hexadecimal(str_pad(dechex($uuidTime), 16, '0', STR_PAD_LEFT));
    }
    public function convertTime(Hexadecimal $uuidTimestamp) : Time {
        $timestamp = $this->calculator
            ->toInteger($uuidTimestamp);
        // Convert the 100-nanosecond intervals into seconds and microseconds.
        $splitTime = $this->splitTime(((int) $timestamp->toString() - self::GREGORIAN_TO_UNIX_INTERVALS) / self::SECOND_INTERVALS);
        if (count($splitTime) === 0) {
            return $this->fallbackConverter
                ->convertTime($uuidTimestamp);
        }
        return new Time($splitTime['sec'], $splitTime['usec']);
    }
    
    /**
     * @param float|int $time The time to split into seconds and microseconds
     *
     * @return string[]
     */
    private function splitTime(float|int $time) : array {
        $split = explode('.', (string) $time, 2);
        // If the $time value is a float but $split only has 1 element, then the
        // float math was rounded up to the next second, so we want to return
        // an empty array to allow use of the fallback converter.
        if (is_float($time) && count($split) === 1) {
            return [];
        }
        if (count($split) === 1) {
            return [
                'sec' => $split[0],
                'usec' => '0',
            ];
        }
        // If the microseconds are less than six characters AND the length of
        // the number is greater than or equal to the PHP precision, then it's
        // possible that we lost some precision for the microseconds. Return an
        // empty array, so that we can choose to use the fallback converter.
        if (strlen($split[1]) < 6 && strlen((string) $time) >= $this->phpPrecision) {
            return [];
        }
        $microseconds = $split[1];
        // Ensure the microseconds are no longer than 6 digits. If they are,
        // truncate the number to the first 6 digits and round up, if needed.
        if (strlen($microseconds) > 6) {
            $roundingDigit = (int) substr($microseconds, 6, 1);
            $microseconds = (int) substr($microseconds, 0, 6);
            if ($roundingDigit >= 5) {
                $microseconds++;
            }
        }
        return [
            'sec' => $split[0],
            'usec' => str_pad((string) $microseconds, 6, '0', STR_PAD_RIGHT),
        ];
    }

}