subtract method

FhirTime subtract({ int hours = 0, int minutes = 0, int seconds = 0, int milliseconds = 0, })

Implementation

FhirTime subtract(
    {int hours = 0, int minutes = 0, int seconds = 0, int milliseconds = 0}) {
  int newMilliseconds = (millisecond ?? 0) - milliseconds;
  int newSeconds = (second ?? 0) - seconds;
  int newMinutes = (minute ?? 0) - minutes;
  int newHours = (hour ?? 0) - hours;

  // Handle underflow for milliseconds
  while (newMilliseconds < 0) {
    newMilliseconds += 1000;
    newSeconds--;
  }

  // Handle underflow for seconds
  while (newSeconds < 0) {
    newSeconds += 60;
    newMinutes--;
  }

  // Handle underflow for minutes
  while (newMinutes < 0) {
    newMinutes += 60;
    newHours--;
  }

  // Handle underflow for hours
  while (newHours < 0) {
    newHours += 24;
  }
  newHours = newHours % 24; // Ensure hours wrap around a 24-hour clock

  return FhirTime.fromUnits(
    hour: newHours,
    minute: newMinutes,
    second: newSeconds,
    millisecond: newMilliseconds,
  );
}