import type { Duration } from './types';

function duration(amount: number, unit: Duration['unit']): Duration {
  if (!Number.isFinite(amount) || amount < 0) {
    throw new Error('Duration amount must be a non-negative finite number.');
  }
  return { kind: 'duration', amount, unit };
}

export function weeks(amount: number): Duration {
  return duration(amount, 'WEEKS');
}

export function days(amount: number): Duration {
  return duration(amount, 'DAYS');
}

export function hours(amount: number): Duration {
  return duration(amount, 'HOURS');
}