import { toInt } from '../utils/type-checks';
import { createDuration } from './create';
import { Duration } from './constructor';
import { DateObject } from '../types';

const ordering: (keyof DateObject)[] = ['year', 'quarter', 'month', 'week', 'day', 'hours', 'minutes', 'seconds', 'milliseconds'];
const orderingHash = ordering.reduce((mem: { [key: string]: boolean }, order) => {
  mem[order] = true;

  return mem;
}, {});

export function isDurationValid(duration: Partial<DateObject>): boolean {
  const durationKeys = Object.keys(duration);
  if (durationKeys
      .some((key: keyof DateObject) => {
        return (key in orderingHash)
          && duration[key] === null
          || isNaN(duration[key]);
      })) {
    return false;
  }
  // for (let key in duration) {
  //   if (!(indexOf.call(ordering, key) !== -1 && (duration[key] == null || !isNaN(duration[key])))) {
  //     return false;
  //   }
  // }

  let unitHasDecimal = false;
  for (let i = 0; i < ordering.length; ++i) {
    if (duration[ordering[i]]) {
      // only allow non-integers for smallest unit
      if (unitHasDecimal) {
        return false;
      }
      if (duration[ordering[i]] !== toInt(duration[ordering[i]])) {
        unitHasDecimal = true;
      }
    }
  }

  return true;
}

// export function isValid() {
//   return this._isValid;
// }
//
// export function createInvalid(): Duration {
//   return createDuration(NaN);
// }