import { UnitOfTime } from '../types';
import { endOf, startOf } from './start-end-of';

export function isAfter(date1: Date, date2: Date, units: UnitOfTime = 'milliseconds'): boolean {
  if (!date1 || !date2) {
    return false;
  }

  if (units === 'milliseconds') {
    return date1.valueOf() > date2.valueOf();
  }

  return date2.valueOf() < startOf(date1, units).valueOf();
}

export function isBefore(date1: Date, date2: Date, units: UnitOfTime = 'milliseconds'): boolean {
  if (!date1 || !date2) {
    return false;
  }

  if (units === 'milliseconds') {
    return date1.valueOf() < date2.valueOf();
  }

  return endOf(date1, units).valueOf() < date2.valueOf();
}

export function isBetween(date: Date,
                          from: Date,
                          to: Date,
                          units: UnitOfTime,
                          inclusivity = '()'): boolean {
  const leftBound = inclusivity[0] === '('
    ? isAfter(date, from, units) :
    !isBefore(date, from, units);
  const rightBound = inclusivity[1] === ')'
    ? isBefore(date, to, units)
    : !isAfter(date, to, units);

  return leftBound && rightBound;
}

export function isSame(date1: Date, date2: Date, units: UnitOfTime = 'milliseconds'): boolean {
  if (!date1 || !date2) {
    return false;
  }

  if (units === 'milliseconds') {
    return date1.valueOf() === date2.valueOf();
  }

  const inputMs = date2.valueOf();

  return startOf(date1, units).valueOf() <= inputMs
    && inputMs <= endOf(date1, units).valueOf();
}

export function isSameOrAfter(date1: Date, date2: Date, units?: UnitOfTime): boolean {
  return isSame(date1, date2, units) || isAfter(date1, date2, units);
}

export function isSameOrBefore(date1: Date, date2: Date, units?: UnitOfTime): boolean {
  return isSame(date1, date2, units) || isBefore(date1, date2, units);
}