import toInteger from '../_lib/toInteger/index.js'
import addDays from '../addDays/index.js'

/**
 * @name subDays
 * @category Day Helpers
 * @summary Subtract the specified number of days from the given date.
 *
 * @description
 * Subtract the specified number of days from the given date.
 *
 *
 * ### v2.0.0 breaking changes:
 *
 * - [Changes that are common for the whole library](https://github.com/date-fns/date-fns/blob/master/docs/upgradeGuide.md#Common-Changes).
 *
 * @param {Date|String|Number} date - the date to be changed
 * @param {Number} amount - the amount of days to be subtracted
 * @param {Options} [options] - the object with options. See [Options]{@link https://date-fns.org/docs/Options}
 * @param {0|1|2} [options.additionalDigits=2] - passed to `toDate`. See [toDate]{@link https://date-fns.org/docs/toDate}
 * @returns {Date} the new date with the days subtracted
 * @throws {TypeError} 2 arguments required
 * @throws {RangeError} `options.additionalDigits` must be 0, 1 or 2
 *
 * @example
 * // Subtract 10 days from 1 September 2014:
 * var result = subDays(new Date(2014, 8, 1), 10)
 * //=> Fri Aug 22 2014 00:00:00
 */
export default function subDays (dirtyDate, dirtyAmount, dirtyOptions) {
  if (arguments.length < 2) {
    throw new TypeError('2 arguments required, but only ' + arguments.length + ' present')
  }

  var amount = toInteger(dirtyAmount)
  return addDays(dirtyDate, -amount, dirtyOptions)
}
