import { getDate, getMonth, getYear, isValid, set } from "date-fns";
/**
 * Updates the date part (year, day and month) of a date object (base)
 * time, offset (timezone) and so on will be left untouched.
 *
 * @param  base - Date which will be used (copied) to set day, month and year.
 * @param  date - Extract day, month and year from this date object.
 * @returns Copy of base with day, month and year of date.
 */
export default (base: Date, date: Date | null) => {
  // ignore falsy dates
  if (date) {
    // allow invalid base and set time to 0
    base = isValid(base) ? base : new Date(Date.UTC(0, 0));
    return set(base, {
      year: getYear(date),
      month: getMonth(date),
      date: getDate(date),
    });
  }

  return base;
};