import { normalizeUnits } from ‘../units/aliases’;

export function startOf (units) {

units = normalizeUnits(units);
// the following switch intentionally omits break keywords
// to utilize falling through the cases.
switch (units) {
case 'year':
    this.month(0);
    /* falls through */
case 'quarter':
case 'month':
    this.date(1);
    /* falls through */
case 'week':
case 'isoWeek':
case 'day':
    this.hours(0);
    /* falls through */
case 'hour':
    this.minutes(0);
    /* falls through */
case 'minute':
    this.seconds(0);
    /* falls through */
case 'second':
    this.milliseconds(0);
}

// weeks are a special case
if (units === 'week') {
    this.weekday(0);
}
if (units === 'isoWeek') {
    this.isoWeekday(1);
}

// quarters are also special
if (units === 'quarter') {
    this.month(Math.floor(this.month() / 3) * 3);
}

return this;

}

export function endOf (units) {

units = normalizeUnits(units);
if (units === undefined || units === 'millisecond') {
    return this;
}
return this.startOf(units).add(1, (units === 'isoWeek' ? 'week' : units)).subtract(1, 'ms');

}