using System;

namespace Mk0.Tools.TimeTools
{
    public static class TimeTools
    {
        public static DateTime RoundUp(this DateTime dt, TimeSpan d)
        {
            var modTicks = dt.Ticks % d.Ticks;
            var delta = modTicks != 0 ? d.Ticks - modTicks : 0;
            return new DateTime(dt.Ticks + delta, dt.Kind);
        }

        public static DateTime RoundDown(this DateTime dt, TimeSpan d)
        {
            var delta = dt.Ticks % d.Ticks;
            return new DateTime(dt.Ticks - delta, dt.Kind);
        }

        public static DateTime RoundToNearest(this DateTime dt, TimeSpan d)
        {
            var delta = dt.Ticks % d.Ticks;
            bool roundUp = delta > d.Ticks / 2;
            var offset = roundUp ? d.Ticks : 0;

            return new DateTime(dt.Ticks + offset - delta, dt.Kind);
        }
    }
}