import jlibs.core.lang;

// we want to count the time
Count<DurationUnit> duration = Count.newInstance(DurationUnit.class);

// additions
duration.add(500, DurationUnit.SECONDS);
System.out.println(duration); // prints "8 MINUTES 20 SECONDS"
duration.add(100, DurationUnit.MINUTES);
System.out.println(duration); // prints "1 HOURS 48 MINUTES 20 SECONDS"

// get specific unit value
System.out.println(duration.get(DurationUnit.MINUTES); // prints "48"
System.out.println(duration.get(DurationUnit.SECONDS); // prints "20"

// conversions
System.out.println(duration.to(DurationUnit.SECONDS)); // prints "6500.0"
System.out.println(duration.to(DurationUnit.MINUTES)); // prints "108.33333333333333"

// reset to given value
duration.set(500, DurationUnit.SECONDS);
System.out.println(duration); // prints "8 MINUTES 20 SECONDS"

// reset to 0
duration.clear();
System.out.println(duration); // prints "0 NANO_SECONDS"

// adding two counts
Count<DurationUnit> duration1 = Count.newInstance(DurationUnit.class);
duration1.add(500, DurationUnit.SECONDS);
Count<DurationUnit> duration2 = Count.newInstance(DurationUnit.class);
duration2.add(100, DurationUnit.MINUTES);
duration1.add(duration2);
System.out.println(duration1); // prints "1 HOURS 48 MINUTES 20 SECONDS"

// you can count by any unit, for example
Count<SizeUnit> size = Count.newInstance(SizeUnit.class);
size.add(5000, SizeUnit.BYTES);
System.out.println(size); // prints "4 KB 904 BYTES"

public enum LengthUnit implements Count.Unit{
    MILLI_METERS(10), CENTI_METERS(100), METERS(1000), KILO_METERS(0);

    private int count;

    private DurationUnit(int count){
        this.count = count;
    }

    @Override
    public int count(){
        return count;
    }
}

Count<LengthUnit> size = Count.newInstance(LengthUnit.class);