import java.time.*;
import java.time.temporal.*;
import java.util.*;
import java.util.concurrent.TimeUnit;
import java.nio.file.attribute.FileTime;

public class TestFileTime {

    public static void main(String[] args) throws Throwable {
        test(20000, TimeUnit.SECONDS,      2000000);
        test(20000, TimeUnit.MILLISECONDS, 2000000);
        test(20000, TimeUnit.MILLISECONDS, 2000);
        test(20000, TimeUnit.NANOSECONDS,  200);
        //testExtra(20000);
    }

    private static void test(int N, TimeUnit UNIT, int year) {
        final int NANOS_PER_SECOND = 1000_000_000;
        Random r = new Random();

        for (int i = 0; i < N; i++) {
            long years  = r.nextInt(year);
            long days  = (years * 365L + r.nextInt(365)) * (r.nextBoolean()? 1 : -1);
            long secs = days * 86400L + r.nextInt(86400);
            long millis = secs * 1000 + r.nextInt(1000);
            int  nanosPerSec = r.nextInt(NANOS_PER_SECOND);

            long VALUE = 0L;
            if (UNIT == TimeUnit.SECONDS) {
                VALUE = secs;
            } else if (UNIT == TimeUnit.MILLISECONDS) {
                VALUE = millis;
            } else if (UNIT == TimeUnit.NANOSECONDS) {
                VALUE = secs * NANOS_PER_SECOND + nanosPerSec;
            } else {
                return;
            }
            for (TimeUnit unit : EnumSet.allOf(TimeUnit.class)) {
                long value = unit.convert(VALUE, UNIT);
                FileTime ft = FileTime.from(value, unit);
                FileTimeOLD ftOLD = FileTimeOLD.from(value, unit);
                if (!ft.toString().equals(ftOLD.toString())) {
                    System.out.println("NEW: [" + ft.toString() + "]");
                    System.out.println("OLD: [" + ftOLD.toString() + "]");
                    throw new RuntimeException("FAILED");
                }
            }
            if (UNIT == TimeUnit.NANOSECONDS) {
                FileTimeOLD ftOLD = FileTimeOLD.from(VALUE, UNIT);
                Instant ins = Instant.ofEpochSecond(secs, nanosPerSec);
                FileTime ft = FileTime.from(ins);
                if (!ft.toString().equals(ftOLD.toString())) {
                    System.out.println("-------------------------------");
                    System.out.println(" years=" + years);
                    System.out.println("  days=" + days);
                    System.out.println("  secs=" + secs);
                    System.out.println("millis=" + millis);
                    System.out.println(" nanos=" + nanosPerSec);
                    System.out.println(" value=" + VALUE);
                    System.out.println(" ins.d=" + LocalDateTime.ofInstant(ins, ZoneOffset.UTC)
                                                                .getLong(ChronoField.EPOCH_DAY));
                    System.out.println(" ins.s=" + ins.getLong(ChronoField.INSTANT_SECONDS));
                    System.out.println(" ins.n=" + ins.getNano());
                    System.out.println("INS: " + ins);
                    System.out.println("NEW: " + ft);
                    System.out.println("OLD: " + ftOLD);
                    throw new RuntimeException("FAILED");
                }
            }
        }
    }

    private static void testExtra(int N) {
        Random r = new Random();
        for (TimeUnit unit : EnumSet.allOf(TimeUnit.class)) {
            if (unit.compareTo(TimeUnit.SECONDS) <= 0) {
                continue;
            }
            for (int i = 0; i < 10; i++) {
                long value = Math.abs(r.nextInt(1000_000_000)) +
                             unit.convert(Instant.MAX.getEpochSecond(),
                                          TimeUnit.SECONDS);
                FileTime ft = FileTime.from(value, unit);
                FileTimeOLD ftOLD = FileTimeOLD.from(value, unit);
                if (!ft.toString().equals(ftOLD.toString())) {
                    System.out.println("------------------------");
                    System.out.println("TestValue="  + value + ", unit=" + unit);
                    System.out.println("  NEW: [" + ft.toString() + "]");
                    System.out.println("  OLD: [" + ftOLD.toString() + "]");
                    //throw new RuntimeException("FAILED");
                }
            }
        }
    }

}