/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

package java.util.concurrent;

/**
 * GWT emulation of TimeUnit, created by removing unsupported operations from
 * Doug Lea's public domain version.
 */
public enum TimeUnit {
  NANOSECONDS {
    public long toNanos(long d)   { return d; }
    public long toMicros(long d)  { return d/(C1/C0); }
    public long toMillis(long d)  { return d/(C2/C0); }
    public long toSeconds(long d) { return d/(C3/C0); }
    public long toMinutes(long d) { return d/(C4/C0); }
    public long toHours(long d)   { return d/(C5/C0); }
    public long toDays(long d)    { return d/(C6/C0); }
    public long convert(long d, TimeUnit u) { return u.toNanos(d); }
    int excessNanos(long d, long m) { return (int)(d - (m*C2)); }
  },
  MICROSECONDS {
    public long toNanos(long d)   { return x(d, C1/C0, MAX/(C1/C0)); }
    public long toMicros(long d)  { return d; }
    public long toMillis(long d)  { return d/(C2/C1); }
    public long toSeconds(long d) { return d/(C3/C1); }
    public long toMinutes(long d) { return d/(C4/C1); }
    public long toHours(long d)   { return d/(C5/C1); }
    public long toDays(long d)    { return d/(C6/C1); }
    public long convert(long d, TimeUnit u) { return u.toMicros(d); }
    int excessNanos(long d, long m) { return (int)((d*C1) - (m*C2)); }
  },
  MILLISECONDS {
    public long toNanos(long d)   { return x(d, C2/C0, MAX/(C2/C0)); }
    public long toMicros(long d)  { return x(d, C2/C1, MAX/(C2/C1)); }
    public long toMillis(long d)  { return d; }
    public long toSeconds(long d) { return d/(C3/C2); }
    public long toMinutes(long d) { return d/(C4/C2); }
    public long toHours(long d)   { return d/(C5/C2); }
    public long toDays(long d)    { return d/(C6/C2); }
    public long convert(long d, TimeUnit u) { return u.toMillis(d); }
    int excessNanos(long d, long m) { return 0; }
  },
  SECONDS {
    public long toNanos(long d)   { return x(d, C3/C0, MAX/(C3/C0)); }
    public long toMicros(long d)  { return x(d, C3/C1, MAX/(C3/C1)); }
    public long toMillis(long d)  { return x(d, C3/C2, MAX/(C3/C2)); }
    public long toSeconds(long d) { return d; }
    public long toMinutes(long d) { return d/(C4/C3); }
    public long toHours(long d)   { return d/(C5/C3); }
    public long toDays(long d)    { return d/(C6/C3); }
    public long convert(long d, TimeUnit u) { return u.toSeconds(d); }
    int excessNanos(long d, long m) { return 0; }
  },
  MINUTES {
    public long toNanos(long d)   { return x(d, C4/C0, MAX/(C4/C0)); }
    public long toMicros(long d)  { return x(d, C4/C1, MAX/(C4/C1)); }
    public long toMillis(long d)  { return x(d, C4/C2, MAX/(C4/C2)); }
    public long toSeconds(long d) { return x(d, C4/C3, MAX/(C4/C3)); }
    public long toMinutes(long d) { return d; }
    public long toHours(long d)   { return d/(C5/C4); }
    public long toDays(long d)    { return d/(C6/C4); }
    public long convert(long d, TimeUnit u) { return u.toMinutes(d); }
    int excessNanos(long d, long m) { return 0; }
  },
  HOURS {
    public long toNanos(long d)   { return x(d, C5/C0, MAX/(C5/C0)); }
    public long toMicros(long d)  { return x(d, C5/C1, MAX/(C5/C1)); }
    public long toMillis(long d)  { return x(d, C5/C2, MAX/(C5/C2)); }
    public long toSeconds(long d) { return x(d, C5/C3, MAX/(C5/C3)); }
    public long toMinutes(long d) { return x(d, C5/C4, MAX/(C5/C4)); }
    public long toHours(long d)   { return d; }
    public long toDays(long d)    { return d/(C6/C5); }
    public long convert(long d, TimeUnit u) { return u.toHours(d); }
    int excessNanos(long d, long m) { return 0; }
  },
  DAYS {
    public long toNanos(long d)   { return x(d, C6/C0, MAX/(C6/C0)); }
    public long toMicros(long d)  { return x(d, C6/C1, MAX/(C6/C1)); }
    public long toMillis(long d)  { return x(d, C6/C2, MAX/(C6/C2)); }
    public long toSeconds(long d) { return x(d, C6/C3, MAX/(C6/C3)); }
    public long toMinutes(long d) { return x(d, C6/C4, MAX/(C6/C4)); }
    public long toHours(long d)   { return x(d, C6/C5, MAX/(C6/C5)); }
    public long toDays(long d)    { return d; }
    public long convert(long d, TimeUnit u) { return u.toDays(d); }
    int excessNanos(long d, long m) { return 0; }
  };

  // Handy constants for conversion methods
  static final long C0 = 1L;
  static final long C1 = C0 * 1000L;
  static final long C2 = C1 * 1000L;
  static final long C3 = C2 * 1000L;
  static final long C4 = C3 * 60L;
  static final long C5 = C4 * 60L;
  static final long C6 = C5 * 24L;

  static final long MAX = Long.MAX_VALUE;

  static long x(long d, long m, long over) {
    if (d >  over) return Long.MAX_VALUE;
    if (d < -over) return Long.MIN_VALUE;
    return d * m;
  }

  // exceptions below changed from AbstractMethodError for GWT

  public long convert(long sourceDuration, TimeUnit sourceUnit) {
    throw new AssertionError();
  }

  public long toNanos(long duration) {
    throw new AssertionError();
  }

  public long toMicros(long duration) {
    throw new AssertionError();
  }

  public long toMillis(long duration) {
    throw new AssertionError();
  }

  public long toSeconds(long duration) {
    throw new AssertionError();
  }

  public long toMinutes(long duration) {
    throw new AssertionError();
  }

  public long toHours(long duration) {
    throw new AssertionError();
  }

  public long toDays(long duration) {
    throw new AssertionError();
  }

  abstract int excessNanos(long d, long m);
}