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/*
 * Copyright (c) 2001-2017, Zoltan Farkas All Rights Reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * Additionally licensed with:
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.spf4j.failsafe;

import org.spf4j.failsafe.avro.TimeoutRelativeHedgePolicy;

/**
 * @author Zoltan Farkas
 */
public final class TimeoutRelativeHedge implements HedgePolicy {

  private final double timeoutHedgeFactor;

  private final long minHedgeDelay;

  private final long maxHedgeDelay;

  private final int nrHedges;

  public TimeoutRelativeHedge(final int timeoutHedgeFraction, final long minHedgeDelayNanos,
          final long maxHedgeDelayNanos, final int nrHedges) {
    if (minHedgeDelayNanos > maxHedgeDelayNanos) {
      throw new IllegalArgumentException("Min hedge delay " + minHedgeDelayNanos
              + " greater than maxHedgeDelay " + maxHedgeDelayNanos);
    }
    this.timeoutHedgeFactor = ((double) 1) / timeoutHedgeFraction;
    this.minHedgeDelay = minHedgeDelayNanos;
    this.maxHedgeDelay = maxHedgeDelayNanos;
    this.nrHedges = nrHedges;
  }

  public TimeoutRelativeHedge(final TimeoutRelativeHedgePolicy hp) {
    this.timeoutHedgeFactor = hp.getFactor();
    this.minHedgeDelay = hp.getMinHedgeDelay().toNanos();
    this.maxHedgeDelay = hp.getMaxHedgeDelay().toNanos();
    this.nrHedges = hp.getNrHedges();
  }



  @Override
  public Hedge getHedge(final long startTimeNanos, final long deadlineNanos) {
    long timeoutNanos = deadlineNanos - startTimeNanos;
    if (minHedgeDelay >= timeoutNanos) {
      return Hedge.NONE;
    }
    long hedgeDelay = (long) (timeoutNanos * timeoutHedgeFactor);

    if (hedgeDelay <  minHedgeDelay) {
      return new Hedge(minHedgeDelay, nrHedges);
    } else if (hedgeDelay > maxHedgeDelay) {
      return new Hedge(maxHedgeDelay, nrHedges);
    } else {
      return new Hedge(hedgeDelay, nrHedges);
    }
  }

  @Override
  public String toString() {
    return "TimeoutRelativeHedge{" + "timeoutHedgeFactor=" + timeoutHedgeFactor
            + ", minHedgeDelay=" + minHedgeDelay + ", maxHedgeDelay=" + maxHedgeDelay + ", nrHedges=" + nrHedges + '}';
  }



}