/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.apex.benchmark;

import javax.validation.constraints.Min;

import com.datatorrent.api.Context.OperatorContext;

import com.datatorrent.api.DefaultOutputPort;
import com.datatorrent.api.InputOperator;

/**
 * <p>
 * RandomWordInputModule class.
 * </p>
 *
 * @since 0.3.2
 */
public class RandomWordInputModule implements InputOperator
{
  public final transient DefaultOutputPort<byte[]> output = new DefaultOutputPort<byte[]>();
  private transient int count;
  private boolean firstTime;

  private boolean emitSameTuple = false;
  byte[] sameTupleArray;

  @Min(1)
  private int tupleSize = 64;

  /**
   * Sets the size of the tuple to the specified size. The change to tuple size takes effect in next window.
   *
   * @param size
   *          the tupleSize to set
   */
  public void setTupleSize(int size)
  {
    tupleSize = size;
    if (emitSameTuple) {
      sameTupleArray = new byte[tupleSize];
    }
  }

  /**
   * @return the tupleSize
   */
  public int getTupleSize()
  {
    return tupleSize;
  }

  /**
   * Sets the property that decides if the operator emits same tuple or creates new tuple for every emit. The change
   * takes effect in next window.
   *
   * @param isSameTuple
   *          the boolean value to set for 'emitSameTuple' property
   */
  public void setEmitSameTuple(boolean isSameTuple)
  {
    emitSameTuple = isSameTuple;
    if (isSameTuple) {
      sameTupleArray = new byte[tupleSize];
    }
  }

  /**
   * @return the emitSameTuple property
   */
  public boolean getEmitSameTuple()
  {
    return emitSameTuple;
  }

  /**
   * Emits byte array of specified size.
   * Emits either the same byte array or creates new byte array every time
   * depending on the value of emitSameTuple property.
   * Local copies of tupleSize and emitSameTuple are made to improve the
   * performance.
   *
   */
  @Override
  public void emitTuples()
  {
    final int TUPLE_SIZE_COPY = tupleSize;
    final boolean EMIT_SAME_TUPLE_COPY = emitSameTuple;
    if (firstTime) {
      if (EMIT_SAME_TUPLE_COPY) {
        for (int i = count--; i-- > 0; ) {
          output.emit(sameTupleArray);
        }
      } else {
        for (int i = count--; i-- > 0; ) {
          output.emit(new byte[TUPLE_SIZE_COPY]);
        }
      }
      firstTime = false;
    } else {
      if (EMIT_SAME_TUPLE_COPY) {
        output.emit(sameTupleArray);
      } else {
        output.emit(new byte[TUPLE_SIZE_COPY]);
      }
      count++;
    }
  }

  @Override
  public void beginWindow(long windowId)
  {
    firstTime = true;
  }

  @Override
  public void endWindow()
  {
  }

  @Override
  public void setup(OperatorContext context)
  {
  }

  @Override
  public void teardown()
  {
  }

}
