content: /**
   * 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.bigtop.datagenerators.bigpetstore.generators.transaction;
  
  import java.util.List;
  
  import org.apache.commons.lang3.tuple.Pair;
  
  import com.google.common.collect.Lists;
  
  public class ProductCategoryUsageTrajectory
  {
  	final private List<Pair<Double, Double>> trajectory;
  
  	public ProductCategoryUsageTrajectory(double initialTime, double initialAmount)
  	{
  		trajectory = Lists.newArrayList();
  		this.append(initialTime, initialAmount);
  	}
  
  	public void append(double time, double amount)
  	{
  		trajectory.add(Pair.of(time, amount));
  	}
  
  	public double getLastAmount()
  	{
  		return trajectory.get(trajectory.size() - 1).getValue();
  	}
  
  	public double getLastTime()
  	{
  		return trajectory.get(trajectory.size() - 1).getKey();
  	}
  
  	public double amountAtTime(double time)
  	{
  		Pair<Double, Double> previous = null;
  		for(Pair<Double, Double> entry : trajectory)
  		{
  			if(entry.getKey() > time)
  				break;
  			previous = entry;
  		}
  
  		if(previous == null)
  			return 0.0;
  
  		return previous.getValue();
  	}
  
  	public Pair<Double, Double> getStep(int idx)
  	{
  		return trajectory.get(idx);
  	}
  
  	public int size()
  	{
  		return trajectory.size();
  	}
  }
  