// $Header: /home/cvs/jakarta-jmeter/src/functions/org/apache/jmeter/functions/IntSum.java,v 1.6 2004/02/10 00:35:12 sebb Exp $
/*
 * Copyright 2003-2004 The Apache Software Foundation.
 *
 * 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.apache.jmeter.functions;

import java.io.Serializable;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;

import org.apache.jmeter.engine.util.CompoundVariable;
import org.apache.jmeter.samplers.SampleResult;
import org.apache.jmeter.samplers.Sampler;
import org.apache.jmeter.threads.JMeterVariables;
import org.apache.jmeter.util.JMeterUtils;

/**
 * Provides an intSum function that adds two or more integer values.
 *
 * @author Scott Eade
 * @version $Id: IntSum.java,v 1.6 2004/02/10 00:35:12 sebb Exp $
 */
public class IntSum extends AbstractFunction implements Serializable
{

    private static final List desc = new LinkedList();
    private static final String KEY = "__intSum";

    static {
        desc.add(JMeterUtils.getResString("intsum_param_1"));
        desc.add(JMeterUtils.getResString("intsum_param_2"));
        desc.add(JMeterUtils.getResString("function_name_param"));
    }

    private Object[] values;

    /**
     * No-arg constructor.
     */
    public IntSum()
    {
    }

    /**
     * Clone this Add object.
     * 
     * @return A new Add object.
     */
    public Object clone()
    {
        IntSum newIntSum = new IntSum();
        return newIntSum;
    }

    /**
     * Execute the function.
     * 
     * @see Function#execute(SampleResult, Sampler)
     */
    public synchronized String execute(
        SampleResult previousResult,
        Sampler currentSampler)
        throws InvalidVariableException
    {

        JMeterVariables vars = getVariables();

        int sum = 0;
        String varName =
            ((CompoundVariable) values[values.length - 1]).execute();

        for (int i = 0; i < values.length - 1; i++)
        {
            sum += Integer.parseInt(((CompoundVariable) values[i]).execute());
        }

        String totalString = Integer.toString(sum);
        vars.put(varName, totalString);

        return totalString;

    }

    /**
     * Set the parameters for the function.
     * 
     * @see Function#setParameters(Collection)
     */
    public void setParameters(Collection parameters)
        throws InvalidVariableException
    {
        values = parameters.toArray();

        if (values.length < 3)
        {
            throw new InvalidVariableException();
        }

    }

    /**
     * Get the invocation key for this function.
     * 
     * @see Function#getReferenceKey()
     */
    public String getReferenceKey()
    {
        return KEY;
    }

    /**
     * Get the description of this function.
     * 
     * @see Function#getArgumentDesc()
     */
    public List getArgumentDesc()
    {
        return desc;
    }
}