package kg.apc.jmeter.functions;

 import org.apache.jmeter.engine.util.CompoundVariable;

 import org.apache.jmeter.functions.AbstractFunction;

 import org.apache.jmeter.functions.InvalidVariableException;

 import org.apache.jmeter.samplers.SampleResult;

 import org.apache.jmeter.samplers.Sampler;

 import org.apache.jmeter.threads.JMeterVariables;

 import java.util.Collection;

 import java.util.LinkedList;

 import java.util.List;

 import java.util.Random;

 public class ChooseRandom extends AbstractFunction {

     private static final List<String> desc = new LinkedList<String>();

     private static final String KEY = "__chooseRandom";

     private static final Random random = new Random(System.currentTimeMillis());

     static {

         desc.add("Any number of values to choose from");

         desc.add("Last value must be variable name where choice will be stored");

     }

     private Object[] values;

     /**

      * No-arg constructor.

      */

     public ChooseRandom() {

     }

     /**

      * {@inheritDoc}

      */

     @Override

     public synchronized String execute(SampleResult previousResult, Sampler currentSampler)

             throws InvalidVariableException {

         JMeterVariables vars = getVariables();

         String varName = ((CompoundVariable) values[values.length - 1]).execute().trim();

         int index = random.nextInt(values.length - 1);

         String choice = ((CompoundVariable) values[index]).execute();

         if (vars != null && varName != null && varName.length() > 0) {// vars will be null on TestPlan

             vars.put(varName, choice);

         }

         return choice;

     }

     /**

      * {@inheritDoc}

      */

     @Override

     public synchronized void setParameters(Collection<CompoundVariable> parameters) throws InvalidVariableException {

         checkMinParameterCount(parameters, 3);

         values = parameters.toArray();

     }

     /**

      * {@inheritDoc}

      */

     @Override

     public String getReferenceKey() {

         return KEY;

     }

     /**

      * {@inheritDoc}

      */

     @Override

     public List<String> getArgumentDesc() {

         return desc;

     }

 }