package kg.apc.jmeter.functions;

 import kg.apc.jmeter.JMeterPluginsUtils;

 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;

 public class Env extends AbstractFunction {

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

     private static final String KEY = "__env";

     // Number of parameters expected - used to reject invalid calls

     private static final int MIN_PARAMETER_COUNT = 1;

     private static final int MAX_PARAMETER_COUNT = 3;

     static {

         desc.add("Name of environment variable");

         desc.add("Name of variable in which to store the result (optional)");

         desc.add("Default value");

     }

     private CompoundVariable[] values;

     /**

      * No-arg constructor.

      */

     public Env() {

     }

     /**

      * {@inheritDoc}

      */

     @Override

     public synchronized String execute(SampleResult previousResult, Sampler currentSampler)

             throws InvalidVariableException {

         String propertyName = values[0].execute();

         String propertyDefault = propertyName;

         if (values.length > 2) { // We have a 3rd parameter

             propertyDefault = values[2].execute();

         }

         String propertyValue = JMeterPluginsUtils.getEnvDefault(propertyName, propertyDefault);

         if (values.length > 1) {

             String variableName = values[1].execute();

             if (variableName.length() > 0) {// Allow for empty name

                 final JMeterVariables variables = getVariables();

                 if (variables != null) {

                     variables.put(variableName, propertyValue);

                 }

             }

         }

         return propertyValue;

     }

     /**

      * {@inheritDoc}

      */

     @Override

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

         checkParameterCount(parameters, MIN_PARAMETER_COUNT, MAX_PARAMETER_COUNT);

         values = parameters.toArray(new CompoundVariable[0]);

     }

     /**

      * {@inheritDoc}

      */

     @Override

     public String getReferenceKey() {

         return KEY;

     }

     /**

      * {@inheritDoc}

      */

     @Override

     public List<String> getArgumentDesc() {

         return desc;

     }

 }