/*
 * 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.jmeter.functions;

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

import org.apache.commons.jexl3.JexlArithmetic;
import org.apache.commons.jexl3.JexlBuilder;
import org.apache.commons.jexl3.JexlContext;
import org.apache.commons.jexl3.JexlEngine;
import org.apache.commons.jexl3.JexlExpression;
import org.apache.commons.jexl3.MapContext;
import org.apache.jmeter.engine.util.CompoundVariable;
import org.apache.jmeter.samplers.SampleResult;
import org.apache.jmeter.samplers.Sampler;
import org.apache.jmeter.testelement.ThreadListener;
import org.apache.jmeter.threads.JMeterContext;
import org.apache.jmeter.threads.JMeterContextService;
import org.apache.jmeter.threads.JMeterVariables;
import org.apache.jmeter.util.JMeterUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * A function which understands Commons JEXL3
 * @since 3.0
 */
// For unit tests, see TestJexlFunction
public class Jexl3Function extends AbstractFunction implements ThreadListener {

    private static final Logger log = LoggerFactory.getLogger(Jexl3Function.class);

    private static final String KEY = "__jexl3"; //$NON-NLS-1$

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

    private static final ThreadLocal<JexlEngine> threadLocalJexl = new ThreadLocal<>();

    static
    {
        desc.add(JMeterUtils.getResString("jexl_expression")); //$NON-NLS-1$
        desc.add(JMeterUtils.getResString("function_name_paropt"));// $NON-NLS1$
    }

    private Object[] values;

    /** {@inheritDoc} */
    @Override
    public String execute(SampleResult previousResult, Sampler currentSampler)
            throws InvalidVariableException
    {
        String str = ""; //$NON-NLS-1$

        CompoundVariable var = (CompoundVariable) values[0];
        String exp = var.execute();

        String varName = ""; //$NON-NLS-1$
        if (values.length > 1) {
            varName = ((CompoundVariable) values[1]).execute().trim();
        }

        JMeterContext jmctx = JMeterContextService.getContext();
        JMeterVariables vars = jmctx.getVariables();

        try
        {
            JexlContext jc = new MapContext();
            jc.set("log", log); //$NON-NLS-1$
            jc.set("ctx", jmctx); //$NON-NLS-1$
            jc.set("vars", vars); //$NON-NLS-1$
            jc.set("props", JMeterUtils.getJMeterProperties()); //$NON-NLS-1$
            // Previously mis-spelt as theadName
            jc.set("threadName", Thread.currentThread().getName()); //$NON-NLS-1$
            jc.set("sampler", currentSampler); //$NON-NLS-1$ (may be null)
            jc.set("sampleResult", previousResult); //$NON-NLS-1$ (may be null)
            jc.set("OUT", System.out);//$NON-NLS-1$

            // Now evaluate the script, getting the result
            JexlExpression e = getJexlEngine().createExpression( exp );
            Object o = e.evaluate(jc);
            if (o != null)
            {
                str = o.toString();
            }
            if (vars != null && varName.length() > 0) {// vars will be null on TestPlan
                vars.put(varName, str);
            }
        } catch (Exception e)
        {
            log.error("An error occurred while evaluating the expression \""
                    + exp + "\"\n",e);
        }
        return str;
    }
    
    /**
     * FIXME Remove when upgrading to commons-jexl3-3.1
     *
     */
    private static class JMeterArithmetic extends JexlArithmetic {
        public JMeterArithmetic(boolean astrict) {
            super(astrict);
        }

        /**
         * A workaround to create an operator overload.
         *  the 'size' method is discovered through introspection as
         * an overload of the 'size' operator; this creates an entry in a cache for
         * that arithmetic class avoiding to re-discover the operator overloads
         * (Uberspect) on each execution. So, no, this method is not called; it is just
         * meant as a workaround of the bug.
         * @see <a href="https://issues.apache.org/jira/browse/JEXL-186">JEXL-186</a>
         * @param jma an improbable parameter class
         * @return 1
         */
        @SuppressWarnings("unused")
        public int size(JMeterArithmetic jma) {
            return 1;
        }
    }
    /**
     * Get JexlEngine from ThreadLocal
     * @return JexlEngine
     */
    private static JexlEngine getJexlEngine() {
        JexlEngine engine = threadLocalJexl.get();
        if(engine == null) {
            engine = new JexlBuilder()
                    .cache(512)
                    .silent(true)
                    .strict(true)
                    // debug is true by default an impact negatively performances
                    // by a factory of 10
                    // Use JexlInfo if necessary
                    .debug(false)
                    // see https://issues.apache.org/jira/browse/JEXL-186
                    .arithmetic(new JMeterArithmetic(true))
                    .create();
            threadLocalJexl.set(engine);
        }
        return engine;
    }
    
    /** {@inheritDoc} */
    @Override
    public List<String> getArgumentDesc()
    {
        return desc;
    }

    /** {@inheritDoc} */
    @Override
    public String getReferenceKey()
    {
        return KEY;
    }

    /** {@inheritDoc} */
    @Override
    public void setParameters(Collection<CompoundVariable> parameters)
            throws InvalidVariableException
    {
        checkParameterCount(parameters, 1, 2);
        values = parameters.toArray();
    }

    @Override
    public void threadStarted() {
    }

    @Override
    public void threadFinished() {
        JexlEngine engine = threadLocalJexl.get();
        if(engine != null) {
            engine.clearCache();
            threadLocalJexl.remove();
        }
    }

}

@@ -920,56 +920,8 @@
 t;%0A%0A
-import org.apache.commons.jexl3.JexlArithmetic;%0A
 impo
@@ -4123,971 +4123,8 @@
 /**%0A
-     * FIXME Remove when upgrading to commons-jexl3-3.1%0A     *%0A     */%0A    private static class JMeterArithmetic extends JexlArithmetic %7B%0A        public JMeterArithmetic(boolean astrict) %7B%0A            super(astrict);%0A        %7D%0A%0A        /**%0A         * A workaround to create an operator overload.%0A         *  the 'size' method is discovered through introspection as%0A         * an overload of the 'size' operator; this creates an entry in a cache for%0A         * that arithmetic class avoiding to re-discover the operator overloads%0A         * (Uberspect) on each execution. So, no, this method is not called; it is just%0A         * meant as a workaround of the bug.%0A         * @see %3Ca href=%22https://issues.apache.org/jira/browse/JEXL-186%22%3EJEXL-186%3C/a%3E%0A         * @param jma an improbable parameter class%0A         * @return 1%0A         */%0A        @SuppressWarnings(%22unused%22)%0A        public int size(JMeterArithmetic jma) %7B%0A            return 1;%0A        %7D%0A    %7D%0A    /**%0A
     
@@ -4670,142 +4670,8 @@
 se)%0A
-                    // see https://issues.apache.org/jira/browse/JEXL-186%0A                    .arithmetic(new JMeterArithmetic(true))%0A
     

Update commons-jexl3 to 3.1 from 3.0 Remove workaround as issue JEXL-186 is fixed in 3.1