// $Header: /home/cvs/jakarta-jmeter/src/protocol/http/org/apache/jmeter/protocol/http/modifier/UserParameterModifier.java,v 1.13 2004/02/22 19:23:15 sebb Exp $
/*
 * Copyright 2001-2004 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.protocol.http.modifier;

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

import org.apache.jmeter.config.Argument;
import org.apache.jmeter.config.ConfigTestElement;
import org.apache.jmeter.engine.event.LoopIterationEvent;
import org.apache.jmeter.processor.PreProcessor;
import org.apache.jmeter.protocol.http.sampler.HTTPSampler;
import org.apache.jmeter.samplers.Sampler;
import org.apache.jmeter.testelement.TestListener;
import org.apache.jmeter.testelement.property.PropertyIterator;
import org.apache.jorphan.logging.LoggingManager;
import org.apache.log.Logger;

/**
 * This modifier will replace any http sampler's url parameter values with
 * parameter values defined in a XML file for each simulated user.
 * 

 * For example if userid and password are defined in the XML parameter file
 * for each user (ie thread), then simulated multiple user activity can occur.
 * 
 * @author     Mark Walsh
 * @version    $Revision: 1.13 $
 */
public class UserParameterModifier
    extends ConfigTestElement
    implements PreProcessor, Serializable, TestListener
{
    transient private static Logger log = LoggingManager.getLoggerForClass();
    private static final String XMLURI = "UserParameterModifier.xmluri";

    private UserSequence allAvailableUsers;

    /**
     * Default constructor.
     */
    public UserParameterModifier()
    {
    } //end constructor

    /**
     * Runs before the start of every test. Reload the Sequencer with the
     * latest parameter data for each user
     */
    public void testStarted()
    {
        // try to populate allUsers, if fail, leave as any empty set
        List allUsers = new LinkedList();
        try
        {
            UserParameterXMLParser readXMLParameters =
                new UserParameterXMLParser();
            allUsers = readXMLParameters.getXMLParameters(getXmlUri());
        }
        catch (Exception e)
        {
            // do nothing, now object allUsers contains an empty set
            log.error("Unable to read parameters from xml file " + getXmlUri());
            log.error(
                "No unique values for http requests will be substituted for " +
                "each thread",
                e);
        }
        allAvailableUsers = new UserSequence(allUsers);
    }
    public void testEnded()
    {
    }
    public void testStarted(String host)
    {
        testStarted();
    }
    public void testEnded(String host)
    {
    }

    /*
     * ------------------------------------------------------------------------
     * Methods implemented from interface org.apache.jmeter.config.Modifier
     * ------------------------------------------------------------------------
     */
     
    /**
     * Modifies an entry object to replace the value of any url parameter that
     * matches a parameter name in the XML file.
     *
     */
    public void process()
    {
        Sampler entry = getThreadContext().getCurrentSampler();
        if (!(entry instanceof HTTPSampler))
        {
            return;
        }
        HTTPSampler config = (HTTPSampler) entry;
        Map currentUser = allAvailableUsers.getNextUserMods();
        PropertyIterator iter = config.getArguments().iterator();
        while (iter.hasNext())
        {
            Argument arg = (Argument) iter.next().getObjectValue();
            // if parameter name exists in http request
            // then change its value
            // (Note: each jmeter thread (ie user) gets to have unique values)
            if (currentUser.containsKey(arg.getName()))
            {
                arg.setValue((String) currentUser.get(arg.getName()));
            }
        }
    }

    /*
     * ------------------------------------------------------------------------
     * Methods (used by UserParameterModifierGui to get/set the name of XML
     * parameter file)
     * ------------------------------------------------------------------------
     */
     
    /**
     * Return the current XML file name to be read to obtain the parameter data
     * for all users
     * 
     * @return the name of the XML file containing parameter data for each user
     */
    public String getXmlUri()
    {
        return this.getPropertyAsString(XMLURI);
    }
    
    /**
     * From the GUI screen, set file name of XML to read
     * 
     * @param xmlURI the name of the XML file containing the HTTP name value
     *               pair parameters per user
     */
    public void setXmlUri(String xmlURI)
    {
        setProperty(XMLURI, xmlURI);
    }
    
    /* (non-Javadoc)
     * @see TestListener#testIterationStart(LoopIterationEvent)
     */
    public void testIterationStart(LoopIterationEvent event)
    {
    }

    /* (non-Javadoc)
     * @see java.lang.Object#clone()
     */
    public Object clone()
    {
        UserParameterModifier clone = (UserParameterModifier) super.clone();
        clone.allAvailableUsers = allAvailableUsers;
        return clone;
    }
}