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   /* ====================================================================
    * License: 
    * 
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions
    * are met:
    *
    * 1. Redistributions of source code must retain the above copyright
    *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution,
   *    if any, must include the following acknowledgment:
   *       "This product includes software developed by 
   *        Robert Half International (http://www.rhi.com/)."
   *    Alternately, this acknowledgment may appear in the software itself,
   *    if and wherever such third-party acknowledgments normally appear.
   *
   * 4. The names "Parc", "RHI", and "Robert Half International" must
   *    not be used to endorse or promote products derived from this
   *    software without prior written permission. For written
   *    permission, please contact pete.mckinstry@rhi.com.
   *
   * 5. Products derived from this software may not be called "PARC",
   *    nor may "PARC" appear in their name, without prior written
   *    permission of Robert Half International.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   */
  package com.rhi.architecture.parc;
  
  import com.rhi.architecture.batch.AuditAgent;
  import com.rhi.architecture.batch.ConfigMixinUtils;
  import com.rhi.architecture.logging.LogUtil;
  import com.rhi.architecture.logging.Logger;
  import com.rhi.architecture.config.ConfigurationException;
  import com.rhi.architecture.resource.InitializationException;
  import com.rhi.architecture.resource.ResourceContext;
  
  import java.util.Properties;
  
  /***
   * The PipelineProcess is a process instance that runs a pipeline
   * (InputAdapter <-> Pipeline <-> OutputAdapter). It may run 
   * within a set of processes or by itself.
   * 
   *
   * @author Pete McKinstry
   * @copyright 2002, Robert Half Int'l., Inc. All rights reserved.
   *
   * @since 1.0
   */
  public class PipelineProcess implements Process {
  
     // Logger implementation. Log4J or otherwise.
     private static Logger log = null;
     static {
        try {
           log = LogUtil.getLogger();
        }
        catch (ConfigurationException e) {
           throw new ExceptionInInitializerError(
              "failure loading logger.e = " + e);
        }
     }
  
     // unique name for this Pipeline process
     private String name;
     private Properties props;
  
     // Concrete classes for the following member attributes are 
     // loaded from a property file and instantiated via reflection.
     private ExecutionStrategy strategy;
     private OutputAdapter outputAdapter;
     private InputAdapter inputAdapter;
     private AuditAgent auditAgent;
  
     /***
      * Constructor
      */
     public PipelineProcess() {
        super();
    }
 
    /***
     * Init method will be called prior to run to allow the
     * strategy to initialize itself & acquire any necessary 
     * resources. 
     * @param props
     * @throws InitializationException
     * @since 1.0
     */
    public void init(Properties props) throws InitializationException {
       this.props = props;
 
       /*
        * Override the parent program name w/ the current processes
        * name so that you load the correct configuration. 
        * Process has become a pseudo-program/application.
        */
       props.setProperty(PARCConfiguration.PROG_NAME, getName());
 
       // Load properties (w/ the new prog_name)
       ConfigMixinUtils.loadAllMixins(props);
 
       /*
        *  Re-Initialize the ResourceContext in case new resources 
        * are required.
        */
       ResourceContext ctx = new ResourceContext();
       ctx.init(props);
 
       /*
        * Create & initialize the audit agent
        * specific to this process.
        */
       String agentType = props.getProperty("AuditAgent", 
          "com.rhi.architecture.batch.NullAuditAgent");
       auditAgent = AuditAgent.getInstance(agentType);
       auditAgent.init(props);
 
       /*
        * Create & configure the pipeline components 
        */
       configurePipeline(props);
 
    }
 
    /***
     * Loads the appropriate pipeline components based on the config
     * settings. It calls getPipeline() to deal w/ the Filter details, 
     * but maintains control over the input & output adapters as 
     * well as the execution strategy.
     * 
     * @param props
     * @throws InitializationException
     * 
     * @since 1.0
     */
    private void configurePipeline(Properties props)
       throws InitializationException {
       try {
          log.info("process name = " + getName());
 
          // 1. set strategy.
          // 	a default strategy is provided, but you should always 
          // set your own just to be double sure.
          String strategyClassName =
             props.getProperty(
                "ExecutionStrategy",
                "com.rhi.architecture.parc.SingleCallStrategy");
          Class strategyClass = Class.forName(strategyClassName);
          strategy = (ExecutionStrategy) strategyClass.newInstance();
          strategy.init(props);
          
          // 2. create the correct input adapter
          String iAdapterClassName = props.getProperty("InputAdapter");
          log.info("input adapter = " + iAdapterClassName);
 
          Class iAdapterClass = Class.forName(iAdapterClassName);
          inputAdapter = (InputAdapter) iAdapterClass.newInstance();
          inputAdapter.init(props);
 
          // 3. create the correct output adapter
          String oAdapterClassName = props.getProperty("OutputAdapter");
          Class oAdapterClass = Class.forName(oAdapterClassName);
          outputAdapter = (OutputAdapter) oAdapterClass.newInstance();
          outputAdapter.init(props);
 
          inputAdapter.setAuditAgent(getAuditAgent());
          outputAdapter.setAuditAgent(getAuditAgent());
 
          // 5. Initialize the strategy object w/ all the proper 
          // 	components.
          strategy.setInputAdapter(getInputAdapter());
          strategy.setOutputAdapter(getOutputAdapter());
          strategy.setPipeline(getPipeline());
       }
       catch (ClassNotFoundException cnfe) {
          throw new InitializationException("ClassNotFoundException", cnfe);
       }
       catch (InstantiationException ie) {
          throw new InitializationException("InstantiationException", ie);
       }
       catch (IllegalAccessException iae) {
          throw new InitializationException("IllegalAccessException", iae);
       }
    }
 
    /***
     * This method should construct a Pipeline, a set of 
     * Filters, attach those Filters to the Pipeline, and
     * return the fully configured Pipeline to the framework
     * for execution. 
     * <p />
     * A default implementation has been provided here for the
     * simplest case. It is driven from property file settings
     * and assumes default constructors exist for both the 
     * Pipeline and all the Filters. It is anticipated that this
     * will be to restrictive for many non-trivial applications. 
     * In those cases, this method should be overridden and 
     * implemented appropriately. 
     *
     * @return Pipeline
     * @throws InitializationException
     * @since 1.0
     */
    public Pipeline getPipeline() throws InitializationException {
 
       try {
          Properties props = getProperties();
          // get the channel class, use ArrayList as the default.
          String defaultChannel =
             props.getProperty(
                "Channel",
                "com.rhi.architecture.parc.ArrayListQueue");
          Class channelClass = Class.forName(defaultChannel);
          Channel channel = (Channel) channelClass.newInstance();
 
          // get the pipeline class - no default.
          String pipelineClassName = props.getProperty("Pipeline", 
             "com.rhi.architecture.parc.SerialMTPipeline");
          Class pipelineClass = Class.forName(pipelineClassName);
          Pipeline pipeline = (Pipeline) pipelineClass.newInstance();
          pipeline.init(channel);
 
          // Filters will be added to the pipeline in numeric order,
          // until a number is missing. The numbering starts w/ 0.
          int count = 0;
          while (true) {
             String nextName = "Filter" + count;
             String filterClassName =
                props.getProperty(nextName, "not found");
             if (filterClassName.equals("not found")) {
                break;
             }
             log.info("loading " + nextName + " = " + filterClassName);
             Class filterClass = Class.forName(filterClassName);
             Filter filter = (Filter) filterClass.newInstance();
             filter.init(props);
             pipeline.addFilter(filter);
             count++;
          }
 
          return pipeline;
       }
       catch (ClassNotFoundException cnfe) {
          throw new InitializationException("ClassNotFoundException", cnfe);
       }
       catch (InstantiationException ie) {
          throw new InitializationException("InstantiationException", ie);
       }
       catch (IllegalAccessException iae) {
          throw new InitializationException("IllegalAccessException", iae);
       }
    }
 
    /***
     * Run the Process. For PipelineProcess, this will 
     * call strategy.run() & then outputAdapter.close()
     *
     * @exception ProcessingException
     * 
     * @since 1.0
     */
    public void run() throws ProcessingException {
       log.debug("run()");
       try {
          strategy.run();
 
          // after all the batches are processed, do any work
          // that must happen once & only once per interface run.
          outputAdapter.close();
       }
       catch (ProcessingException pe) {
          log.error("ProcessingException thrown.", pe);
          throw new ProcessingException(pe.toString(), pe);
       }
    }
 
    /***
     * Perform any cleanup required. This allows the Process to 
     * keep resources open after the run() method in case a 
     * multi-call strategy is used to execute run() repeatedly.
     * 
     * @since 1.0
     */
    public void cleanup() {
       // run cleanup on input adapter & set reference to null.
       if (inputAdapter != null) {
          inputAdapter.cleanup();
          inputAdapter = null;
       }
       // run cleanup on output adapter & set reference to null.
       if (outputAdapter != null) {
          outputAdapter.cleanup();
          outputAdapter = null;
       }
       // audit agent
       if (auditAgent != null) {
          auditAgent = null;
       }
       // exec strategy
       if (strategy != null) {
          strategy.cleanup();
          strategy = null;
       }
       //clear the properties hashtable.
       props.clear();
 
       /*
        * Implementation Note: The ResourceContext should not be 
        * cleared here so that it can be shared by Process objects. 
        * It is finally cleaned up by the BatchApplication when 
        * all processes are complete.
        */
    }
 
    /***
     * getName returns the configured name for this process. This
     * method must return a unique identifier for each process 
     * running w/in the same BatchApplication. It is used to 
     * identify properties that are specific to a given Process.
     *
     * @return String
     *
     * @since 1.0
     */
    public String getName() {
       if (name == null) {
          String tmp = ProcessSet.class.getName();
          int idx = tmp.lastIndexOf(".");
          return tmp.substring(idx + 1);
       }
       return name;
    }
    /***
     * setName is called by either the ProcessSet if this Process is 
     * contained w/in a ProcessSet to provide it w/ a unique name for 
     * property lookups. (name precedes properties specific to the 
     * process)
     *
     * @param name
     *
     * @since 1.0
     */
    public void setName(String name) {
       this.name = name;
    }
 
    /***
     * The interface application defers execution to a strategy
     * interface.
     *
     * @return ExecutionStrategy
     *
     * @since 1.0
     */
    public ExecutionStrategy getExecutionStrategy() {
       return strategy;
    }
    /***
     * Set the strategy
     *
     * @param strategy
     *
     * @since 1.0
     */
    public void setExecutionStrategy(ExecutionStrategy strategy) {
       this.strategy = strategy;
    }
 
    /***
     * Return the Output Adapter that persists the work set
     * after processing is completed. 
     *
     * @return OutputAdapter
     *
     * @since 1.0
     */
    public OutputAdapter getOutputAdapter() {
       return outputAdapter;
    }
    /***
     * Set the output adapter
     *
     * @param outputAdapter
     *
     * @since 1.0
     */
    public void setOutputAdapter(OutputAdapter outputAdapter) {
       this.outputAdapter = outputAdapter;
    }
 
    /***
     * Return the Input Adapter that selects the work set to 
     * process. Typically this adapter will query the database
     * or file system for a group of records to transform.
     *
     * @return InputAdapter
     *
     * @since 1.0
     */
    public InputAdapter getInputAdapter() {
       return inputAdapter;
    }
    /***
     * Set the input adapter
     *
     * @param inputAdapter
     *
     * @since 1.0
     */
    public void setInputAdapter(InputAdapter inputAdapter) {
       this.inputAdapter = inputAdapter;
    }
 
    /***
     * Returns the auditAgent.
     * @return AuditAgent
     */
    public AuditAgent getAuditAgent() {
       return auditAgent;
    }
    /***
     * Sets the auditAgent.
     * @param auditAgent The auditAgent to set
     */
    public void setAuditAgent(AuditAgent auditAgent) {
       this.auditAgent = auditAgent;
    }
 
    /*** 
     * get the configuration properties
     *
     * @return Properties
     *
     * @since 1.0
     */
    public Properties getProperties() {
       return props;
    }
 
    /***
     * Returns the logger instance
     * @return Logger
     */
    public static Logger log() {
       return log;
    }
 
 }