/*
    * Copyright 2010 Fraunhofer Gesellschaft, Munich, Germany,
    * for its Fraunhofer Institute for Computer Architecture and Software
    * Technology (FIRST), Berlin, Germany. All rights reserved.
    * http://www.first.fraunhofer.de/
    */
   
   package net.kwfgrid.gwes;
   
  import net.kwfgrid.gwes.exception.GWESException;
  import org.apache.log4j.Logger;
  
  import java.util.ArrayList;
  
  /**
   * Cleans old completed or terminated workflows from memory, database and file systems.
   *
   * @author Andreas Hoheisel
   *         (<a href="http://www.andreas-hoheisel.de">www.andreas-hoheisel.de</a>)
   * @version $Id: WorkflowCleanUpManager.java 1537 2011-07-27 15:34:04Z hoheisel $
   */
  final class WorkflowCleanUpManager extends Thread {
  
      /**
       * Default Timeout in milliseconds for the workflow to be removed from the memory.
       */
      private static long DEFAULT_EXPIRYTIME_MEMORY;
  
      /**
       * Default Timeout in milliseconds for the workflow to be removed from the database.
       */
      private static long DEFAULT_EXPIRYTIME_DATABASE;
  
      static final Logger logger = Logger.getLogger(WorkflowCleanUpManager.class);
  
      private GWESEngine engine;
  
      static int threadcount = 0;
  
      private final String userID;
  
      /**
       * Constructor.
       */
      public WorkflowCleanUpManager(GWESEngine engine) {
          super("WorkflowCleanUpManager#" + (++threadcount));
          DEFAULT_EXPIRYTIME_MEMORY = Long.parseLong(System.getProperty(Constants.PROP_SYSTEM_GWES_WORKFLOW_EXPIRYTIME_MEMORY, "3600000"));
          DEFAULT_EXPIRYTIME_DATABASE = Long.parseLong(System.getProperty(Constants.PROP_SYSTEM_GWES_WORKFLOW_EXPIRYTIME_DATABASE, "604800000"));
          this.engine = engine;
          this.userID = System.getProperty(Constants.PROP_SYSTEM_GWES_SERVICE_BASE_URL_EXTERNAL)+"?"+getName();
          logger.debug("Acting with userID='"+userID+"'");
          start();
      }
  
      /**
       * Start the thread.
       */
      public final void run() {
          logger.info(this + " started ...");
          float usedMemoryPercent = 0.0f;
          ArrayList<String> expiredFromMemoryWorkflows = new ArrayList<String>();
          ArrayList<String> expiredFromDatabaseWorkflows = new ArrayList<String>();
          while (!isInterrupted()) {
              try {
                  GenericWorkflowHandlerTable table = engine.getHandlerTable();
                  long now = System.currentTimeMillis();
                  long freeMemory = Runtime.getRuntime().freeMemory();
                  long maxMemory = Runtime.getRuntime().maxMemory();
                  long totalMemory = Runtime.getRuntime().totalMemory();
                  usedMemoryPercent = 100.0f * (float) (totalMemory - freeMemory ) / (float) maxMemory;
  
                  logger.info("Memory max/total/free: " + maxMemory + "/" + totalMemory + "/" + freeMemory);
                  logger.info("Memory used: " + usedMemoryPercent + "%");
                  logger.info("Number of VM threads: "+countTotalThreads());
                  logger.info("Number of workflows in memory: " + table.size());
  
                  // search for old workflows in memory
                  for (GenericWorkflowHandler workflow : table.values()) {
                      if (workflow.getStatus() == WorkflowStatus.STATUS_COMPLETED || workflow.getStatus() == WorkflowStatus.STATUS_TERMINATED) {
                          if (now - workflow.getEndTime() > DEFAULT_EXPIRYTIME_MEMORY) {
                              expiredFromMemoryWorkflows.add(workflow.getID());
                          }
                      }
                  }
  
                  // remove old workflows from memory and table
                  for (String workflowID : expiredFromMemoryWorkflows) {
                      table.remove(workflowID);
                      logger.info("Workflow '" + workflowID + "' removed from memory.");
                  }
                  expiredFromMemoryWorkflows.clear();
  
                  // search for old workflows in memory and database
                  // example statusArray format:
                  //  "ID=hoheisel_f2968050-1d6a-11db-bacc-ad353bc1f9b1"
                  //  "status=COMPLETED"
                  //  "birthdayMs=1154003111126"
                  //  "durationUndefinedMs=527"
                  //  "durationInitiatedMs=792"
                 //  "durationRunningMs=0"
                 //  "durationActiveMs=0"
                 //  "durationSuspendedMs=0"
                 //  "durationTotalMs=1351"
                 //  "endTimeMs=1154003112477"
                 //  "level=MEMORY"
                 //  "description=test workflow"
                 String[][] statusArray = engine.getWorkflowStatusArray(3, userID);
                 for (String[] workflowStatus : statusArray) {
                     if (workflowStatus[1].equals("status=COMPLETED") || workflowStatus[1].equals("status=TERMINATED")) {
                         long endTime = Long.parseLong(workflowStatus[9].substring(workflowStatus[9].indexOf("=")+1));
                         if (now - endTime > DEFAULT_EXPIRYTIME_DATABASE) {
                             expiredFromDatabaseWorkflows.add(workflowStatus[0].substring(workflowStatus[0].indexOf("ID=")+3));
                         }
                     }
                 }
 
                 // remove old workflows from database and filesystems
                 for (String workflowID : expiredFromDatabaseWorkflows) {
                     try {
                         engine.remove(workflowID, 7, "WorkflowCleanUpManager");
                         logger.info("Workflow '" + workflowID + "' removed from database and file systems.");
                     } catch (Exception e) {
                         logger.warn("There was an exception removing workflow '"+workflowID+"', but I will continue:\n"+e);
                     }
                 }
                 expiredFromDatabaseWorkflows.clear();
             } catch (GWESException e) {
                 logger.warn("There was an GWES exception, but I will continue: \n"+e,e);
             } catch (Exception e) {
                 logger.warn("There was an exception, but I will continue: \n"+e,e);
             }
 
             // run garbage collection
             if ( usedMemoryPercent > 50.0 ) {
                 logger.info("Used memory is more than 50% of max memory. Invoking garbage collection...");
                 System.gc();
             }
 
             // wait
             try {
                 if (!isInterrupted()) {
                     logger.info("Next check in "+ DEFAULT_EXPIRYTIME_MEMORY /2+"ms");
                     Thread.sleep(DEFAULT_EXPIRYTIME_MEMORY /2);
                 }
             } catch (InterruptedException e) {
                 logger.error("I have been interrupted: " + e, e);
                 interrupt();
             }
 
         }
     }
 
     public static int countTotalThreads() {
         ThreadGroup top = Thread.currentThread().getThreadGroup();
         while ( top.getParent() != null ) {
             top = top.getParent();
         }
         return top.activeCount();
     }
 
 }