/*
 * Copyright (c) 2010 The Regents of the University of California.
 * All rights reserved.
 *
 * '$Author: welker $'
 * '$Date: 2010-05-05 22:21:26 -0700 (Wed, 05 May 2010) $' 
 * '$Revision: 24234 $'
 * 
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and its documentation for any purpose, provided that the above
 * copyright notice and the following two paragraphs appear in all copies
 * of this software.
 *
 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
 * FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
 * THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
 * PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
 * CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
 * ENHANCEMENTS, OR MODIFICATIONS.
 *
 */
package org.kepler.workflowscheduler.gui;

import java.io.StringReader;
import java.util.Vector;
import java.util.concurrent.locks.Lock;

import javax.swing.JOptionPane;
import javax.swing.SwingWorker;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.kepler.module.workflowschedulergui.Initialize;
import org.xml.sax.ContentHandler;
import org.xml.sax.ErrorHandler;
import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.XMLReaderFactory;

import edu.ucsb.nceas.schedulerclient.WorkflowSchedulerClient;
import edu.ucsb.nceas.workflowscheduler.scheduler.WorkflowSchedulerException;

/**
 * This class represents a worker to search existing schedules from remote
 * server in a  in a dedicated thread.
 * @author tao
 *
 */
public class SearchScheduleSwingWorker extends SwingWorker
{
  private static final Log log = LogFactory.getLog(SearchScheduleSwingWorker.class.getName());
  public static final String PARSERNAME = "org.apache.xerces.parsers.SAXParser";
  
  private String workflowLSID = null;
  private String karLSID = null;
  //private String workflowName = null;
  //private String karLSID = null;
  private Schedule[] schedules = null;
  private ScheduleChangeController scheduleChangeController= null;
  private Lock existingScheduleTablelock = null;
 
  /**
   * Constructor
   * @param workflowLSID the workflow id will be search
   */
  public SearchScheduleSwingWorker(ScheduleChangeController controller, 
                                  String workflowLSID, String karLSID, Lock existingScheduleTablelock) throws Exception
  {
    super();
    if(workflowLSID == null || workflowLSID.trim().equals(""))
    {
      throw new Exception("The workflow id for seaching existing schedules couldn't be blank ");
    }
    if(karLSID == null || karLSID.trim().equals(""))
    {
      throw new Exception("The kar id for seaching existing schedules couldn't be blank ");
    }
    this.scheduleChangeController = controller;
    this.karLSID = karLSID;
    this.existingScheduleTablelock = existingScheduleTablelock;
    this.workflowLSID = workflowLSID;
    //this.workflowName = workflowName;
    //this.karLSID = karLSID;
  }
  
 

  /**
   * Compute the value to be returned by the <code>get</code> method.
   */
  public Object doInBackground()
  {
    if(existingScheduleTablelock != null)
    {
      existingScheduleTablelock.lock();
    }   
    searchSchedules();
    if(existingScheduleTablelock != null)
    {
      existingScheduleTablelock.unlock();
    }
    return null;
  }
  
  /*
   * Search existing schedules from scheduler server and update the
   * existing table
   */
  private void searchSchedules()
  {
    String schedulerURL = Initialize.getSchedulerURL();
    String sessionID = "unknown"; 
    String authenticationServiceURL = null;
    try
    {
      if(schedulerURL == null || schedulerURL.trim().equals(""))
      {
        throw new WorkflowSchedulerException("Kepler couldn't find the workflow scheduler url in the configuration file.");
      }
      WorkflowSchedulerClient client = new WorkflowSchedulerClient(schedulerURL, sessionID, authenticationServiceURL);
      String result = client.getJobs(workflowLSID, karLSID);
      //System.out.println("search result is:\n"+result);
      parse(result);
      if(scheduleChangeController != null)
      {
        scheduleChangeController.update(schedules);
        scheduleChangeController.complete();
      }
    
    }
    catch(WorkflowSchedulerException e)
    {
      JOptionPane.showMessageDialog(null, "Search existing schedule failed:\n"+
                              e.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
      if(scheduleChangeController != null)
      {
        scheduleChangeController.stopProgressBar();
      }
      
    }
    catch(Exception e)
    {
      log.error(e.getMessage());
      if(scheduleChangeController != null)
      {
        scheduleChangeController.stopProgressBar();
      }
    }
     
    
  }
  
  /*
   * Parse the result xml by sax parser
   */
  private void parse(String result)
  {
    if(result != null && !result.trim().equals(""))
    {
      StringReader xmlReader = new StringReader(result);
      try
      {
        XMLReader parser = null;
        parser = XMLReaderFactory.createXMLReader(PARSERNAME);
        QueryingSchedulerServerResultParser handler = new 
                      QueryingSchedulerServerResultParser();
        parser.setContentHandler((ContentHandler) handler);
        parser.setErrorHandler((ErrorHandler) handler);
        parser.parse(new InputSource(xmlReader));
        Vector<Schedule> schedulesVector = handler.getSchedules();
        if(schedulesVector != null && schedulesVector.size() >0)
        {
          //System.out.println("The schedules vector size is "+ schedulesVector.size());
          schedules = new Schedule[schedulesVector.size()];
          schedulesVector.toArray(schedules);
          //System.out.println("The schedules array size is "+schedules.length); 
        }
        else
        {
          //System.out.println("The result schedules vector is null");                 
        }
        
      }
      catch(Exception e)
      {
        log.error("Couldn't parse the return document -"+e.getMessage());
      }
    }
  }

}