/**
    * Copyright 2005-2007 the original author or authors.
    *
    * Licensed under the Gnu General Pubic 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.opensource.org/licenses/gpl-license.php
    *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   * See the Gnu General Public License for more details.
   */
  package org.figure8.join.control.action;
  
  import org.figure8.join.control.JoinAction;
  import org.figure8.join.control.form.EISMappingForm;
  import org.figure8.join.businessobjects.environment.EIS;
  import org.figure8.join.businessobjects.environment.Gateway;
  import org.figure8.join.businessobjects.environment.EISMapping;
  import org.figure8.join.businessfacades.environment.ResourceManager;
  import org.figure8.join.util.LogUtil;
  
  import org.apache.commons.logging.Log;
  import org.apache.struts.action.ActionForm;
  import org.apache.struts.action.ActionForward;
  import org.apache.struts.action.ActionMapping;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  /**
   * This is a Struts action for managing all operations related to mappings between EIS and Gateways.
   * @author <a href="mailto:laurent.broudoux@free.fr">Laurent Broudoux</a>
   * @version $Revision: 1.1 $
   *
   * @struts.action path="/eisMapping" name="eisMappingForm"
   *                scope="request" parameter="op" validate="true"
   *                input="/pages/mainpage.jsp?body=/jsp/environment/eismappings.jsp"
   * @struts.action-forward name="Gateway" path="/action/gateway?category=Gateway&amp;op=details"
   * @struts.action-forward name="EISMappings" path="/jsp/environment/eismappings.jsp"
   */
  public class EISMappingActions extends JoinAction{
  
     // Static -------------------------------------------------------------------
  
     /** Get a commons logger. */
     private static final Log log = LogUtil.getLog(EISMappingActions.class);
  
     /** Operation code for loading a specific EISMapping */
     public static final String LOAD_OP = "load";
     /** Operation code for saving a EISMapping (create) */
     public static final String CREATE_OP = "create";
     /** Operation code for closing a EISMapping (close) */
     public static final String CLOSE_OP = "close";
     /** Operation code for retrieving EISMappings for a gateway */
     public static final String VIEW_OP = "view";
  
     /**
      * The session scope attribute under which the EISMapping object
      * currently selected by our logged-in User is stored.
      */
     public static final String MAPPING_KEY = "mapping";
     /**
      * The request scope attribute under which the retrieved EISMappings
      * list is stored.
      */
     public static final String MAPPINGS_KEY = "mappings";
  
  
     // Attributes ---------------------------------------------------------------
  
     /** The ResourceManager to use */
     private ResourceManager resourceManager = null;
  
  
     // Constructors -------------------------------------------------------------
  
     /** Creates a new instance of EISMappingActions. */
     public EISMappingActions(){
     }
  
  
     // Public -------------------------------------------------------------------
  
     /** @param manager The ResourceManager implementation to use */
     public void setResourceManager(ResourceManager manager){
        this.resourceManager = manager;
     }
  
  
     // Implementation of JoinAction ---------------------------------------------
  
     /**
      * Abstract method that subclasses must implement. The real execution must
      * be done here according to the specified <b>operation</b>. ActionForward
      * returned by execution should only point on page fragment : this superclass
      * is responsible of including them within a whole page.
      * @param operation String representing the operation to invoke on Action
     * @param mapping Mapping between forwards name and path for this action
     * @param form The form object containing request parameters
     * @param request The servlet container request wrapper
     * @param response The servlet container response wrapper
     * @return A forward to the next view to render and display
     * @throws Exception such as InfraStructureExceptions ...
     */
    public ActionForward doExecute(String operation, ActionMapping mapping, ActionForm form,
                                   HttpServletRequest request, HttpServletResponse response) throws Exception{
       // Trace operation to execute.
       log.debug("doExecute() called for '" + operation + "' operation");
 
       if (LOAD_OP.equals(operation)){
          return loadMapping(mapping, form, request, response);
       }
       else if (CREATE_OP.equals(operation)){
          return createMapping(mapping, form, request, response);
       }
       else if (CLOSE_OP.equals(operation)){
          return closeMapping(mapping, form, request, response);
       }
       // This should not happen...
       return null;
    }
 
 
    // Protected ----------------------------------------------------------------
 
    /**
     * Load a specified EIS mapping from datastore and fill form with it.
     * @return A forward to the next view to render and display
     */
    protected ActionForward loadMapping(ActionMapping mapping, ActionForm form,
                                        HttpServletRequest request, HttpServletResponse response) throws Exception{
       // This should not happen...
       return null;
    }
 
    /**
     * Create an EIS mapping into datastore and bind specified EIS and gateway to it.
     * @return A forward to the next view to render and display
     */
    protected ActionForward createMapping(ActionMapping mapping, ActionForm form,
                                          HttpServletRequest request, HttpServletResponse response) throws Exception{
       if (form instanceof EISMappingForm){
          // Get the requested EIS and Gateway from manager.
          EISMappingForm eForm = (EISMappingForm)form;
          EIS eis = (EIS)resourceManager.getResource(eForm.getEISId());
          Gateway gateway = (Gateway)resourceManager.getResource(eForm.getGatewayName());
 
          // Map EIS and gateway by creating a mapping.
          log.info("Creating a mapping for " + eis.getName() + " EIS onto "
                  + gateway.getName() + " gateway");
          resourceManager.mapEISOnGateway(eis, gateway);
 
          // Store gateway into request, asking to refresh its view, before forwarding...
          request.setAttribute(GatewayActions.GATEWAY_KEY, gateway);
          log.info("Forwarding to " + mapping.findForward("Gateway").getPath());
          return mapping.findForward("Gateway");
       }
       // This should not happen...
       return null;
    }
 
    /**
     * Close an EIS mapping and update the gateway.
     * @return A forward to the next view to render and display
     */
    protected ActionForward closeMapping(ActionMapping mapping, ActionForm form,
                                         HttpServletRequest request, HttpServletResponse response) throws Exception{
       if (form instanceof EISMappingForm){
          // Get the request EISMapping from manager.
          EISMappingForm eForm = (EISMappingForm)form;
          EISMapping eisMapping = resourceManager.getEISMapping(eForm.getId());
 
          // Close eis mapping using manager.
          log.info("Closing the EIS mapping having identifier '" + eisMapping.getId() + "'");
          resourceManager.closeEISMapping(eisMapping);
 
          // Store gateway into request, asking to refresh its view, before forwarding...
          request.setAttribute(GatewayActions.GATEWAY_KEY, eisMapping.getGateway());
          return mapping.findForward("Gateway");
       }
       // This should not happen...
       return null;
    }
 }