/**
    * Copyright 2005-2006 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.ResourceVersionForm;
  import org.figure8.join.core.DuplicateEntityException;
  import org.figure8.join.businessobjects.environment.ResourceVersion;
  import org.figure8.join.businessobjects.environment.VersionedResourceType;
  import org.figure8.join.businessfacades.environment.ResourceManager;
  import org.figure8.join.util.LogUtil;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.beanutils.PropertyUtils;
  import org.apache.struts.action.ActionForm;
  import org.apache.struts.action.ActionForward;
  import org.apache.struts.action.ActionMapping;
  
  import javax.servlet.http.HttpSession;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import java.util.List;
  import java.lang.reflect.Constructor;
  /**
   * This is a Struts action for managing resource versions.
   * @author <a href="mailto:laurent.broudoux@free.fr">Laurent Broudoux</a>
   * @version $Revision: 1.1 $
   *
   * @struts.action path="/resourceVersion" name="resourceVersionForm"
   *                scope="request" parameter="op" validate="true"
   *                input="/pages/mainpage.jsp?body=/jsp/environment/resourceversions.jsp"
   * @struts.action-forward name="ResourceVersions" path="/jsp/environment/resourceversions.jsp"
   */
  public class ResourceVersionActions extends JoinAction{
  
     // Static -------------------------------------------------------------------
  
     /** Get a commons logger. */
     private static final Log log = LogUtil.getLog(ResourceVersionActions.class);
  
     /** Operation code for loading a specified ResourceVersion */
     public static final String LOAD_OP = "load";
     /** Operation code for saving (create or update) a specified ResourceVersion */
     public static final String SAVE_OP = "save";
     /** Operation code for searching resource versions using their type */
     public static final String SEARCH_OP = "search";
  
     /**
      * The session scope attribute under which the ResourceVersion object
      * currently selected by our logged-in User is stored.
      */
     public static final String RESOURCE_VERSION_KEY = "resourceVersion";
     /**
      * The request scope attribute under which the retrieved ResourceVersions
      * list is stored.
      */
     public static final String RESOURCE_VERSIONS_KEY = "resourceVersions";
     /**
      * The request scope attribute under which is stored the ResourceVersion that
      * has raised a DuplicateEntityException during save of another one.
      */
     public static final String DUPLICATE_RESOURCE_VERSION_KEY = "duplicate";
  
  
     // Attributes ---------------------------------------------------------------
  
     /** The ResourceManager to use */
     private ResourceManager resourceManager = null;
  
  
     // Constructors -------------------------------------------------------------
  
     /** Creates a new instance of ResourceVersionActions. */
     public ResourceVersionActions(){
     }
  
  
     // Public -------------------------------------------------------------------
  
     /** @param manager The ResourceManager to use */
     public void setResourceManager(ResourceManager manager){
        this.resourceManager = manager;
     }
  
  
     // Implementation of JoinAction ---------------------------------------------
 
    /**
     *
     * @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");
 
       // Common : we always need types list.
       List resourceTypes = resourceManager.getResourceTypes(request.getParameter("category"));
       request.setAttribute(ResourceTypeActions.RESOURCE_TYPES_KEY, resourceTypes);
 
       if (LOAD_OP.equals(operation)){
          return loadResourceVersion(mapping, form, request, response);
       }
       else if (SAVE_OP.equals(operation)){
          return saveResourceVersion(mapping, form, request, response);
       }
       else if (SEARCH_OP.equals(operation)){
          return searchResourceVersions(mapping, form, request, response);
       }
       else{
          // Default : empty resources management page.
          request.getSession().removeAttribute(RESOURCE_VERSION_KEY);
          return mapping.findForward("ResourceVersions");
       }
    }
 
 
    // Protected ----------------------------------------------------------------
 
    /**
     * Load a specified resource versin from datastore and fill form with it.
     * @return A forward to the next view to render and display
     */
    protected ActionForward loadResourceVersion(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response)
          throws Exception{
 
       if (form instanceof ResourceVersionForm){
          // Get the requested resource version from manager.
          ResourceVersionForm rForm = (ResourceVersionForm)form;
          ResourceVersion version = resourceManager.getResourceVersion(rForm.getId());
 
          // Store resource version within session.
          HttpSession session = request.getSession();
          session.setAttribute(RESOURCE_VERSION_KEY, version);
          // Copy resource type into form properties.
          PropertyUtils.copyProperties(rForm, version);
 
          return mapping.findForward("ResourceVersions");
       }
       // This should not happen...
       return null;
    }
 
    /**
     * Save a resource version into datastore. The resource version may be an already existing
     * one or a new one (this is indeed a create or update method).
     * @return A forward to the next view to render and display
     */
    protected ActionForward saveResourceVersion(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response)
          throws Exception{
 
       if (form instanceof ResourceVersionForm){
          ResourceVersionForm rForm = (ResourceVersionForm)form;
 
          // Is there a resource version to update in session ?
          HttpSession session = request.getSession();
          ResourceVersion version = (ResourceVersion)session.getAttribute(RESOURCE_VERSION_KEY);
 
          // Create a new resource version or populate existing with form.
          if (version == null){
             log.info("Creation of a new ResourceVersion with name: " + rForm.getName());
             VersionedResourceType resourceType = (VersionedResourceType)resourceManager.getResourceType(
                     rForm.getResourceTypeKey());
             version = new ResourceVersion(rForm.getName(), rForm.getDescription(), resourceType);
          }
          else{
             log.info("Update of existing ResourceVersion having name: " + rForm.getName());
             PropertyUtils.copyProperties(version, rForm);
          }
          // Save resource version using manager.
          try {resourceManager.saveResourceVersion(version);}
          catch (DuplicateEntityException dee){
             // Store exception within request.
             request.setAttribute(DUPLICATE_RESOURCE_VERSION_KEY, dee);
             return searchResourceVersions(mapping, form, request, response);
          }
 
          // Remove form and session attribute if present.
          session.removeAttribute(RESOURCE_VERSION_KEY);
          removeObsoleteForm(mapping, request);
 
          // Add resource versions list before forwarding.
          return searchResourceVersions(mapping, form, request, response);
       }
       // This should not happen...
       return null;
    }
 
    /**
     * Retrieve a list of ResourceVersions using the resource type criteria.
     * @return A forward to the next view to render and display
     */
    protected ActionForward searchResourceVersions(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response)
       throws Exception{
 
       if (form instanceof ResourceVersionForm){
          ResourceVersionForm rForm = (ResourceVersionForm)form;
 
          // Retrieve all the resources we need.
          VersionedResourceType resourceType = (VersionedResourceType)resourceManager.getResourceType(rForm.getResourceTypeKey());
          List resourceVersions = resourceManager.getResourceVersions(resourceType);
 
          // Store them into request attributes before forwarding.
          request.setAttribute(RESOURCE_VERSIONS_KEY, resourceVersions);
          request.setAttribute("resourceTypeKey", rForm.getResourceTypeKey());
          return mapping.findForward("ResourceVersions");
       }
       // This should not happen...
       return null;
    }
 }