/**
    * 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.ParameterForm;
  import org.figure8.join.core.DuplicateEntityException;
  import org.figure8.join.businessobjects.environment.Parameter;
  import org.figure8.join.businessfacades.environment.ParameterManager;
  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.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import java.util.List;
  /**
   * Struts action used for managing the parameters used by software
   * project integration team for delpoyments.
   * @author <a href="mailto:jerome.evrard@gmail.com">Jerome Evrard</a>
   * @version $Revision: 1.2 $
   *
   * @struts.action path="/parameter" name="parameterForm"
   *                scope="request" parameter="op" validate="true"
   *                input="/pages/mainpage.jsp?body=/jsp/environment/parameters.jsp"
   * @struts.action-forward name="Next" path="/jsp/environment/parameters.jsp"
   * @struts.action-forward name="Values" path="/action/parameterValue?op=null"
   */
  public class ParameterActions extends JoinAction{
     
     // Static -------------------------------------------------------------------
  
     /** Get a commons logger. */
     protected static Log log = LogUtil.getLog(ParameterActions.class);
  
     /** Operation code for loading a specific Parameter */
     public static final String LOAD_OP = "load";
     /** Operation code to create a specific Parameter */
     public static final String SAVE_OP = "save";
     /** Operation code to remove a specific Parameter */
     public static final String REMOVE_OP = "remove";
  
     /** Add a parameter from the parameter values page */
     public static final String FROM_VALUES_OP = "fromValues";
     
     /** The parameter name key */
     public static final String NAME_KEY = "name";
     /** The key used for request scope attribute containing loaded parameter */
     public static final String PARAMETER_KEY = "parameter";
     /** The key used for request scope attribute containing parameters list */
     public static final String PARAMETERS_KEY = "parameters";
     /** Attribute to forward to parameters values page on parameter adding */
     public static final String FORWARD_TO_VALUES_KEY = "forwardToValues";
  
     /**
      * The request scope attribute under which is stored the Parameters that
      * has raised a DuplicateEntityException during save of another one.
      */
     public static final String DUPLICATE_PARAMETER_KEY = "duplicate";
  
  
     // Attributes ---------------------------------------------------------------
     
     /** <code>manager</code>: The parameter manager */
     private ParameterManager parameterManager;
  
  
     // Constructors -------------------------------------------------------------
  
     /** Creates a new instance of ParameterActions. */
     public ParameterActions(){
     }
  
  
     // Public -------------------------------------------------------------------
  
     /** @param manager The parameterManager to set. */
     public void setParameterManager(ParameterManager manager){
        this.parameterManager = manager;
     }
  
     
    // Override of JoinAction ---------------------------------------------------
    
    /**
     * Action to manage parameters. 
     * @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
     */
    public ActionForward doExecute(String operation, ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response)
            throws Exception{
 
       if (form instanceof ParameterForm){
          // Prepare parameter form.
          ParameterForm pForm = (ParameterForm)form;
 
          // Default is not to forward to parameters values on parameters page.
          String forward = "Next";
       	request.setAttribute(FORWARD_TO_VALUES_KEY, "false");
 
          if (LOAD_OP.equalsIgnoreCase(operation)){
             // Load a parameter for update.
             Parameter parameter = loadParameter(pForm.getName());
       	   request.setAttribute(PARAMETER_KEY, parameter);
             // Copy into form the step properties.
             PropertyUtils.copyProperties(pForm, parameter);
          }
       	else if (SAVE_OP.equalsIgnoreCase(operation)){
             // Create a new parameter.
             try {saveParameter(pForm.getName(), pForm.getDescription());}
             catch (DuplicateEntityException dee){
                // Store exception within request.
                request.setAttribute(DUPLICATE_PARAMETER_KEY, dee.getOriginalEntity());
                return mapping.findForward(forward);
             }
             // Remove form if present.
             removeObsoleteForm(mapping, request);
             // Change forward depengin on request parameter.
       	   if ("true".equalsIgnoreCase(request.getParameter("goToValues")))
                forward = "Values";
       	}
       	else if (REMOVE_OP.equalsIgnoreCase(operation)){
             // Remove a parameter
       	   removeParameter(pForm.getName());
       	}
       	else if (FROM_VALUES_OP.equalsIgnoreCase(operation)){
             // Override forward to values if specified.
       	   request.setAttribute(FORWARD_TO_VALUES_KEY, "true");
       	}
       	
      	   // Load all parameters before forwarding.
      	   request.setAttribute(PARAMETERS_KEY, loadParameters());
      	   return mapping.findForward(forward);
    	}
       // This should not happen...
       return null;
    }
 
 
    // Protected ----------------------------------------------------------------
 
    /**
     * Load all the existing parameters
     * @return The parameters list.
     */
    private List loadParameters(){
       return parameterManager.getAllParameters();
    }
 
    /**
     * Find a parameter specified by its name.
     * @param name The parameter name to load.
     * @return The parameter found or null if not exists.
     */
    protected Parameter loadParameter(String name){
       return parameterManager.getParameter(name);
    }
 
    /**
     * Create a new parameter.
     * @param name The parameter name.
     * @param description The parameter description.
     */
    protected void saveParameter(String name, String description) throws DuplicateEntityException{
       // Check if the parameter exists.
       Parameter parameter = loadParameter(name);
       if (parameter == null)
          parameter = new Parameter(name, description);
       parameter.setDescription(description);
       // Saving parameter within manager.
       log.info("Saving parameter '" + name + "'");
       parameterManager.saveParameter(parameter);
    }
 
    /**
     * Remove a parameter.
     * @param name The parameter name to remove.
     */
    private void removeParameter(String name){
       parameterManager.removeParameter(loadParameter(name));
    }
 }