/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache 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.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.myfaces.application;
  
  import javax.el.MethodExpression;
  import javax.faces.application.Application;
  import javax.faces.application.ConfigurableNavigationHandler;
  import javax.faces.application.NavigationCase;
  import javax.faces.application.NavigationHandler;
  import javax.faces.component.ActionSource;
  import javax.faces.component.ActionSource2;
  import javax.faces.component.UIComponent;
  import javax.faces.component.UIViewRoot;
  import javax.faces.context.FacesContext;
  import javax.faces.el.MethodBinding;
  import javax.faces.event.AbortProcessingException;
  import javax.faces.event.ActionEvent;
  import javax.faces.event.ActionListener;
  import javax.faces.event.PhaseId;
  import org.apache.myfaces.view.facelets.ViewPoolProcessor;
  import org.apache.myfaces.view.facelets.pool.ViewPool;
  
  
  /**
   * @author Manfred Geiler (latest modification by $Author$)
   * @author Anton Koinov
   * @version $Revision$ $Date$
   */
  public class ActionListenerImpl implements ActionListener
  {
      public void processAction(ActionEvent actionEvent) throws AbortProcessingException
      {
          FacesContext facesContext = FacesContext.getCurrentInstance();
          Application application = facesContext.getApplication();
          UIComponent component = actionEvent.getComponent();
          
          MethodExpression methodExpression = null;
          MethodBinding methodBinding = null;
          
          String fromAction = null;
          String outcome = null;
          
          if (component instanceof ActionSource2)
          {
              // Must be an instance of ActionSource2, so don't look on action if the actionExpression is set 
              methodExpression = ((ActionSource2) component).getActionExpression();            
          }
          if (methodExpression == null && component instanceof ActionSource)
          {
              // Backwards compatibility for pre-1.2.
              methodBinding = ((ActionSource) component).getAction();
          }
          
          if (methodExpression != null)
          {
              fromAction = methodExpression.getExpressionString();
  
              Object objOutcome = methodExpression.invoke(facesContext.getELContext(), null);
              if (objOutcome != null)
              {
                  outcome = objOutcome.toString();
              }
              
          }
          
          else if (methodBinding != null)
          {
              fromAction = methodBinding.getExpressionString();
              Object objOutcome = methodBinding.invoke(facesContext, null);
  
              if (objOutcome != null)
              {
                  outcome = objOutcome.toString();
              }
  
          }
          
          UIViewRoot root = facesContext.getViewRoot();
          ViewPoolProcessor processor = ViewPoolProcessor.getInstance(facesContext);
          ViewPool pool = (processor != null) ? processor.getViewPool(facesContext, root) : null;
          if (pool != null && pool.isDeferredNavigationEnabled() && 
              processor.isViewPoolStrategyAllowedForThisView(facesContext, root) &&
              (PhaseId.INVOKE_APPLICATION.equals(facesContext.getCurrentPhaseId()) ||
              PhaseId.APPLY_REQUEST_VALUES.equals(facesContext.getCurrentPhaseId())) )
         {
             NavigationHandler navigationHandler = application.getNavigationHandler();
             if (navigationHandler instanceof ConfigurableNavigationHandler)
             {
                 NavigationCase navigationCase = ((ConfigurableNavigationHandler) navigationHandler).
                     getNavigationCase(facesContext, fromAction, outcome);
                 if (navigationCase != null)
                 {
                     // Deferred invoke navigation. The first one wins
                     if (!facesContext.getAttributes().containsKey(ViewPoolProcessor.INVOKE_DEFERRED_NAVIGATION))
                     {
                         String toFlowDocumentId = (component != null) ? 
                             (String) component.getAttributes().get(ActionListener.TO_FLOW_DOCUMENT_ID_ATTR_NAME) : null;
                         if (toFlowDocumentId != null)
                         {
                             facesContext.getAttributes().put(ViewPoolProcessor.INVOKE_DEFERRED_NAVIGATION, 
                                     new Object[]{fromAction, outcome, toFlowDocumentId});
                         }
                         else
                         {
                             facesContext.getAttributes().put(ViewPoolProcessor.INVOKE_DEFERRED_NAVIGATION, 
                                     new Object[]{fromAction, outcome});
                         }
                     }
                 }
             }
         }
         else
         {
             NavigationHandler navigationHandler = application.getNavigationHandler();
             String toFlowDocumentId = (component != null) ? 
                 (String) component.getAttributes().get(ActionListener.TO_FLOW_DOCUMENT_ID_ATTR_NAME) : null;
 
             if (toFlowDocumentId != null)
             {
                 navigationHandler.handleNavigation(facesContext, fromAction, outcome, toFlowDocumentId);
             }
             else
             {
                 navigationHandler.handleNavigation(facesContext, fromAction, outcome);
             }
             //Render Response if needed
             facesContext.renderResponse();
         }
     }
 }