/*
    * 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.view.facelets.tag.jsf;
  
  import javax.el.MethodExpression;
  import javax.faces.component.ActionSource;
  import javax.faces.component.ActionSource2;
  import javax.faces.event.ActionEvent;
  import javax.faces.event.MethodExpressionActionListener;
  import javax.faces.view.facelets.FaceletContext;
  import javax.faces.view.facelets.MetaRule;
  import javax.faces.view.facelets.Metadata;
  import javax.faces.view.facelets.MetadataTarget;
  import javax.faces.view.facelets.TagAttribute;
  
  import org.apache.myfaces.view.facelets.FaceletCompositionContext;
  import org.apache.myfaces.view.facelets.el.LegacyMethodBinding;
  
  /**
   * 
   * @author Jacob Hookom
   * @version $Id$
   */
  public final class ActionSourceRule extends MetaRule
  {
      public final static Class<?>[] ACTION_SIG = new Class[0];
  
      public final static Class<?>[] ACTION_LISTENER_SIG = new Class<?>[] { ActionEvent.class };
  
      final static class ActionMapper extends Metadata
      {
  
          private final TagAttribute attr;
  
          public ActionMapper(TagAttribute attr)
          {
              this.attr = attr;
          }
  
          public void applyMetadata(FaceletContext ctx, Object instance)
          {
              ((ActionSource) instance).setAction(new LegacyMethodBinding(
                      this.attr.getMethodExpression(ctx, null, ActionSourceRule.ACTION_SIG)));
          }
      }
      
      final static class ActionMapper2 extends Metadata
      {
          private final TagAttribute _attr;
  
          public ActionMapper2(TagAttribute attr)
          {
              this._attr = attr;
          }
  
          public void applyMetadata(FaceletContext ctx, Object instance)
          {
              MethodExpression expr = _attr.getMethodExpression(ctx, null, ActionSourceRule.ACTION_SIG);
              ((ActionSource2) instance).setActionExpression(expr);
          }
      }
  
      final static class ActionListenerMapper extends Metadata
      {
  
          private final TagAttribute attr;
  
          public ActionListenerMapper(TagAttribute attr)
          {
              this.attr = attr;
          }
  
          public void applyMetadata(FaceletContext ctx, Object instance)
          {
              ((ActionSource) instance)
                      .setActionListener(new LegacyMethodBinding(this.attr
                              .getMethodExpression(ctx, null,
                                      ActionSourceRule.ACTION_LISTENER_SIG)));
          }
  
      }
  
      final static class ActionListenerMapper2 extends Metadata
     {
         private final TagAttribute _attr;
 
         public ActionListenerMapper2(TagAttribute attr)
         {
             _attr = attr;
         }
 
         public void applyMetadata(FaceletContext ctx, Object instance)
         {
             // From JSF 2.0 it is possible to have actionListener method without ActionEvent parameter. 
             // It seems that MethodExpressionActionListener from API contains support for it but there is one big
             // problem - one-arg constructor will not preserve the current VariableMapper.
             // This is a problem when using facelets and <ui:decorate/> with EL params (see MYFACES-2541 for details).
             // So we must create two MethodExpressions here - both are created from the current 
             // facelets context and thus varibale mapping will work.
             final MethodExpression methodExpressionOneArg
                     = _attr.getMethodExpression(ctx, null, ActionSourceRule.ACTION_LISTENER_SIG);
             final MethodExpression methodExpressionZeroArg
                     = _attr.getMethodExpression(ctx, null, ActionSourceRule.ACTION_SIG);
             if (FaceletCompositionContext.getCurrentInstance(ctx).isUsingPSSOnThisView())
             {
                 ((ActionSource2) instance).addActionListener(
                         new PartialMethodExpressionActionListener(methodExpressionOneArg, methodExpressionZeroArg));
             }
             else
             {
                 ((ActionSource2) instance).addActionListener(
                         new MethodExpressionActionListener(methodExpressionOneArg, methodExpressionZeroArg));
             }
         }
     }
 
     public final static ActionSourceRule INSTANCE = new ActionSourceRule();
 
     public ActionSourceRule()
     {
         super();
     }
 
     public Metadata applyRule(String name, TagAttribute attribute, MetadataTarget meta)
     {
         if (meta.isTargetInstanceOf(ActionSource.class))
         {
             if ("action".equals(name))
             {
                 if (meta.isTargetInstanceOf(ActionSource2.class))
                 {
                     return new ActionMapper2(attribute);
                 }
                 else
                 {
                     return new ActionMapper(attribute);
                 }
             }
 
             if ("actionListener".equals(name))
             {
                 if (meta.isTargetInstanceOf(ActionSource2.class))
                 {
                     return new ActionListenerMapper2(attribute);
                 }
                 else
                 {
                     return new ActionListenerMapper(attribute);
                 }
             }
         }
         
         return null;
     }
 }