/*
    * 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.trinidad.event;
  
  import javax.el.ValueExpression;
  
  import javax.faces.component.StateHolder;
  import javax.faces.context.FacesContext;
  import javax.faces.event.ActionEvent;
  import javax.faces.event.ActionListener;
  
  import org.apache.myfaces.trinidad.bean.FacesBean;
  import org.apache.myfaces.trinidad.bean.FacesBeanImpl;
  import org.apache.myfaces.trinidad.bean.PropertyKey;
  import org.apache.myfaces.trinidad.logging.TrinidadLogger;
  
  /**
   * ActionListener that supports getting a value from
   * one binding and setting it on another.
   */
  public class SetActionListener implements ActionListener, StateHolder
  {
    /**
     * Creates a SetActionListener.
     */
    public SetActionListener()
    {
      _bean = new Bean();
    }
  
    /**
     * Gets the value from the "from" property and sets it on 
     * the ValueBinding for the "to" property
     */
    public void processAction(ActionEvent event)
    {
      ValueExpression to = _bean.getValueExpression(Bean.TO_KEY);
      if (to != null)
      {
        Object from = getFrom();
        try
        {
          to.setValue(FacesContext.getCurrentInstance().getELContext(), from);
        }
        catch (RuntimeException e)
        {
          if (_LOG.isWarning())
          {
            ValueExpression fromExpression = _bean.getValueExpression(Bean.FROM_KEY);
            String mes = "Error setting:'"+to.getExpressionString() +
              "' to value:"+from;
            if (fromExpression != null)
              mes += " from:'"+fromExpression.getExpressionString()+"'";
              
            _LOG.warning(mes, e);
          }
          throw e;
        }
      }
    }
  
    public ValueExpression getValueExpression(String name)
    {
      PropertyKey key = Bean.TYPE.findKey(name);
      if (key == null)
        return null;
  
      return _bean.getValueExpression(key);
    }
  
    public void setValueExpression(String name, ValueExpression binding)
    {
      PropertyKey key = Bean.TYPE.findKey(name);
      if (key == null)
        throw new IllegalArgumentException();
      _bean.setValueExpression(key, binding);
    }
  
    public Object getFrom()
    {
      return _bean.getProperty(Bean.FROM_KEY);
    }
  
   public void setFrom(Object from)
   {
     _bean.setProperty(Bean.FROM_KEY, from);
   }
 
   public Object saveState(FacesContext context)
   {
     return _bean.saveState(context);
   }
 
   public void restoreState(FacesContext context, Object state)
   {
     _bean.restoreState(context, state);
   }
 
   public boolean isTransient()
   {
     return false;
   }
 
   public void setTransient(boolean newTransientValue)
   {
     throw new UnsupportedOperationException();
   }
 
   // saveState() and restoreState() come from FacesBeanImpl
   static private class Bean extends FacesBeanImpl
   {
     static public final FacesBean.Type TYPE = new FacesBean.Type();
     static public final PropertyKey FROM_KEY =
       TYPE.registerKey("from");
     // Must be a ValueExpression
     static public final PropertyKey TO_KEY =
       TYPE.registerKey("to");
 
 
     @Override
     public Type getType()
     {
       return TYPE;
     }
 
     static
     {
       TYPE.lock();
     }
   }
 
   private Bean _bean;
 
   private static final TrinidadLogger _LOG = TrinidadLogger.createTrinidadLogger(SetActionListener.class);
 }