/*
    * 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.el.convert;
  
  import javax.el.ELException;
  import javax.el.ValueExpression;
  import javax.faces.component.StateHolder;
  import javax.faces.context.FacesContext;
  import javax.faces.el.EvaluationException;
  import javax.faces.el.PropertyNotFoundException;
  import javax.faces.el.ValueBinding;
  
  import org.apache.myfaces.shared_impl.util.ClassUtils;
  
  /**
   * Converter for legacy ValueBinding objects. See JSF 1.2 section 5.8.3
   * 
   * ATTENTION: If you make changes to this class, treat javax.faces.component.ValueExpressionToValueBinding accordingly.
   * 
   * @author Stan Silvert
   * @see javax.faces.component.ValueExpressionToValueBinding
   */
  @SuppressWarnings("deprecation")
  public class ValueExpressionToValueBinding extends ValueBinding implements StateHolder
  {
  
      private ValueExpression _valueExpression;
  
      private boolean isTransient = false;
  
      // required no-arg constructor for StateHolder
      public ValueExpressionToValueBinding()
      {
          _valueExpression = null;
      }
  
      @Override
      public int hashCode()
      {
          int result = 1;
          result = 31 * result + ((_valueExpression == null) ? 0 : _valueExpression.hashCode());
          result = 31 * result + (isTransient ? 1231 : 1237);
          return result;
      }
  
      @Override
      public boolean equals(Object obj)
      {
          if (this == obj)
              return true;
          if (obj == null)
              return false;
          if (getClass() != obj.getClass())
              return false;
          final ValueExpressionToValueBinding other = (ValueExpressionToValueBinding) obj;
          if (_valueExpression == null)
          {
              if (other._valueExpression != null)
                  return false;
          }
          else if (!_valueExpression.equals(other._valueExpression))
              return false;
          if (isTransient != other.isTransient)
              return false;
          return true;
      }
  
      /**
       * @return the valueExpression
       */
      public ValueExpression getValueExpression()
      {
          return getNotNullValueExpression();
      }
  
      /**
       * @return the valueExpression
       */
      private ValueExpression getNotNullValueExpression()
      {
          if (_valueExpression == null)
          {
              throw new IllegalStateException("value expression is null");
         }
         return _valueExpression;
     }
 
     @Override
     public String getExpressionString()
     {
         return getNotNullValueExpression().getExpressionString();
     }
 
     /** Creates a new instance of ValueExpressionToValueBinding */
     public ValueExpressionToValueBinding(ValueExpression valueExpression)
     {
         if (valueExpression == null)
         {
             throw new IllegalArgumentException("value expression must not be null.");
         }
         _valueExpression = valueExpression;
     }
 
     @Override
     public void setValue(FacesContext facesContext, Object value) throws EvaluationException, PropertyNotFoundException
     {
         try
         {
             getNotNullValueExpression().setValue(facesContext.getELContext(), value);
         }
         catch (javax.el.PropertyNotFoundException e)
         {
             throw new javax.faces.el.PropertyNotFoundException(e);
         }
         catch (ELException e)
         {
             throw new EvaluationException(e);
         }
     }
 
     @Override
     public boolean isReadOnly(FacesContext facesContext) throws EvaluationException, PropertyNotFoundException
     {
 
         try
         {
             return getNotNullValueExpression().isReadOnly(facesContext.getELContext());
         }
         catch (javax.el.PropertyNotFoundException e)
         {
             throw new javax.faces.el.PropertyNotFoundException(e);
         }
         catch (ELException e)
         {
             throw new EvaluationException(e);
         }
 
     }
 
     @Override
     public Object getValue(FacesContext facesContext) throws EvaluationException, PropertyNotFoundException
     {
         try
         {
             return getNotNullValueExpression().getValue(facesContext.getELContext());
         }
         catch (javax.el.PropertyNotFoundException e)
         {
             throw new javax.faces.el.PropertyNotFoundException(e);
         }
         catch (ELException e)
         {
             throw new EvaluationException(e);
         }
     }
 
     @Override
     public Class getType(FacesContext facesContext) throws EvaluationException, PropertyNotFoundException
     {
         try
         {
             return getNotNullValueExpression().getType(facesContext.getELContext());
         }
         catch (javax.el.PropertyNotFoundException e)
         {
             throw new javax.faces.el.PropertyNotFoundException(e);
         }
         catch (ELException e)
         {
             throw new EvaluationException(e);
         }
     }
 
     // -------- StateHolder methods -------------------------------------------
 
     public void restoreState(FacesContext facesContext, Object state)
     {
         if (state != null)
         {
             if (state instanceof ValueExpression)
             {
                 _valueExpression = (ValueExpression) state;
             }
             else
             {
                 Object[] stateArray = (Object[]) state;
                 _valueExpression = (ValueExpression) ClassUtils.newInstance((String) stateArray[0], ValueExpression.class);
                 ((StateHolder) _valueExpression).restoreState(facesContext, stateArray[1]);
             }
         }
     }
 
     public Object saveState(FacesContext context)
     {
         if (!isTransient)
         {
             if (_valueExpression instanceof StateHolder)
             {
                 Object[] state = new Object[2];
                 state[0] = _valueExpression.getClass().getName();
                 state[1] = ((StateHolder) _valueExpression).saveState(context);
                 return state;
             }
             else
             {
                 return _valueExpression;
             }
         }
         return null;
     }
 
     public void setTransient(boolean newTransientValue)
     {
         isTransient = newTransientValue;
     }
 
     public boolean isTransient()
     {
         return isTransient;
     }
 
 }