/*
    * 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 javax.faces.component;
  
  import javax.el.ValueExpression;
  import javax.faces.FacesException;
  import javax.faces.context.FacesContext;
  import javax.faces.convert.Converter;
  import javax.faces.convert.ConverterException;
  import java.lang.reflect.Array;
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * The util methods in this class are shared between the javax.faces.component package and
   * the org.apache.myfaces.renderkit package.
   * Please note: Any changes here must also apply to the class in the other package!
   *
   * @author Manfred Geiler (latest modification by $Author: skitching $)
   * @version $Revision: 676298 $ $Date: 2008-07-13 05:31:48 -0500 (Sun, 13 Jul 2008) $
   */
  class _SharedRendererUtils
  {
      static Converter findUIOutputConverter(FacesContext facesContext, UIOutput component)
      {
          // Attention!
          // This code is duplicated in jsfapi component package.
          // If you change something here please do the same in the other class!
  
          Converter converter = component.getConverter();
          if (converter != null) return converter;
  
          //Try to find out by value expression
          ValueExpression expression = component.getValueExpression("value");
          if (expression == null) return null;
  
          Class valueType = expression.getType(facesContext.getELContext());
          if (valueType == null) return null;
  
          if (Object.class.equals(valueType)) return null;    //There is no converter for Object class
  
          try
          {
              return facesContext.getApplication().createConverter(valueType);
          }
          catch (FacesException e)
          {
              log(facesContext, "No Converter for type " + valueType.getName() + " found", e);
              return null;
          }
      }
  
      static Object getConvertedUISelectManyValue(FacesContext facesContext,
                                                  UISelectMany component,
                                                  String[] submittedValue)
              throws ConverterException
      {
          // Attention!
          // This code is duplicated in jsfapi component package.
          // If you change something here please do the same in the other class!
  
          if (submittedValue == null) throw new NullPointerException("submittedValue");
  
          ValueExpression expression = component.getValueExpression("value");
          Class valueType = null;
          Class arrayComponentType = null;
          if (expression != null)
          {
              //By some strange reason vb.getType(facesContext.getELContext());
              //does not return the same as vb.getValue(facesContext.getELContext()).getClass(),
              //so we need to use this instead.
              Object value = expression.getValue(facesContext.getELContext()); 
              valueType = (value != null) ? value.getClass() :
                  expression.getType(facesContext.getELContext()) ;
              
              if (valueType != null && valueType.isArray())
              {
                  arrayComponentType = valueType.getComponentType();
              }
          }
  
          Converter converter = component.getConverter();
          if (converter == null)
         {
             if (valueType == null)
             {
                 // No converter, and no idea of expected type
                 // --> return the submitted String array
                 return submittedValue;
             }
 
             if (List.class.isAssignableFrom(valueType))
             {
                 // expected type is a List
                 // --> according to javadoc of UISelectMany we assume that the element type
                 //     is java.lang.String, and copy the String array to a new List
                 int len = submittedValue.length;
                 List lst = new ArrayList(len);
                 for (int i = 0; i < len; i++)
                 {
                     lst.add(submittedValue[i]);
                 }
                 return lst;
             }
 
             if (arrayComponentType == null)
             {
                 throw new IllegalArgumentException("ValueBinding for UISelectMany must be of type List or Array");
             }
 
             if (Object.class.equals(arrayComponentType)) return submittedValue; //No conversion for Object class
 
             converter = facesContext.getApplication().createConverter(arrayComponentType);
 
             if (converter == null)
             {
                 return submittedValue;
             }
         }
 
         // Now, we have a converter...
         // We determine the type of the component array after converting one of it's elements
         if (expression != null)
         {
             valueType = expression.getType(facesContext.getELContext());
             if (valueType != null && valueType.isArray())
             {
                 if (submittedValue.length > 0)
                 {
                     arrayComponentType = converter.getAsObject(facesContext, component, submittedValue[0]).getClass();
                 }
             }
         }
 
         if (valueType == null)
         {
             // ...but have no idea of expected type
             // --> so let's convert it to an Object array
             int len = submittedValue.length;
             Object [] convertedValues = (Object []) Array.newInstance(
                     arrayComponentType==null?Object.class:arrayComponentType,len);
             for (int i = 0; i < len; i++)
             {
                 convertedValues[i]
                     = converter.getAsObject(facesContext, component, submittedValue[i]);
             }
             return convertedValues;
         }
 
         if (List.class.isAssignableFrom(valueType))
         {
             // Curious case: According to specs we should assume, that the element type
             // of this List is java.lang.String. But there is a Converter set for this
             // component. Because the user must know what he is doing, we will convert the values.
             int len = submittedValue.length;
             List lst = new ArrayList(len);
             for (int i = 0; i < len; i++)
             {
                 lst.add(converter.getAsObject(facesContext, component, submittedValue[i]));
             }
             return lst;
         }
 
         if (arrayComponentType == null)
         {
             throw new IllegalArgumentException("ValueBinding for UISelectMany must be of type List or Array");
         }
 
         if (arrayComponentType.isPrimitive())
         {
             //primitive array
             int len = submittedValue.length;
             Object convertedValues = Array.newInstance(arrayComponentType, len);
             for (int i = 0; i < len; i++)
             {
                 Array.set(convertedValues, i,
                           converter.getAsObject(facesContext, component, submittedValue[i]));
             }
             return convertedValues;
         }
 
         //Object array
         int len = submittedValue.length;
         ArrayList convertedValues = new ArrayList(len);
         for (int i = 0; i < len; i++)
         {
             convertedValues.add(i, converter.getAsObject(facesContext, component, submittedValue[i]));
         }
         return convertedValues.toArray((Object[]) Array.newInstance(arrayComponentType, len));
     }
 
     /**
      * This method is different in the two versions of _SharedRendererUtils.
      */
     private static void log(FacesContext context, String msg, Exception e)
     {
         context.getExternalContext().log(msg, e);
     }
 }