/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 2001-2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Axis" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.axis.encoding.ser;

import org.apache.axis.Constants;
import org.apache.axis.encoding.Deserializer;
import org.apache.axis.encoding.DeserializerFactory;

import javax.xml.namespace.QName;
import javax.xml.rpc.JAXRPCException;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Iterator;
import java.util.Vector;

/**
 * Base class for Axis Deserialization Factory classes for code reuse
 *
 * @author Rich Scheuerle <scheu@us.ibm.com>
 */
public abstract class BaseDeserializerFactory extends BaseFactory
        implements DeserializerFactory
{

   transient static Vector mechanisms = null;

   protected Class deserClass = null;
   protected QName xmlType = null;
   protected Class javaType = null;

   transient protected Constructor deserClassConstructor = null;
   transient protected Method getDeserializer = null;

   /**
    * Constructor
    *
    * @param deserClass is the class of the Deserializer
    */
   public BaseDeserializerFactory(Class deserClass)
   {
      this.deserClass = deserClass;
      this.mechanisms = new Vector();
      this.mechanisms.add(Constants.AXIS_SAX);
   }

   public BaseDeserializerFactory(Class deserClass,
                                  QName xmlType,
                                  Class javaType)
   {
      this(deserClass);
      this.xmlType = xmlType;
      this.javaType = javaType;
   }

   public javax.xml.rpc.encoding.Deserializer
           getDeserializerAs(String mechanismType)
           throws JAXRPCException
   {
      Deserializer deser = null;

      // Need to add code to check against mechanisms vector.

      // Try getting a specialized Deserializer
      deser = getSpecialized(mechanismType);

      // Try getting a general purpose Deserializer via constructor
      // invocation
      if (deser == null)
      {
         deser = getGeneralPurpose(mechanismType);
      }

      try
      {
         // If not successfull, try newInstance
         if (deser == null)
         {
            deser = (Deserializer)deserClass.newInstance();
         }
      }
      catch (Exception e)
      {
         throw new JAXRPCException(e);
      }
      return deser;
   }

   /**
    * Obtains a deserializer by invoking <constructor>(javaType, xmlType)
    * on the deserClass.
    */
   protected Deserializer getGeneralPurpose(String mechanismType)
   {
      if (javaType != null && xmlType != null)
      {
         Constructor deserClassConstructor = getDeserClassConstructor();
         if (deserClassConstructor != null)
         {
            try
            {
               return (Deserializer)
                       deserClassConstructor.newInstance(new Object[]{javaType, xmlType});
            }
            catch (InstantiationException e)
            {
            }
            catch (IllegalAccessException e)
            {
            }
            catch (InvocationTargetException e)
            {
            }
         }
      }
      return null;
   }

   /**
    * return constructor for class if any
    */
   private Constructor getConstructor(Class clazz)
   {
      try
      {
         return clazz.getConstructor(new Class[]{Class.class, QName.class});
      }
      catch (NoSuchMethodException e)
      {
      }
      return null;
   }

   /**
    * Obtains a deserializer by invoking getDeserializer method in the
    * javaType class or its Helper class.
    */
   protected Deserializer getSpecialized(String mechanismType)
   {
      if (javaType != null && xmlType != null)
      {
         Method getDeserializer = getGetDeserializer();
         if (getDeserializer != null)
         {
            try
            {
               return (Deserializer)
                       getDeserializer.invoke(null,
                               new Object[]{mechanismType,
                                            javaType,
                                            xmlType});
            }
            catch (IllegalAccessException e)
            {
            }
            catch (InvocationTargetException e)
            {
            }
         }
      }
      return null;
   }

   /**
    * Returns a list of all XML processing mechanism types supported by this DeserializerFactory.
    *
    * @return List of unique identifiers for the supported XML processing mechanism types
    */
   public Iterator getSupportedMechanismTypes()
   {
      return mechanisms.iterator();
   }

   /**
    * Utility method that intospects on a factory class to decide how to
    * create the factory.  Tries in the following order:
    * public static create(Class javaType, QName xmlType)
    * public <constructor>(Class javaType, QName xmlType)
    * public <constructor>()
    *
    * @param factory  class
    * @param javaType
    * @param xmlType
    */
   public static DeserializerFactory createFactory(Class factory,
                                                   Class javaType,
                                                   QName xmlType)
   {

      DeserializerFactory df = null;
      try
      {
         Method method =
                 factory.getMethod("create",
                         new Class[]{Class.class, QName.class});
         df = (DeserializerFactory)
                 method.invoke(null,
                         new Object[]{javaType, xmlType});
      }
      catch (NoSuchMethodException e)
      {
      }
      catch (IllegalAccessException e)
      {
      }
      catch (InvocationTargetException e)
      {
      }

      if (df == null)
      {
         try
         {
            Constructor constructor =
                    factory.getConstructor(new Class[]{Class.class, QName.class});
            df = (DeserializerFactory)
                    constructor.newInstance(new Object[]{javaType, xmlType});
         }
         catch (NoSuchMethodException e)
         {
         }
         catch (InstantiationException e)
         {
         }
         catch (IllegalAccessException e)
         {
         }
         catch (InvocationTargetException e)
         {
         }
      }

      if (df == null)
      {
         try
         {
            df = (DeserializerFactory)factory.newInstance();
         }
         catch (InstantiationException e)
         {
         }
         catch (IllegalAccessException e)
         {
         }
      }
      return df;
   }

   /**
    * Returns the deserClassConstructor.
    *
    * @return Constructor
    */
   protected Constructor getDeserClassConstructor()
   {
      if (deserClassConstructor == null)
      {
         deserClassConstructor = getConstructor(deserClass);
      }
      return deserClassConstructor;
   }

   /**
    * Returns the getDeserializer.
    *
    * @return Method
    */
   protected Method getGetDeserializer()
   {
      if (getDeserializer == null)
      {
         getDeserializer = getMethod(javaType, "getDeserializer");
      }
      return getDeserializer;
   }

}
