/*

  * Copyright 2006-2007 The Kuali Foundation

  * 

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  * 

  * 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.kuali.rice.kns.workflow.attribute;

 import java.lang.reflect.Method;

 import java.util.HashMap;

 import net.sf.cglib.proxy.Enhancer;

 import net.sf.cglib.proxy.InvocationHandler;

 import org.kuali.rice.core.web.format.BooleanFormatter;

 import org.kuali.rice.kns.bo.BusinessObject;

 import org.kuali.rice.kns.util.ObjectUtils;

 /**

  * This class provides access to the properties of business objects returned as search results by the WorkflowLookupableImpl.

  * 

  * 

  * @see org.kuali.rice.kew.attribute.WorkflowLookupableImpl

  * @deprecated This will go away once workflow supports simple url integration for custom attribute lookups.

  */

 public class WorkflowLookupableInvocationHandler implements InvocationHandler {

     private BusinessObject proxiedBusinessObject;

     private ClassLoader classLoader;

     private String returnUrl;

     /**

      * Constructs a WorkflowLookupableInvocationHandler.java.

      * 

      * @param proxiedBusinessObject The BusinessObject that this instance is providing access to.

      */

     public WorkflowLookupableInvocationHandler(BusinessObject proxiedBusinessObject, ClassLoader classLoader) {

         this.proxiedBusinessObject = proxiedBusinessObject;

         this.classLoader = classLoader;

     }

     /**

      * Constructs a WorkflowLookupableInvocationHandler.java.

      * 

      * @param proxiedBusinessObject The BusinessObject that this instance is providing access to.

      * @param returnUrl The returnUrl String for selection of a result from the UI

      */

     public WorkflowLookupableInvocationHandler(BusinessObject proxiedBusinessObject, String returnUrl, ClassLoader classLoader) {

         this.proxiedBusinessObject = proxiedBusinessObject;

         this.returnUrl = returnUrl;

         this.classLoader = classLoader;

     }

     /**

      * This method intercepts "getReturnUrl" and returns this objects returnUrl attribute. It proxies access to nested

      * BusinessObjects to ensure that the application plugin classloader is used to resolve OJB proxies. And, it translates booleans

      * for the UI, using the BooleanFormatter.

      * 

      * @see net.sf.cglib.proxy.InvocationHandler#invoke(java.lang.Object proxy, java.lang.reflect.Method method, java.lang.Object[]

      *      args)

      * 

      */

     public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

         ClassLoader oldClassloader = Thread.currentThread().getContextClassLoader();

         try {

             Thread.currentThread().setContextClassLoader(classLoader);

             if ("getReturnUrl".equals(method.getName())) {

                 return returnUrl;

             }

             else if ("getWorkflowLookupableResult".equals(method.getName())) {

                 return Enhancer.create(HashMap.class, new Class[] { WorkflowLookupableResult.class }, this);

             }

             else if ("get".equals(method.getName())) {

                 Object propertyValue = ObjectUtils.getNestedValue(proxiedBusinessObject, args[0].toString());

                 if (propertyValue instanceof BusinessObject) {

                     return Enhancer.create(propertyValue.getClass(), new WorkflowLookupableInvocationHandler((BusinessObject) propertyValue, classLoader));

                 }

                 else {

                     if (propertyValue instanceof Boolean) {

                         return new BooleanFormatter().format(propertyValue);

                     }

                     return propertyValue;

                 }

             }

             else {

                 return method.invoke(proxiedBusinessObject, args);

             }

         }

         catch (Exception e) {

             throw (e.getCause() != null ? e.getCause() : e);

         }

         finally {

             Thread.currentThread().setContextClassLoader(oldClassloader);

         }

     }

 }