/*************************************************
    * Copyright (c) Shen Li. All rights reserved.  *
    * http://joyaop.sourceforge.net                *
    * -------------------------------------------- *
    * Distributable under LGPL license.            *
    * See terms of license at gnu.org.             *
    ************************************************/
   package net.sf.joyaop.impl;
   
  import net.sf.cglib.proxy.MethodProxy;
  import net.sf.joyaop.AbstractInterceptor;
  import net.sf.joyaop.AspectRuntimeException;
  import org.aopalliance.intercept.MethodInvocation;
  
  import java.lang.reflect.AccessibleObject;
  import java.lang.reflect.Method;
  import java.util.List;
  
  /***
   * @author Shen Li
   */
  public class InvocationImpl implements AbstractInterceptor, MethodInvocation {
      // If always using per-method InvocationHandler,
      // the Invocation could just contain 3 states: handler, arguments, currentInterceptorIndex
  
      // the target instance and interceptor instances are not in the same list
      // because i want reuse the interceptor list when it contains no instance-scope interceptor
  
      private static final ThreadLocal invocationHolder = new ThreadLocal();
      private static final short INITIAL_INDEX = -1;
  
      private Object[] arguments;
      private short currentInterceptorIndex = INITIAL_INDEX;
      private List interceptorAspectInstances;
      private RuntimeInstance targetInstance;
      private Method method;
      private MethodProxy methodProxy;
      private Object proxy;
  
      public static InvocationImpl getCurrentInvocation() {
          return (InvocationImpl) invocationHolder.get();
      }
  
      public static void setCurrentInvocation(InvocationImpl invocation) {
          invocationHolder.set(invocation);
      }
  
      public Object proceed() throws Throwable {
          currentInterceptorIndex++;
          try {
              return getCurrentRuntimeInstance().invoke(this);
          } finally {
              currentInterceptorIndex--;
          }
      }
  
      public Object execute() throws Throwable {
          throw new AspectRuntimeException(
                  "Method execute() of interface "
                  + AbstractInterceptor.class.getName()
                  + " has not been implemented.");
      }
  
      public boolean isDirty() {
          return (currentInterceptorIndex != INITIAL_INDEX);
      }
  
      private RuntimeInstance getCurrentRuntimeInstance() {
  //        if (!isDirty()) {
  //            throw new AspectRuntimeException("The invocation has not been used.");
  //        }
          if (currentInterceptorIndex < interceptorAspectInstances.size()) {
              return (RuntimeInstance) interceptorAspectInstances.get(currentInterceptorIndex);
          }
          return targetInstance;
      }
  
      public Object getParameter(String name) {
          return getCurrentRuntimeInstance().getParameter(name);
      }
  
      public boolean isOnInterceptor() {
          return (currentInterceptorIndex < interceptorAspectInstances.size());
      }
  
      public boolean allowRecursion() {
          return getCurrentRuntimeInstance().allowRecursiveInvocation();
      }
  
      public Object[] getArguments() {
          return arguments;
      }
  
      public short getCurrentInterceptorIndex() {
          return currentInterceptorIndex;
      }
  
      public List getInterceptorAspectInstances() {
          return interceptorAspectInstances;
     }
 
     public RuntimeInstance getTargetInstance() {
         return targetInstance;
     }
 
     public Method getMethod() {
         return method;
     }
 
     public MethodProxy getMethodProxy() {
         return methodProxy;
     }
 
     public Object getProxy() {
         return proxy;
     }
 
     public Object getThis() {
         return getProxy();
     }
 
     public AccessibleObject getStaticPart() {
         return getMethod();
     }
 
     public void setArguments(Object[] arguments) {
         this.arguments = arguments;
     }
 
     public void setCurrentInterceptorIndex(short currentInterceptorIndex) {
         this.currentInterceptorIndex = currentInterceptorIndex;
     }
 
     public void resetCurrentInterceptorIndex() {
         this.currentInterceptorIndex = INITIAL_INDEX;
     }
 
     public void setInterceptorAspectInstances(List interceptorAspectInstances) {
         this.interceptorAspectInstances = interceptorAspectInstances;
     }
 
     public void setTargetInstance(RuntimeInstance targetInstance) {
         this.targetInstance = targetInstance;
     }
 
     public void setMethod(Method method) {
         this.method = method;
     }
 
     public void setMethodProxy(MethodProxy methodProxy) {
         this.methodProxy = methodProxy;
     }
 
     public void setProxy(Object proxy) {
         this.proxy = proxy;
     }
 }