/*
    * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
    *
    * This code is free software; you can redistribute it and/or modify it
    * under the terms of the GNU General Public License version 2 only, as
    * published by the Free Software Foundation.  Oracle designates this
    * particular file as subject to the "Classpath" exception as provided
    * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package com.sun.jmx.mbeanserver;
  
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.lang.reflect.Type;
  import java.util.WeakHashMap;
  import javax.management.Descriptor;
  import javax.management.ImmutableDescriptor;
  import javax.management.IntrospectionException;
  import javax.management.MBeanAttributeInfo;
  import javax.management.MBeanException;
  import javax.management.MBeanOperationInfo;
  import javax.management.NotCompliantMBeanException;
  import javax.management.NotificationBroadcaster;
  import javax.management.NotificationBroadcasterSupport;
  
  /**
   * @since 1.6
   */
  class StandardMBeanIntrospector extends MBeanIntrospector<Method> {
      private static final StandardMBeanIntrospector instance =
          new StandardMBeanIntrospector();
  
      static StandardMBeanIntrospector getInstance() {
          return instance;
      }
  
      @Override
      PerInterfaceMap<Method> getPerInterfaceMap() {
          return perInterfaceMap;
      }
  
      @Override
      MBeanInfoMap getMBeanInfoMap() {
          return mbeanInfoMap;
      }
  
      @Override
      MBeanAnalyzer<Method> getAnalyzer(Class<?> mbeanInterface)
              throws NotCompliantMBeanException {
          return MBeanAnalyzer.analyzer(mbeanInterface, this);
      }
  
      @Override
      boolean isMXBean() {
          return false;
      }
  
      @Override
      Method mFrom(Method m) {
          return m;
      }
  
      @Override
      String getName(Method m) {
          return m.getName();
      }
  
      @Override
      Type getGenericReturnType(Method m) {
          return m.getGenericReturnType();
      }
  
      @Override
      Type[] getGenericParameterTypes(Method m) {
          return m.getGenericParameterTypes();
      }
  
      @Override
      String[] getSignature(Method m) {
          Class<?>[] params = m.getParameterTypes();
          String[] sig = new String[params.length];
          for (int i = 0; i < params.length; i++)
              sig[i] = params[i].getName();
         return sig;
     }
 
     @Override
     void checkMethod(Method m) {
     }
 
     @Override
     Object invokeM2(Method m, Object target, Object[] args, Object cookie)
             throws InvocationTargetException, IllegalAccessException,
                    MBeanException {
         return m.invoke(target, args);
     }
 
     @Override
     boolean validParameter(Method m, Object value, int paramNo, Object cookie) {
         return isValidParameter(m, value, paramNo);
     }
 
     @Override
     MBeanAttributeInfo getMBeanAttributeInfo(String attributeName,
             Method getter, Method setter) {
 
         final String description = "Attribute exposed for management";
         try {
             return new MBeanAttributeInfo(attributeName, description,
                                           getter, setter);
         } catch (IntrospectionException e) {
             throw new RuntimeException(e); // should not happen
         }
     }
 
     @Override
     MBeanOperationInfo getMBeanOperationInfo(String operationName,
             Method operation) {
         final String description = "Operation exposed for management";
         return new MBeanOperationInfo(description, operation);
     }
 
     @Override
     Descriptor getBasicMBeanDescriptor() {
         /* We don't bother saying mxbean=false, and we can't know whether
            the info is immutable until we know whether the MBean class
            (not interface) is a NotificationBroadcaster. */
         return ImmutableDescriptor.EMPTY_DESCRIPTOR;
     }
 
     @Override
     Descriptor getMBeanDescriptor(Class<?> resourceClass) {
         boolean immutable = isDefinitelyImmutableInfo(resourceClass);
         return new ImmutableDescriptor("mxbean=false",
                                        "immutableInfo=" + immutable);
     }
 
     /* Return true if and only if we can be sure that the given MBean implementation
      * class has immutable MBeanInfo.  A Standard MBean that is a
      * NotificationBroadcaster is allowed to return different values at
      * different times from its getNotificationInfo() method, which is when
      * we might not know if it is immutable.  But if it is a subclass of
      * NotificationBroadcasterSupport and does not override
      * getNotificationInfo(), then we know it won't change.
      */
     static boolean isDefinitelyImmutableInfo(Class<?> implClass) {
         if (!NotificationBroadcaster.class.isAssignableFrom(implClass))
             return true;
         synchronized (definitelyImmutable) {
             Boolean immutable = definitelyImmutable.get(implClass);
             if (immutable == null) {
                 final Class<NotificationBroadcasterSupport> nbs =
                         NotificationBroadcasterSupport.class;
                 if (nbs.isAssignableFrom(implClass)) {
                     try {
                         Method m = implClass.getMethod("getNotificationInfo");
                         immutable = (m.getDeclaringClass() == nbs);
                     } catch (Exception e) {
                         // Too bad, we'll say no for now.
                         return false;
                     }
                 } else
                     immutable = false;
                 definitelyImmutable.put(implClass, immutable);
             }
             return immutable;
         }
     }
     private static final WeakHashMap<Class<?>, Boolean> definitelyImmutable =
             new WeakHashMap<Class<?>, Boolean>();
 
     private static final PerInterfaceMap<Method>
         perInterfaceMap = new PerInterfaceMap<Method>();
 
     private static final MBeanInfoMap mbeanInfoMap = new MBeanInfoMap();
 }