/*

 * Copyright (c) 2005, 2013, 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;

import sun.reflect.misc.MethodUtil;

/**

 * @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 MethodUtil.invoke(m, 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();

}