/*
 * Copyright (c) 2005, 2006, 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.annotation.Annotation;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import javax.management.Descriptor;
import javax.management.ImmutableDescriptor;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanException;
import javax.management.MBeanOperationInfo;
import javax.management.MBeanParameterInfo;
import javax.management.NotCompliantMBeanException;
import javax.management.openmbean.OpenMBeanAttributeInfoSupport;
import javax.management.openmbean.OpenMBeanOperationInfoSupport;
import javax.management.openmbean.OpenMBeanParameterInfo;
import javax.management.openmbean.OpenMBeanParameterInfoSupport;
import javax.management.openmbean.OpenType;

Introspector for MXBeans.  There is exactly one instance of this class.
Since:
1.6/**
 * Introspector for MXBeans.  There is exactly one instance of this class.
 *
 * @since 1.6
 */
class MXBeanIntrospector extends MBeanIntrospector<ConvertingMethod> {
    private static final MXBeanIntrospector instance = new MXBeanIntrospector();

    static MXBeanIntrospector getInstance() {
        return instance;
    }

    @Override
    PerInterfaceMap<ConvertingMethod> getPerInterfaceMap() {
        return perInterfaceMap;
    }

    @Override
    MBeanInfoMap getMBeanInfoMap() {
        return mbeanInfoMap;
    }

    @Override
    MBeanAnalyzer<ConvertingMethod> getAnalyzer(Class<?> mbeanInterface)
            throws NotCompliantMBeanException {
        return MBeanAnalyzer.analyzer(mbeanInterface, this);
    }

    @Override
    boolean isMXBean() {
        return true;
    }

    @Override
    ConvertingMethod mFrom(Method m) {
        return ConvertingMethod.from(m);
    }

    @Override
    String getName(ConvertingMethod m) {
        return m.getName();
    }

    @Override
    Type getGenericReturnType(ConvertingMethod m) {
        return m.getGenericReturnType();
    }

    @Override
    Type[] getGenericParameterTypes(ConvertingMethod m) {
        return m.getGenericParameterTypes();
    }

    @Override
    String[] getSignature(ConvertingMethod m) {
        return m.getOpenSignature();
    }

    @Override
    void checkMethod(ConvertingMethod m) {
        m.checkCallFromOpen();
    }

    @Override
    Object invokeM2(ConvertingMethod m, Object target, Object[] args,
                    Object cookie)
            throws InvocationTargetException, IllegalAccessException,
                   MBeanException {
        return m.invokeWithOpenReturn((MXBeanLookup) cookie, target, args);
    }

    @Override
    boolean validParameter(ConvertingMethod m, Object value, int paramNo,
                           Object cookie) {
        if (value == null) {
            // Null is a valid value for all OpenTypes, even though
            // OpenType.isValue(null) will return false.  It can always be
            // matched to the corresponding Java type, except when that
            // type is primitive.
            Type t = m.getGenericParameterTypes()[paramNo];
            return (!(t instanceof Class) || !((Class) t).isPrimitive());
        } else {
            Object v;
            try {
                v = m.fromOpenParameter((MXBeanLookup) cookie, value, paramNo);
            } catch (Exception e) {
                // Ignore the exception and let MBeanIntrospector.invokeSetter()
                // throw the initial exception.
                return true;
            }
            return isValidParameter(m.getMethod(), v, paramNo);
        }
    }

    @Override
    MBeanAttributeInfo getMBeanAttributeInfo(String attributeName,
            ConvertingMethod getter, ConvertingMethod setter) {

        final boolean isReadable = (getter != null);
        final boolean isWritable = (setter != null);
        final boolean isIs = isReadable && getName(getter).startsWith("is");

        final String description = attributeName;

        final OpenType<?> openType;
        final Type originalType;
        if (isReadable) {
            openType = getter.getOpenReturnType();
            originalType = getter.getGenericReturnType();
        } else {
            openType = setter.getOpenParameterTypes()[0];
            originalType = setter.getGenericParameterTypes()[0];
        }
        Descriptor descriptor = typeDescriptor(openType, originalType);
        if (isReadable) {
            descriptor = ImmutableDescriptor.union(descriptor,
                    getter.getDescriptor());
        }
        if (isWritable) {
            descriptor = ImmutableDescriptor.union(descriptor,
                    setter.getDescriptor());
        }

        final MBeanAttributeInfo ai;
        if (canUseOpenInfo(originalType)) {
            ai = new OpenMBeanAttributeInfoSupport(attributeName,
                                                   description,
                                                   openType,
                                                   isReadable,
                                                   isWritable,
                                                   isIs,
                                                   descriptor);
        } else {
            ai = new MBeanAttributeInfo(attributeName,
                                        originalTypeString(originalType),
                                        description,
                                        isReadable,
                                        isWritable,
                                        isIs,
                                        descriptor);
        }
        // could also consult annotations for defaultValue,
        // minValue, maxValue, legalValues

        return ai;
    }

    @Override
    MBeanOperationInfo getMBeanOperationInfo(String operationName,
            ConvertingMethod operation) {
        final Method method = operation.getMethod();
        final String description = operationName;
        /* Ideally this would be an empty string, but
           OMBOperationInfo constructor forbids that.  Also, we
           could consult an annotation to get a useful
           description.  */

        final int impact = MBeanOperationInfo.UNKNOWN;

        final OpenType<?> returnType = operation.getOpenReturnType();
        final Type originalReturnType = operation.getGenericReturnType();
        final OpenType<?>[] paramTypes = operation.getOpenParameterTypes();
        final Type[] originalParamTypes = operation.getGenericParameterTypes();
        final MBeanParameterInfo[] params =
            new MBeanParameterInfo[paramTypes.length];
        boolean openReturnType = canUseOpenInfo(originalReturnType);
        boolean openParameterTypes = true;
        Annotation[][] annots = method.getParameterAnnotations();
        for (int i = 0; i < paramTypes.length; i++) {
            final String paramName = "p" + i;
            final String paramDescription = paramName;
            final OpenType<?> openType = paramTypes[i];
            final Type originalType = originalParamTypes[i];
            Descriptor descriptor =
                typeDescriptor(openType, originalType);
            descriptor = ImmutableDescriptor.union(descriptor,
                    Introspector.descriptorForAnnotations(annots[i]));
            final MBeanParameterInfo pi;
            if (canUseOpenInfo(originalType)) {
                pi = new OpenMBeanParameterInfoSupport("p" + i,
                                                       paramDescription,
                                                       openType,
                                                       descriptor);
            } else {
                openParameterTypes = false;
                pi = new MBeanParameterInfo(
                    "p" + i,
                    originalTypeString(originalType),
                    paramDescription,
                    descriptor);
            }
            params[i] = pi;
        }

        Descriptor descriptor =
            typeDescriptor(returnType, originalReturnType);
        descriptor = ImmutableDescriptor.union(descriptor,
                Introspector.descriptorForElement(method));
        final MBeanOperationInfo oi;
        if (openReturnType && openParameterTypes) {
            /* If the return value and all the parameters can be faithfully
             * represented as OpenType then we return an OpenMBeanOperationInfo.
             * If any of them is a primitive type, we can't.  Compatibility
             * with JSR 174 means that we must return an MBean*Info where
             * the getType() is the primitive type, not its wrapped type as
             * we would get with an OpenMBean*Info.  The OpenType is available
             * in the Descriptor in either case.
             */
            final OpenMBeanParameterInfo[] oparams =
                new OpenMBeanParameterInfo[params.length];
            System.arraycopy(params, 0, oparams, 0, params.length);
            oi = new OpenMBeanOperationInfoSupport(operationName,
                                                   description,
                                                   oparams,
                                                   returnType,
                                                   impact,
                                                   descriptor);
        } else {
            oi = new MBeanOperationInfo(operationName,
                                        description,
                                        params,
                                        openReturnType ?
                                        returnType.getClassName() :
                                        originalTypeString(originalReturnType),
                                        impact,
                                        descriptor);
        }

        return oi;
    }

    @Override
    Descriptor getBasicMBeanDescriptor() {
        return new ImmutableDescriptor("mxbean=true",
                                       "immutableInfo=true");
    }

    @Override
    Descriptor getMBeanDescriptor(Class<?> resourceClass) {
        /* We already have immutableInfo=true in the Descriptor
         * included in the MBeanInfo for the MXBean interface.  This
         * method is being called for the MXBean *class* to add any
         * new items beyond those in the interface Descriptor, which
         * currently it does not.
         */
        return ImmutableDescriptor.EMPTY_DESCRIPTOR;
    }

    private static Descriptor typeDescriptor(OpenType openType,
                                             Type originalType) {
        return new ImmutableDescriptor(
            new String[] {"openType",
                          "originalType"},
            new Object[] {openType,
                          originalTypeString(originalType)});
    }

    
True if this type can be faithfully represented in an
OpenMBean*Info.
Compatibility with JSR 174 means that primitive types must be
represented by an MBean*Info whose getType() is the primitive type
string, e.g. "int".  If we used an OpenMBean*Info then this string
would be the wrapped type, e.g. "java.lang.Integer".
Compatibility with JMX 1.2 (including J2SE 5.0) means that arrays
of primitive types cannot use an ArrayType representing an array of
primitives, because that didn't exist in JMX 1.2.
/**
     * <p>True if this type can be faithfully represented in an
     * OpenMBean*Info.</p>
     *
     * <p>Compatibility with JSR 174 means that primitive types must be
     * represented by an MBean*Info whose getType() is the primitive type
     * string, e.g. "int".  If we used an OpenMBean*Info then this string
     * would be the wrapped type, e.g. "java.lang.Integer".</p>
     *
     * <p>Compatibility with JMX 1.2 (including J2SE 5.0) means that arrays
     * of primitive types cannot use an ArrayType representing an array of
     * primitives, because that didn't exist in JMX 1.2.</p>
     */
    private static boolean canUseOpenInfo(Type type) {
        if (type instanceof GenericArrayType) {
            return canUseOpenInfo(
                ((GenericArrayType) type).getGenericComponentType());
        } else if (type instanceof Class && ((Class<?>) type).isArray()) {
            return canUseOpenInfo(
                ((Class<?>) type).getComponentType());
        }
        return (!(type instanceof Class && ((Class<?>) type).isPrimitive()));
    }

    private static String originalTypeString(Type type) {
        if (type instanceof Class)
            return ((Class) type).getName();
        else
            return type.toString();
    }

    private static final PerInterfaceMap<ConvertingMethod>
        perInterfaceMap = new PerInterfaceMap<ConvertingMethod>();

    private static final MBeanInfoMap mbeanInfoMap = new MBeanInfoMap();
}