/*
 * Copyright (c) 2007, 2018 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0, which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package org.glassfish.gmbal.impl;

import org.glassfish.gmbal.AMXMetadata;
import java.util.List;
import java.util.Arrays;
import java.util.ArrayList;
import java.util.Map;
import java.util.HashMap;
import java.util.Set;
import java.util.HashSet;
import java.util.Iterator;
import java.util.concurrent.atomic.AtomicLong;

import java.lang.reflect.Method;
import java.lang.reflect.ReflectPermission;

import java.security.AccessController;
import java.security.Permission;
import java.security.PrivilegedAction;
import javax.management.Attribute;
import javax.management.AttributeList;
import javax.management.MBeanException;
import javax.management.InvalidAttributeValueException;
import javax.management.AttributeNotFoundException;
import javax.management.ReflectionException;
import javax.management.MBeanParameterInfo;

import javax.management.NotificationBroadcasterSupport;
import javax.management.AttributeChangeNotification;

import org.glassfish.gmbal.NameValue;
import org.glassfish.gmbal.ManagedOperation;
import org.glassfish.gmbal.ParameterNames;

import javax.management.Descriptor;
import javax.management.JMException;
import javax.management.modelmbean.ModelMBeanAttributeInfo;
import javax.management.modelmbean.ModelMBeanInfoSupport;
import javax.management.modelmbean.ModelMBeanOperationInfo;
import javax.management.openmbean.OpenMBeanParameterInfoSupport;
import org.glassfish.gmbal.impl.trace.TraceRegistration;
import org.glassfish.gmbal.impl.trace.TraceRegistrationFine;
import org.glassfish.gmbal.impl.trace.TraceRuntime;
import org.glassfish.gmbal.typelib.EvaluatedClassAnalyzer;
import org.glassfish.gmbal.typelib.EvaluatedClassDeclaration;
import org.glassfish.gmbal.typelib.EvaluatedFieldDeclaration;
import org.glassfish.gmbal.typelib.EvaluatedMethodDeclaration;
import org.glassfish.gmbal.typelib.EvaluatedType;
import org.glassfish.pfl.basic.algorithm.DumpIgnore;
import org.glassfish.pfl.basic.algorithm.DumpToString;
import org.glassfish.pfl.basic.contain.Pair;
import org.glassfish.pfl.basic.facet.FacetAccessor;
import org.glassfish.pfl.basic.func.BinaryFunction;
import org.glassfish.pfl.tf.spi.annotation.InfoMethod;

@TraceRegistrationFine
@TraceRegistration
@TraceRuntime
public class MBeanSkeleton {
    private static Descriptor DEFAULT_AMX_DESCRIPTOR =
        DescriptorIntrospector.descriptorForElement( null,
            ManagedObjectManagerImpl.DefaultAMXMetadataHolder.class ) ;

    @TraceRuntime
    public interface Operation
	extends BinaryFunction<FacetAccessor, List<Object>, Object> {
    };

    private AMXMetadata mbeanType;
    private final String type;
    private Descriptor descriptor;
    @DumpToString
    private final AtomicLong sequenceNumber;
    @DumpToString
    private final ManagedObjectManagerInternal mom;
    @DumpIgnore
    private final Map<String, AttributeDescriptor> setters;
    private final Map<String, AttributeDescriptor> getters;
    private AttributeDescriptor nameAttributeDescriptor;
    private final Map<String, Map<List<String>, Operation>> operations;
    private final List<ModelMBeanAttributeInfo> mbeanAttributeInfoList;
    private final List<ModelMBeanOperationInfo> mbeanOperationInfoList;
    private final ModelMBeanInfoSupport mbInfo;

    private <K, L, V> void addToCompoundMap(
	Map<K, Map<L, V>> source, Map<K, Map<L, V>> dest) {

	for (Map.Entry<K, Map<L, V>> entry : source.entrySet()) {
	    Map<L, V> dmap = dest.get(entry.getKey());
	    if (dmap == null) {
		dmap = new HashMap<L, V>();
		dest.put(entry.getKey(), dmap);
	    }
	    dmap.putAll(entry.getValue());
	}
    }

    public MBeanSkeleton(final EvaluatedClassDeclaration annotatedClass,
	final EvaluatedClassAnalyzer ca,
	final ManagedObjectManagerInternal mom) {

        boolean isDefaultAMXMetadata = false ;
	mbeanType = mom.getFirstAnnotationOnClass(annotatedClass, AMXMetadata.class);
	if (mbeanType == null) {
            isDefaultAMXMetadata = true ;
	    mbeanType = mom.getDefaultAMXMetadata() ;
	}

	type = mom.getTypeName(annotatedClass.cls(), "AMX_TYPE",
		mbeanType.type());

	Descriptor ldesc = DescriptorIntrospector.descriptorForElement( mom,
	    annotatedClass.cls() ) ;

        if (isDefaultAMXMetadata) {
            // We didn't have an @AMXMetadata annotation on annotatedClass,
            // so we need to construct a new Descriptor that contains the
            // default AMXMetadata values, as well as any other values that
            // may be present from other metadata annotations.
            ldesc = DescriptorUtility.union( DEFAULT_AMX_DESCRIPTOR, ldesc ) ;
        }

        // Now fix up the descriptor so that the ModelMBean code won't
        // complain.
        descriptor = makeValidDescriptor( ldesc, DescriptorType.mbean, type);

	sequenceNumber = new AtomicLong();

	this.mom = mom;

	setters = new HashMap<String, AttributeDescriptor>();
	getters = new HashMap<String, AttributeDescriptor>();
	operations = new HashMap<String, Map<List<String>, Operation>>();
	mbeanAttributeInfoList = new ArrayList<ModelMBeanAttributeInfo>();
	mbeanOperationInfoList = new ArrayList<ModelMBeanOperationInfo>();

	analyzeAttributes(ca);
	analyzeOperations(ca);
	analyzeObjectNameKeys(ca);

	mbInfo = makeMbInfo(mom.getDescription(annotatedClass));
    }

    // In case of conflicts, always prefer second over first.
    private MBeanSkeleton(MBeanSkeleton first, MBeanSkeleton second) {
	mbeanType = second.mbeanType;

	type = second.type;

	descriptor = DescriptorUtility.union(first.descriptor,
		second.descriptor);

	sequenceNumber = new AtomicLong();

	mom = second.mom;

	setters = new HashMap<String, AttributeDescriptor>();
	setters.putAll(first.setters);
	setters.putAll(second.setters);

	getters = new HashMap<String, AttributeDescriptor>();
	getters.putAll(first.getters);
	getters.putAll(second.getters);

	nameAttributeDescriptor = second.nameAttributeDescriptor;

	operations = new HashMap<String, Map<List<String>, Operation>>();
	addToCompoundMap(first.operations, operations);
	addToCompoundMap(second.operations, operations);

	mbeanAttributeInfoList = new ArrayList<ModelMBeanAttributeInfo>();
	mbeanAttributeInfoList.addAll(first.mbeanAttributeInfoList);
	mbeanAttributeInfoList.addAll(second.mbeanAttributeInfoList);

	mbeanOperationInfoList = new ArrayList<ModelMBeanOperationInfo>();
	mbeanOperationInfoList.addAll(first.mbeanOperationInfoList);
	mbeanOperationInfoList.addAll(second.mbeanOperationInfoList);

	// This must go last, because it depends on some of the
	// preceding initializations.
	mbInfo = makeMbInfo(second.mbInfo.getDescription());
    }

    private ModelMBeanInfoSupport makeMbInfo(String description) {
	ModelMBeanAttributeInfo[] attrInfos = mbeanAttributeInfoList.toArray(
	    new ModelMBeanAttributeInfo[mbeanAttributeInfoList.size()]);
	ModelMBeanOperationInfo[] operInfos = mbeanOperationInfoList.toArray(
	    new ModelMBeanOperationInfo[mbeanOperationInfoList.size()]);

	return new ModelMBeanInfoSupport( type, description, attrInfos, null, 
	    operInfos, null, descriptor);
    }

    
Create a new MBeanSkeleton that is the composition of this one
and skel.  Note that, if this and skel contain the same attribute,
the version from skel will appear in the composition.
/** Create a new MBeanSkeleton that is the composition of this one
     * and skel.  Note that, if this and skel contain the same attribute,
     * the version from skel will appear in the composition.
     */
    public MBeanSkeleton compose(MBeanSkeleton skel) {
	return new MBeanSkeleton(this, skel);
    }

    private enum DescriptorType { mbean, attribute, operation }

    // Create a valid descriptor so that ModelMBinfoSupport won't throw
    // an exception.
    Descriptor makeValidDescriptor(Descriptor desc, DescriptorType dtype,
	String dname) {

	Map<String, Object> map = new HashMap<String, Object>();
	String[] names = desc.getFieldNames();
	Object[] values = desc.getFieldValues((String[]) null);
	for (int ctr = 0; ctr < names.length; ctr++) {
	    map.put(names[ctr], values[ctr]);
	}

	map.put("descriptorType", dtype.toString());
	if (dtype == DescriptorType.operation) {
	    map.put("role", "operation");
	    map.put("targetType", "ObjectReference");
	} else if (dtype == DescriptorType.mbean) {
	    map.put("persistPolicy", "never");
	    map.put("log", "F");
	    map.put("visibility", "1");
	}

	map.put("name", dname);
	map.put("displayName", dname);

	return DescriptorUtility.makeDescriptor(map);
    }

    @Override
    public String toString() {
	return "DynamicMBeanSkeleton[type" + type + "]";
    }

    @InfoMethod
    private void descriptorContents( String name, String description,
        Descriptor desc ) {}

    @InfoMethod
    private void attributeInfoContents( ModelMBeanAttributeInfo info ) {}

    // This method should only be called when getter.id.equals( setter.id )
    @TraceRegistrationFine
    private void processAttribute(AttributeDescriptor getter,
	AttributeDescriptor setter) {

        if ((setter == null) && (getter == null)) {
            throw Exceptions.self.notBothNull();
        }

        if ((setter != null) && (getter != null)
            && !setter.type().equals(getter.type())) {
            throw Exceptions.self.typesMustMatch();
        }

        AttributeDescriptor nonNullDescriptor =
            (getter != null) ? getter : setter;

        String name = nonNullDescriptor.id();
        String description = nonNullDescriptor.description();
        Descriptor desc = DescriptorUtility.EMPTY_DESCRIPTOR;
        if (getter != null) {
            desc = DescriptorUtility.union(desc,
                DescriptorIntrospector.descriptorForElement( mom,
                getter.accessible()));
        }

        if (setter != null) {
            desc = DescriptorUtility.union(desc,
                DescriptorIntrospector.descriptorForElement( mom,
                setter.accessible()));
        }

        desc = makeValidDescriptor(desc, DescriptorType.attribute, name);

        descriptorContents( name, description, desc ) ;

        TypeConverter tc = mom.getTypeConverter(nonNullDescriptor.type());

        ModelMBeanAttributeInfo ainfo = new ModelMBeanAttributeInfo(name,
            tc.getManagedType().getClassName(), description,
            getter != null, setter != null, false, desc);

        attributeInfoContents(ainfo);

        mbeanAttributeInfoList.add(ainfo);
    }

    @InfoMethod
    private void attributes( 
        Pair<Map<String, AttributeDescriptor>,
             Map<String, AttributeDescriptor>> amap ) {}

    @InfoMethod
    private void setterNames( String msg, Set<String> names ) {}

    @TraceRegistrationFine
    private void analyzeAttributes(EvaluatedClassAnalyzer ca) {
        Pair<Map<String, AttributeDescriptor>, Map<String, AttributeDescriptor>> amap =
            mom.getAttributes(ca,
            ManagedObjectManagerInternal.AttributeDescriptorType.MBEAN_ATTR);

        getters.putAll(amap.first());
        setters.putAll(amap.second());

        attributes( amap ) ;

        final Set<String> setterNames = new HashSet<String>(setters.keySet());
        setterNames( "before removing getters", setterNames ) ;

        for (String str : getters.keySet()) {
            processAttribute(getters.get(str), setters.get(str));
            setterNames.remove(str);
        }

        setterNames( "after removing getters", setterNames ) ;

        // Handle setters without getters
        for (String str : setterNames) {
            processAttribute(null, setters.get(str));
        }
    }

    @InfoMethod
    private void annotatedMethod( EvaluatedMethodDeclaration annotatedMethod ) {}

    @TraceRegistrationFine
    private void analyzeObjectNameKeys(EvaluatedClassAnalyzer ca) {
        final List<EvaluatedFieldDeclaration> annotatedFields =
            ca.findFields(mom.forAnnotation(NameValue.class,
            EvaluatedFieldDeclaration.class));

        final List<EvaluatedMethodDeclaration> annotatedMethods =
            ca.findMethods(mom.forAnnotation(NameValue.class,
            EvaluatedMethodDeclaration.class));

        if ((annotatedMethods.size() == 0) && (annotatedFields.size() == 0)) {
            return;
        }

        // If there are two methods with @NameValue in the same
        // class, we have an error.
        EvaluatedMethodDeclaration annotatedMethod = annotatedMethods.get(0);
        if (annotatedMethods.size() > 1) {
            EvaluatedMethodDeclaration second = annotatedMethods.get(1);

            if (annotatedMethod.containingClass().equals(
                second.containingClass())) {

            throw Exceptions.self.duplicateObjectNameKeyAttributes(
                annotatedMethod, second,
                annotatedMethod.containingClass().name());
            }
        }

        annotatedMethod(annotatedMethod);

        nameAttributeDescriptor = AttributeDescriptor.makeFromAnnotated(
            mom, annotatedMethod, "NameValue",
            Exceptions.self.nameOfManagedObject(),
            ManagedObjectManagerInternal.AttributeDescriptorType.MBEAN_ATTR);
    }

    private static final Permission accessControlPermission =
	new ReflectPermission("suppressAccessChecks");

    @InfoMethod
    private void describe( String msg, Object data ) { }

    @TraceRegistrationFine
    private Pair<Operation, ModelMBeanOperationInfo> makeOperation(
	    final EvaluatedMethodDeclaration m) {

	AccessController.doPrivileged(
	    new PrivilegedAction<Method>() {
		public Method run() {
		    m.method().setAccessible(true);
		    return m.method();
		} } ) ;

        final String desc = mom.getDescription(m);
        final EvaluatedType rtype = m.returnType();
        final TypeConverter rtc = rtype == null ? null : mom.getTypeConverter(
            rtype);
        final List<EvaluatedType> atypes = m.parameterTypes();
        final List<TypeConverter> atcs = new ArrayList<TypeConverter>();
        final ManagedOperation mo = mom.getAnnotation(m.element(),
            ManagedOperation.class);

        Descriptor modelDescriptor = makeValidDescriptor(
            DescriptorIntrospector.descriptorForElement(mom, m.element()),
            DescriptorType.operation, m.name());

        for (EvaluatedType ltype : atypes) {
            atcs.add(mom.getTypeConverter(ltype));
        }

        describe( "desc", desc ) ;
        describe( "rtype", rtype );
        describe( "rtc", rtc );
        describe( "atcs", atcs );
        describe( "atypes", atypes );
        describe( "descriptor", descriptor );

        final Operation oper = new Operation() {
            @TraceRuntime
            public Object evaluate(FacetAccessor target, List<Object> args) {
                Object[] margs = new Object[args.size()];
                Iterator<Object> argsIterator = args.iterator();
                Iterator<TypeConverter> tcIterator = atcs.iterator();
                int ctr = 0;
                while (argsIterator.hasNext() && tcIterator.hasNext()) {
                    final Object arg = argsIterator.next();
                    final TypeConverter tc = tcIterator.next();
                    margs[ctr++] = tc.fromManagedEntity(arg);
                }

                describe( "margs before invoke", margs ) ;

                Object result = target.invoke(m.method(), margs);

                describe( "result after invoke", result ) ;

                if (rtc == null) {
                    return null;
                } else {
                    return rtc.toManagedEntity(result);
                }
            }
        };

        final ParameterNames pna = mom.getAnnotation( m.element(),
            ParameterNames.class);
        describe( "pna", pna ) ;

        if (pna != null && pna.value().length != atcs.size()) {
                throw Exceptions.self.parameterNamesLengthBad();
        }

        final MBeanParameterInfo[] paramInfo =
                new OpenMBeanParameterInfoSupport[atcs.size()];
        int ctr = 0;
        for (TypeConverter tc : atcs) {
                String name = "";
                try {
                        name = (pna == null) ? "arg" + ctr : pna.value()[ctr];
                        paramInfo[ctr] = new OpenMBeanParameterInfoSupport(
                                name, Exceptions.self.noDescriptionAvailable(),
                                tc.getManagedType());
                        ctr++;
                } catch (IllegalArgumentException ex) {
                        Exceptions.self.excInOpenParameterInfo(ex, name, m);
                }
        }

        final ModelMBeanOperationInfo operInfo =
            new ModelMBeanOperationInfo(m.name(),
            desc, paramInfo, rtc.getManagedType().getClassName(),
            mo.impact().ordinal(), modelDescriptor);

        describe( "operInfo", operInfo ) ;

        return new Pair<Operation, ModelMBeanOperationInfo>(oper, operInfo);
    }

    @TraceRegistrationFine
    private void analyzeOperations(EvaluatedClassAnalyzer ca) {
        // Scan for all methods annotation with @ManagedOperation,
        // including inherited methods.
        final List<EvaluatedMethodDeclaration> ops = ca.findMethods(mom.forAnnotation(
            ManagedOperation.class, EvaluatedMethodDeclaration.class));
        for (EvaluatedMethodDeclaration m : ops) {
            final Pair<Operation, ModelMBeanOperationInfo> data =
                makeOperation(m);
            final ModelMBeanOperationInfo info = data.second();

            final List<String> dataTypes = new ArrayList<String>();
            for (MBeanParameterInfo pi : info.getSignature()) {
                // Replace recursion marker with the constructed implementation
                dataTypes.add(pi.getType());
            }

            Map<List<String>, Operation> map = operations.get(m.name());
            if (map == null) {
                map = new HashMap<List<String>, Operation>();
                operations.put(m.name(), map);
            }

            // Note that the first occurrence of any method will be the most
            // derived, so if there is already an entry, don't overwrite it.
            mom.putIfNotPresent(map, dataTypes, data.first());

            mbeanOperationInfoList.add(info);
        }
    }

    // The rest of the methods are used in the DynamicMBeanImpl code.
    public String getType() {
        return type;
    }

    public AMXMetadata getMBeanType() {
	return mbeanType;
    }

    @TraceRuntime
    public Object getAttribute(FacetAccessor fa, String name)
	throws AttributeNotFoundException, MBeanException, ReflectionException {

        AttributeDescriptor getter = getters.get(name);
        if (getter == null) {
            throw Exceptions.self.couldNotFindAttribute(name);
        }
        Object result = getter.get(fa);

	return result;
    }

    @TraceRuntime
    public void setAttribute(final NotificationBroadcasterSupport emitter,
	final FacetAccessor fa, final Attribute attribute)
	throws AttributeNotFoundException, InvalidAttributeValueException,
	MBeanException, ReflectionException {

        final String name = attribute.getName();
        final Object value = attribute.getValue();
        final AttributeDescriptor getter = getters.get(name);
        final Object oldValue = (getter == null)
            ? null : getter.get(fa);

        describe( "oldValue", oldValue ) ;

        final AttributeDescriptor setter = setters.get(name);
        if (setter == null) {
            throw Exceptions.self.couldNotFindWritableAttribute(name);
        }

        setter.set(fa, value ) ;

        AttributeChangeNotification notification =
            new AttributeChangeNotification(emitter,
                sequenceNumber.incrementAndGet(),
                System.currentTimeMillis(),
                "Changed attribute " + name, name,
                setter.tc().getManagedType().getClassName(),
                oldValue, value);

        describe( "sending notification", notification ) ;

        emitter.sendNotification(notification);
    }

    @TraceRuntime
    public AttributeList getAttributes(FacetAccessor fa, String[] attributes) {
        AttributeList result = new AttributeList();
        for (String str : attributes) {
            Object value = null;

            try {
                value = getAttribute(fa, str);
            } catch (JMException ex) {
                Exceptions.self.attributeGettingError(ex, str);
            }

            // If value == null, we had a problem in trying to fetch it,
            // so just ignore that attribute.  Returning null simply leads to
            // a blank entry in jconsole.  Do not let an error in fetching
            // one attribute prevent fetching the others.

            if (value != null) {
                Attribute attr = new Attribute(str, value);
                result.add(attr);
            }
        }

        return result;
    }

    @TraceRuntime
    public AttributeList setAttributes(
	final NotificationBroadcasterSupport emitter,
	final FacetAccessor fa, final AttributeList attributes) {

	AttributeList result = new AttributeList();

        for (Object elem : attributes) {
            Attribute attr = (Attribute) elem;

            try {
                setAttribute(emitter, fa, attr);
                result.add(attr);
            } catch (JMException ex) {
                Exceptions.self.attributeSettingError(ex, attr.getName());
            }
        }

        return result;
    }

    @TraceRuntime
    public Object invoke(FacetAccessor fa, String actionName, Object params[],
	String sig[]) throws MBeanException, ReflectionException {

	final List<String> signature = Arrays.asList(sig);
	final List<Object> parameters = Arrays.asList(params);

        final Map<List<String>, Operation> opMap = operations.get(
            actionName);
        if (opMap == null) {
            throw Exceptions.self.couldNotFindOperation(actionName);
        }

        final Operation op = opMap.get(signature);
        if (op == null) {
            throw Exceptions.self.couldNotFindOperationAndSignature(
                actionName, signature);
        }

        Object result = op.evaluate(fa, parameters);

	return result;
    }

    @InfoMethod
    private void nameAttributeDescriptorIsNull() {}

    @TraceRuntime
    public String getNameValue(final FacetAccessor fa) throws
	MBeanException, ReflectionException {

	String value = null;
        if (nameAttributeDescriptor == null) {
            nameAttributeDescriptorIsNull() ;
        } else {
            value = nameAttributeDescriptor.get(fa).toString();
        }

	return value;
    }

    public ModelMBeanInfoSupport getMBeanInfo() {
	return mbInfo;
    }

    public ManagedObjectManagerInternal mom() {
	return mom;
    }
}