/*

 * Copyright (c) 2018, 2018, 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.

 *

 * 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 org.graalvm.compiler.hotspot.management;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Comparator;

import java.util.List;

import javax.management.Attribute;

import javax.management.AttributeList;

import javax.management.AttributeNotFoundException;

import javax.management.DynamicMBean;

import javax.management.InvalidAttributeValueException;

import javax.management.MBeanAttributeInfo;

import javax.management.MBeanException;

import javax.management.MBeanInfo;

import javax.management.MBeanOperationInfo;

import javax.management.MBeanParameterInfo;

import javax.management.ObjectName;

import javax.management.ReflectionException;

import jdk.internal.vm.compiler.collections.EconomicMap;

import org.graalvm.compiler.core.common.SuppressFBWarnings;

import org.graalvm.compiler.debug.TTY;

import org.graalvm.compiler.hotspot.HotSpotGraalRuntime;

import org.graalvm.compiler.options.OptionDescriptor;

import org.graalvm.compiler.options.OptionDescriptors;

import org.graalvm.compiler.options.OptionsParser;

/**

 * MBean used to access properties and operations of a {@link HotSpotGraalRuntime} instance.

 */

final class HotSpotGraalRuntimeMBean implements DynamicMBean {

    /**

     * The runtime instance to which this bean provides a management connection.

     */

    private final HotSpotGraalRuntime runtime;

    /**

     * The object name under which the bean is registered.

     */

    private final ObjectName objectName;

    HotSpotGraalRuntimeMBean(ObjectName objectName, HotSpotGraalRuntime runtime) {

        this.objectName = objectName;

        this.runtime = runtime;

    }

    ObjectName getObjectName() {

        return objectName;

    }

    HotSpotGraalRuntime getRuntime() {

        return runtime;

    }

    private static final boolean DEBUG = Boolean.getBoolean(HotSpotGraalRuntimeMBean.class.getSimpleName() + ".debug");

    @Override

    public Object getAttribute(String name) throws AttributeNotFoundException {

        String[] result = runtime.getOptionValues(name);

        String value = result[0];

        if (value == null) {

            throw new AttributeNotFoundException(name);

        }

        if (DEBUG) {

            System.out.printf("getAttribute: %s = %s (type: %s)%n", name, value, value == null ? "null" : value.getClass().getName());

        }

        return result[0];

    }

    @SuppressFBWarnings(value = "ES_COMPARING_STRINGS_WITH_EQ", justification = "reference equality on the receiver is what we want")

    @Override

    public void setAttribute(Attribute attribute) throws AttributeNotFoundException, InvalidAttributeValueException {

        String name = attribute.getName();

        Object value = attribute.getValue();

        String svalue = String.valueOf(value);

        if (DEBUG) {

            System.out.printf("setAttribute: %s = %s (type: %s)%n", name, svalue, value == null ? "null" : value.getClass().getName());

        }

        String[] result = runtime.setOptionValues(new String[]{name}, new String[]{svalue});

        if (result[0] != name) {

            if (result[0] == null) {

                throw new AttributeNotFoundException(name);

            }

            throw new InvalidAttributeValueException(result[0]);

        }

    }

    @Override

    public AttributeList getAttributes(String[] names) {

        String[] values = runtime.getOptionValues(names);

        AttributeList list = new AttributeList();

        for (int i = 0; i < names.length; i++) {

            String value = values[i];

            String name = names[i];

            if (value == null) {

                TTY.printf("No such option named %s%n", name);

            } else {

                if (DEBUG) {

                    System.out.printf("getAttributes: %s = %s (type: %s)%n", name, value, value == null ? "null" : value.getClass().getName());

                }

                list.add(new Attribute(name, value));

            }

        }

        return list;

    }

    @SuppressFBWarnings(value = "ES_COMPARING_STRINGS_WITH_EQ", justification = "reference equality on the receiver is what we want")

    @Override

    public AttributeList setAttributes(AttributeList attributes) {

        String[] names = new String[attributes.size()];

        String[] values = new String[attributes.size()];

        int i = 0;

        for (Attribute attr : attributes.asList()) {

            String name = attr.getName();

            names[i] = name;

            Object value = attr.getValue();

            String svalue = String.valueOf(value);

            values[i] = svalue;

            if (DEBUG) {

                System.out.printf("setAttributes: %s = %s (type: %s)%n", name, svalue, value == null ? "null" : value.getClass().getName());

            }

            i++;

        }

        String[] result = runtime.setOptionValues(names, values);

        AttributeList setOk = new AttributeList();

        i = 0;

        for (Attribute attr : attributes.asList()) {

            if (names[i] == result[i]) {

                setOk.add(attr);

            } else if (result[i] == null) {

                TTY.printf("Error setting %s to %s: unknown option%n", attr.getName(), attr.getValue());

            } else {

                TTY.printf("Error setting %s to %s: %s%n", attr.getName(), attr.getValue(), result[i]);

            }

            i++;

        }

        return setOk;

    }

    @Override

    public Object invoke(String actionName, Object[] params, String[] signature) throws MBeanException, ReflectionException {

        try {

            if (DEBUG) {

                System.out.printf("invoke: %s%s%n", actionName, Arrays.asList(params));

            }

            if (DEBUG) {

                System.out.printf("invoke: %s%s = %s%n", actionName, Arrays.asList(params), retvalue);

            }

            return retvalue;

        } catch (Exception ex) {

            throw new ReflectionException(ex);

        }

    }

    @Override

    public MBeanInfo getMBeanInfo() {

        List<MBeanAttributeInfo> attrs = new ArrayList<>();

        for (OptionDescriptor option : getOptionDescriptors().getValues()) {

            Class<?> optionValueType = option.getOptionValueType();

            if (Enum.class.isAssignableFrom(optionValueType)) {

                // Enum values are passed through

                // the management interface as Strings.

                optionValueType = String.class;

            }

            attrs.add(new MBeanAttributeInfo(option.getName(), optionValueType.getName(), option.getHelp(), true, true, false));

        }

        attrs.sort(new Comparator<MBeanAttributeInfo>() {

            @Override

            public int compare(MBeanAttributeInfo o1, MBeanAttributeInfo o2) {

                return o1.getName().compareTo(o2.getName());

            }

        });

        return new MBeanInfo(

                        HotSpotGraalRuntimeMBean.class.getName(),

                        "Graal",

                        attrs.toArray(new MBeanAttributeInfo[attrs.size()]),

    }

    private static EconomicMap<String, OptionDescriptor> getOptionDescriptors() {

        EconomicMap<String, OptionDescriptor> result = EconomicMap.create();

        for (OptionDescriptors set : OptionsParser.getOptionsLoader()) {

            for (OptionDescriptor option : set) {

                result.put(option.getName(), option);

            }

        }

        return result;

    }

}