/*

 * Copyright (c) 2016, 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.  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 jdk.management.jfr;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

import java.util.StringJoiner;

import javax.management.openmbean.CompositeData;

import jdk.jfr.Category;

import jdk.jfr.EventType;

import jdk.jfr.SettingDescriptor;

/**

 * Management representation of an {@code EventType}.

 *

 * @see EventType

 *

 * @since 9

 */

public final class EventTypeInfo {

    private final List<SettingDescriptorInfo> settings;

    private final long id;

    private final String name;

    private final String description;

    private final String label;

    private final List<String> categoryNames;

    // package private

    EventTypeInfo(EventType eventType) {

        this.settings = creatingSettingDescriptorInfos(eventType);

        this.id = eventType.getId();

        this.name = eventType.getName();

        this.label = eventType.getLabel();

        this.description = eventType.getDescription();

        this.categoryNames = eventType.getCategoryNames();

    }

    private EventTypeInfo(CompositeData cd) {

        this.settings = createSettings(cd.get("settings"));

        this.id = (long) cd.get("id");

        this.name = (String) cd.get("name");

        this.label = (String) cd.get("label");

        this.description = (String) cd.get("description");

        this.categoryNames = createCategoryNames((Object[]) cd.get("category"));

    }

    private static List<String> createCategoryNames(Object[] array) {

        List<String> list = new ArrayList<>(array.length);

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

            list.add((String) array[i]);

        }

        return Collections.unmodifiableList(list);

    }

    private static List<SettingDescriptorInfo> creatingSettingDescriptorInfos(EventType eventType) {

        List<SettingDescriptor> settings = eventType.getSettingDescriptors();

        List<SettingDescriptorInfo> settingDescriptorInfos = new ArrayList<>(settings.size());

        for (SettingDescriptor s : settings) {

            settingDescriptorInfos.add(new SettingDescriptorInfo(s));

        }

        return Collections.unmodifiableList(settingDescriptorInfos);

    }

    private static List<SettingDescriptorInfo> createSettings(Object settings) {

        if (settings != null && settings.getClass().isArray()) {

            Object[] settingsArray = (Object[]) settings;

            List<SettingDescriptorInfo> list = new ArrayList<>(settingsArray.length);

            for (Object cd : settingsArray) {

                if (cd instanceof CompositeData) {

                    list.add(SettingDescriptorInfo.from((CompositeData) cd));

                }

            }

            return Collections.unmodifiableList(list);

        }

        return Collections.emptyList();

    }

    /**

     * Returns the label, a human-readable name, associated with the event type

     * for this {@code EventTypeInfo} (for example, {@code "Garbage Collection"}).

     *

     * @return the label, or {@code null} if a label is not set

     *

     * @see EventType#getLabel()

     */

    public String getLabel() {

        return label;

    }

    /**

     *

     * Returns the list of human-readable names that makes up the category for this

     * {@code EventTypeInfo} (for example, {@code "Java Virtual Machine"} or {@code "Garbage Collector"}).

     *

     * @return an immutable list of category names, or a list with the name

     *         {@code "Uncategorized"} if no category has been set

     *

     * @see EventType#getCategoryNames()

     * @see Category

     */

    public List<String> getCategoryNames() {

        return categoryNames;

    }

    /**

     * Returns the unique ID for the event type associated with this

     * {@code EventTypeInfo}, not guaranteed to be the same for different Java

     * Virtual Machines (JVMs) instances.

     *

     * @return the ID

     *

     * @see EventType#getId()

     */

    public long getId() {

        return id;

    }

    /**

     * Returns the name for the event type associated with this

     * {@code EventTypeInfo} (for example, {@code "jdk.GarbageCollection"}).

     *

     * @return the name, not {@code null}

     *

     * @see EventType#getName()

     */

    public String getName() {

        return name;

    }

    /**

     * Returns a short sentence or two describing the event type associated with

     * this {@code EventTypeInfo}, for example

     * {@code "Garbage collection performed by the JVM""}.

     *

     * @return the description, or {@code null} if no description exists

     *

     * @see EventType#getDescription()

     */

    public String getDescription() {

        return description;

    }

    /**

     * Returns settings for the event type associated with this

     * {@code EventTypeInfo}.

     *

     * @return the settings, not {@code null}

     *

     * @see EventType#getSettingDescriptors()

     */

    public List<SettingDescriptorInfo> getSettingDescriptors() {

        return settings;

    }

    /**

     * Returns a description of this {@code EventTypeInfo}.

     *

     * @return description, not {@code null}

     */

    @Override

    public String toString() {

        Stringifier s = new Stringifier();

        s.add("id", id);

        s.add("name", name);

        s.add("label", label);

        s.add("description", description);

        StringJoiner sj = new StringJoiner(", ", "{", "}");

        for (String categoryName : categoryNames) {

            sj.add(categoryName);

        }

        s.add("category", sj.toString());

        return s.toString();

    }

    /**

     * Returns an {@code EventType} represented by the specified

     * {@code CompositeData}

     * <p>

     * The supplied {@code CompositeData} must have the following item names and

     * item types to be valid. <blockquote>

     * <table class="striped">

     * <caption>The name and type the specified CompositeData must contain</caption>

     * <thead>

     * <tr>

     * <th scope="col" style="text-align:left">Name</th>

     * <th scope="col" style="text-align:left">Type</th>

     * </tr>

     * </thead>

     * <tbody>

     * <tr>

     * <th scope="row">id</th>

     * <td>{@code Long}</td>

     * </tr>

     * <tr>

     * <th scope="row">name</th>

     * <td>{@code String}</td>

     * </tr>

     * <tr>

     * <th scope="row">label</th>

     * <td>{@code String}</td>

     * </tr>

     * <tr>

     * <th scope="row">description</th>

     * <td>{@code String}</td>

     * </tr>

     * <tr>

     * <th scope="row">category</th>

     * <td><code>ArrayType(1, SimpleType.STRING)</code></td>

     * </tr>

     * <tr>

     * <th scope="row">settings</th>

     * <td>{@code javax.management.openmbean.CompositeData[]} whose element type

     * is the mapped type for {@link SettingDescriptorInfo} as specified in the

     * {@link SettingDescriptorInfo#from} method.</td>

     *

     * </tr>

     * </tbody>

     * </table>

     * </blockquote>

     *

     * @param cd {@code CompositeData} representing the {@code EventTypeInfo} to

     *        return

     *

     * @throws IllegalArgumentException if {@code cd} does not represent a valid

     *         {@code EventTypeInfo}

     *

     * @return an {@code EventTypeInfo}, or {@code null} if {@code cd} is

     *         {@code null}

     */

    public static EventTypeInfo from(CompositeData cd) {

        if (cd == null) {

            return null;

        }

        return new EventTypeInfo(cd);

    }

}