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 * Copyright (c) 2019, 2020, 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
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package jdk.javadoc.internal.doclets.formats.html;

import com.sun.source.doctree.DocTree;
import jdk.javadoc.internal.doclets.formats.html.markup.BodyContents;
import jdk.javadoc.internal.doclets.formats.html.markup.ContentBuilder;
import jdk.javadoc.internal.doclets.formats.html.markup.FixedStringContent;
import jdk.javadoc.internal.doclets.formats.html.markup.HtmlStyle;
import jdk.javadoc.internal.doclets.formats.html.markup.HtmlTree;
import jdk.javadoc.internal.doclets.formats.html.Navigation.PageMode;
import jdk.javadoc.internal.doclets.formats.html.markup.StringContent;
import jdk.javadoc.internal.doclets.formats.html.markup.Table;
import jdk.javadoc.internal.doclets.formats.html.markup.TableHeader;
import jdk.javadoc.internal.doclets.toolkit.Content;
import jdk.javadoc.internal.doclets.toolkit.DocletElement;
import jdk.javadoc.internal.doclets.toolkit.OverviewElement;
import jdk.javadoc.internal.doclets.toolkit.util.DocFileIOException;
import jdk.javadoc.internal.doclets.toolkit.util.DocPath;
import jdk.javadoc.internal.doclets.toolkit.util.DocPaths;
import jdk.javadoc.internal.doclets.toolkit.util.IndexItem;

import javax.lang.model.element.Element;
import java.nio.file.Path;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.TreeMap;
import java.util.WeakHashMap;

import static java.util.stream.Collectors.groupingBy;
import static java.util.stream.Collectors.toList;

Generates the file with the summary of all the system properties.
 
This is NOT part of any supported API.
 If you write code that depends on this, you do so at your own risk.
 This code and its internal interfaces are subject to change or
 deletion without notice.
/**
 * Generates the file with the summary of all the system properties.
 *
 *  <p><b>This is NOT part of any supported API.
 *  If you write code that depends on this, you do so at your own risk.
 *  This code and its internal interfaces are subject to change or
 *  deletion without notice.</b>
 */
public class SystemPropertiesWriter extends HtmlDocletWriter {

    
Cached contents of <title>...</title> tags of the HTML pages. /**
     * Cached contents of {@code <title>...</title>} tags of the HTML pages.
     */
    final Map<Element, String> titles = new WeakHashMap<>();

    
Constructs SystemPropertiesWriter object.
Params:
configuration – The current configuration
filename – Path to the file which is getting generated./**
     * Constructs SystemPropertiesWriter object.
     *
     * @param configuration The current configuration
     * @param filename Path to the file which is getting generated.
     */
    public SystemPropertiesWriter(HtmlConfiguration configuration, DocPath filename) {
        super(configuration, filename);
    }

    public static void generate(HtmlConfiguration configuration) throws DocFileIOException {
        generate(configuration, DocPaths.SYSTEM_PROPERTIES);
    }

    private static void generate(HtmlConfiguration configuration, DocPath fileName) throws DocFileIOException {
        boolean hasSystemProperties = configuration.mainIndex != null
                && !configuration.mainIndex.getItems(DocTree.Kind.SYSTEM_PROPERTY).isEmpty();
        if (!hasSystemProperties) {
            // Cannot defer this check any further, because of the super() call
            // that prints out notices on creating files, etc.
            //
            // There is probably a better place for this kind of checks (see how
            // this is achieved in other "optional" pages, like Constant Values
            // and Serialized Form).
            return;
        }
        SystemPropertiesWriter systemPropertiesGen = new SystemPropertiesWriter(configuration, fileName);
        systemPropertiesGen.buildSystemPropertiesPage();
        configuration.conditionalPages.add(HtmlConfiguration.ConditionalPage.SYSTEM_PROPERTIES);
    }

    
Prints all the system properties to the file.
/**
     * Prints all the system properties to the file.
     */
    protected void buildSystemPropertiesPage() throws DocFileIOException {
        String title = resources.getText("doclet.systemProperties");
        HtmlTree body = getBody(getWindowTitle(title));
        Content mainContent = new ContentBuilder();
        addSystemProperties(mainContent);
        body.add(new BodyContents()
                .setHeader(getHeader(PageMode.SYSTEM_PROPERTIES))
                .addMainContent(HtmlTree.DIV(HtmlStyle.header,
                        HtmlTree.HEADING(Headings.PAGE_TITLE_HEADING,
                                contents.getContent("doclet.systemProperties"))))
                .addMainContent(mainContent)
                .setFooter(getFooter()));
        printHtmlDocument(null, "system properties", body);

        if (configuration.mainIndex != null) {
            configuration.mainIndex.add(IndexItem.of(IndexItem.Category.TAGS, title, path));
        }
    }

    
Adds all the system properties to the content tree.
Params:
content – HtmlTree content to which the links will be added/**
     * Adds all the system properties to the content tree.
     *
     * @param content HtmlTree content to which the links will be added
     */
    protected void addSystemProperties(Content content) {
        Map<String, List<IndexItem>> searchIndexMap = groupSystemProperties();
        Content separator = new StringContent(", ");
        Table table = new Table(HtmlStyle.summaryTable)
                .setCaption(contents.systemPropertiesSummaryLabel)
                .setHeader(new TableHeader(contents.propertyLabel, contents.referencedIn))
                .setColumnStyles(HtmlStyle.colFirst, HtmlStyle.colLast);
        for (Entry<String, List<IndexItem>> entry : searchIndexMap.entrySet()) {
            Content propertyName = new StringContent(entry.getKey());
            List<IndexItem> searchIndexItems = entry.getValue();
            Content separatedReferenceLinks = new ContentBuilder();
            separatedReferenceLinks.add(createLink(searchIndexItems.get(0)));
            for (int i = 1; i < searchIndexItems.size(); i++) {
                separatedReferenceLinks.add(separator);
                separatedReferenceLinks.add(createLink(searchIndexItems.get(i)));
            }
            table.addRow(propertyName, HtmlTree.DIV(HtmlStyle.block, separatedReferenceLinks));
        }
        content.add(table);
    }

    private Map<String, List<IndexItem>> groupSystemProperties() {
        return configuration.mainIndex.getItems(DocTree.Kind.SYSTEM_PROPERTY).stream()
                .collect(groupingBy(IndexItem::getLabel, TreeMap::new, toList()));
    }

    private Content createLink(IndexItem i) {
        assert i.getDocTree().getKind() == DocTree.Kind.SYSTEM_PROPERTY : i;
        Element element = i.getElement();
        if (element instanceof OverviewElement) {
            return links.createLink(pathToRoot.resolve(i.getUrl()),
                    resources.getText("doclet.Overview"));
        } else if (element instanceof DocletElement) {
            DocletElement e = (DocletElement) element;
            // Implementations of DocletElement do not override equals and
            // hashCode; putting instances of DocletElement in a map is not
            // incorrect, but might well be inefficient
            String t = titles.computeIfAbsent(element, utils::getHTMLTitle);
            if (t.isBlank()) {
                // The user should probably be notified (a warning?) that this
                // file does not have a title
                Path p = Path.of(e.getFileObject().toUri());
                t = p.getFileName().toString();
            }
            ContentBuilder b = new ContentBuilder();
            b.add(HtmlTree.CODE(new FixedStringContent(i.getHolder() + ": ")));
            // non-program elements should be displayed using a normal font
            b.add(t);
            return links.createLink(pathToRoot.resolve(i.getUrl()), b);
        } else {
            // program elements should be displayed using a code font
            Content link = links.createLink(pathToRoot.resolve(i.getUrl()), i.getHolder());
            return HtmlTree.CODE(link);
        }
    }
}