/*

 * Copyright (c) 2016, 2019, 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.javadoc.internal.doclets.formats.html;

import java.util.Collections;

import jdk.javadoc.internal.doclets.formats.html.markup.Head;

import jdk.javadoc.internal.doclets.formats.html.markup.ContentBuilder;

import jdk.javadoc.internal.doclets.formats.html.markup.DocType;

import jdk.javadoc.internal.doclets.formats.html.markup.HtmlAttr;

import jdk.javadoc.internal.doclets.formats.html.markup.HtmlDocument;

import jdk.javadoc.internal.doclets.formats.html.markup.HtmlTag;

import jdk.javadoc.internal.doclets.formats.html.markup.HtmlTree;

import jdk.javadoc.internal.doclets.formats.html.markup.Script;

import jdk.javadoc.internal.doclets.formats.html.markup.StringContent;

import jdk.javadoc.internal.doclets.toolkit.Content;

import jdk.javadoc.internal.doclets.toolkit.util.DocFile;

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 java.util.Collections;

/**

 * Writes a file that tries to redirect to an alternate page.

 * The redirect uses JavaScript, if enabled, falling back on

 * {@code <meta http-eqiv=refresh content="0,<uri>">}.

 * If neither are supported/enabled in a browser, the page displays the

 * standard "JavaScipt not enabled" message, and a link to the alternate page.

 */

public class IndexRedirectWriter extends HtmlDocletWriter {

    public static void generate(HtmlConfiguration configuration)

            throws DocFileIOException {

        generate(configuration, DocPaths.INDEX, configuration.topFile);

    }

    public static void generate(HtmlConfiguration configuration, DocPath fileName, DocPath target)

            throws DocFileIOException {

        IndexRedirectWriter indexRedirect = new IndexRedirectWriter(configuration, fileName, target);

        indexRedirect.generateIndexFile();

    }

    private DocPath target;

    private IndexRedirectWriter(HtmlConfiguration configuration, DocPath filename, DocPath target) {

        super(configuration, filename);

        this.target = target;

    }

    /**

     * Generate an index file that redirects to an alternate file.

     * @throws DocFileIOException if there is a problem generating the file

     */

    private void generateIndexFile() throws DocFileIOException {

        Content htmlComment = contents.newPage;

        Head head = new Head(path, configuration.docletVersion)

                .setTimestamp(true)

                .setDescription("index redirect")

                .setGenerator(getGenerator(getClass()))

                .setStylesheets(configuration.getMainStylesheet(), Collections.emptyList()) // avoid reference to default stylesheet

                .addDefaultScript(false);

        String title = (configuration.windowtitle.length() > 0)

                ? configuration.windowtitle

                : resources.getText("doclet.Generated_Docs_Untitled");

        head.setTitle(title)

                .setCharset(configuration.charset)

                .setCanonicalLink(target);

        String targetPath = target.getPath();

        Script script = new Script("window.location.replace(")

                .appendStringLiteral(targetPath, '\'')

                .append(")");

        HtmlTree metaRefresh = new HtmlTree(HtmlTag.META)

                .addAttr(HtmlAttr.HTTP_EQUIV, "Refresh")

                .addAttr(HtmlAttr.CONTENT, "0;" + targetPath);

        head.addContent(script.asContent(), HtmlTree.NOSCRIPT(metaRefresh));

        ContentBuilder bodyContent = new ContentBuilder();

        bodyContent.addContent(HtmlTree.NOSCRIPT(

                HtmlTree.P(contents.getContent("doclet.No_Script_Message"))));

        bodyContent.addContent(HtmlTree.P(HtmlTree.A(targetPath, new StringContent(targetPath))));

        HtmlTree main = HtmlTree.MAIN(bodyContent);

        body.addContent(main);

        Content htmlTree = HtmlTree.HTML(configuration.getLocale().getLanguage(), head.toContent(), body);

        HtmlDocument htmlDocument = new HtmlDocument(htmlComment, htmlTree);

        htmlDocument.write(DocFile.createFileForOutput(configuration, path));

    }

}