/*
 * Copyright (c) 2002, 2017, 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.
 */

import java.util.EnumSet;
import java.util.List;
import java.util.Set;
import javax.lang.model.element.Element;

import com.sun.source.doctree.DocTree;
import com.sun.source.doctree.TextTree;
import com.sun.source.doctree.UnknownBlockTagTree;
import com.sun.source.doctree.UnknownInlineTagTree;
import com.sun.source.util.SimpleDocTreeVisitor;
import jdk.javadoc.doclet.Taglet;

/**
 * A sample Inline Taglet representing {@underline ...}. This tag can
 * be used in any kind of {@link javax.lang.model.Element}.
 * The text is underlined.  For example,
 * "@underline UNDERLINE ME" would be shown as: <u>UNDERLINE ME</u>.
 *
 * @author Jamie Ho
 * @since 1.4
 */

public class UnderlineTaglet implements Taglet {

    private static final String NAME = "underline";

    /**
     * Return the name of this custom tag.
     */
    public String getName() {
        return NAME;
    }

    private final EnumSet<Location> allowedSet = EnumSet.allOf(Location.class);

    @Override
    public Set<Taglet.Location> getAllowedLocations() {
        return allowedSet;
    }

    /**
     * Will return true since this is an inline tag.
     * @return true since this is an inline tag.
     */

    public boolean isInlineTag() {
        return true;
    }

    /**
     * Given the <code>DocTree</code> representation of this custom
     * tag, return its string representation.
     * @param tags the list of trees representing of this custom tag.
     * @param element the declaration to which the enclosing comment belongs
     */
    public String toString(List<? extends DocTree> tags, Element element) {
        return "<u>" + getText(tags.get(0)) + "</u>";
    }

    static String getText(DocTree dt) {
        return new SimpleDocTreeVisitor<String, Void>() {
            @Override
            public String visitUnknownBlockTag(UnknownBlockTagTree node, Void p) {
                for (DocTree dt : node.getContent()) {
                    return dt.accept(this, null);
                }
                return "";
            }

            @Override
            public String visitUnknownInlineTag(UnknownInlineTagTree node, Void p) {
                for (DocTree dt : node.getContent()) {
                    return dt.accept(this, null);
                }
                return "";
            }

            @Override
            public String visitText(TextTree node, Void p) {
                return node.getBody();
            }

            @Override
            protected String defaultAction(DocTree node, Void p) {
                return "";
            }

        }.visit(dt, null);
    }
}