/*

 * Copyright (c) 2012, 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 com.sun.tools.doclets.internal.toolkit.util;

/**

 * Abstraction for simple relative URIs, consisting of a path,

 * an optional query, and an optional fragment. DocLink objects can

 * be created by the constructors below or from a DocPath using the

 * convenience methods, {@link DocPath#fragment fragment} and

 * {@link DocPath#query query}.

 *

 *  <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 DocLink {

    final String path;

    final String query;

    final String fragment;

    /** Create a DocLink representing the URI {@code #fragment}. */

    public static DocLink fragment(String fragment) {

        return new DocLink((String) null, (String) null, fragment);

    }

    /** Create a DocLink representing the URI {@code path}. */

    public DocLink(DocPath path) {

        this(path.getPath(), null, null);

    }

    /**

     * Create a DocLink representing the URI {@code path?query#fragment}.

     * query and fragment may be null.

     */

    public DocLink(DocPath path, String query, String fragment) {

        this(path.getPath(), query, fragment);

    }

    /**

     * Create a DocLink representing the URI {@code path?query#fragment}.

     * Any of the component parts may be null.

     */

    public DocLink(String path, String query, String fragment) {

        this.path = path;

        this.query = query;

        this.fragment = fragment;

    }

    /**

     * Return the link in the form "path?query#fragment", omitting any empty

     * components.

     */

    @Override

    public String toString() {

        // common fast path

        if (path != null && isEmpty(query) && isEmpty(fragment))

            return path;

        StringBuilder sb = new StringBuilder();

        if (path != null)

            sb.append(path);

        if (!isEmpty(query))

            sb.append("?").append(query);

        if (!isEmpty(fragment))

            sb.append("#").append(fragment);

        return sb.toString();

    }

    private static boolean isEmpty(String s) {

        return (s == null) || s.isEmpty();

    }

}