/*
 * ====================================================================
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.http.cookie;

import java.io.Serializable;
import java.util.Comparator;

import org.apache.http.annotation.Contract;
import org.apache.http.annotation.ThreadingBehavior;

This cookie comparator ensures that multiple cookies satisfying a common criteria are ordered in the Cookie header such that those with more specific Path attributes precede those with less specific. 

This comparator assumes that Path attributes of two cookies
path-match a commmon request-URI. Otherwise, the result of the
comparison is undefined.

Since:
4.0/**
 * This cookie comparator ensures that multiple cookies satisfying
 * a common criteria are ordered in the {@code Cookie} header such
 * that those with more specific Path attributes precede those with
 * less specific.
 *
 * <p>
 * This comparator assumes that Path attributes of two cookies
 * path-match a commmon request-URI. Otherwise, the result of the
 * comparison is undefined.
 * </p>
 *
 *
 * @since 4.0
 */
@Contract(threading = ThreadingBehavior.IMMUTABLE)
public class CookiePathComparator implements Serializable, Comparator<Cookie> {

    public static final CookiePathComparator INSTANCE = new CookiePathComparator();

    private static final long serialVersionUID = 7523645369616405818L;

    private String normalizePath(final Cookie cookie) {
        String path = cookie.getPath();
        if (path == null) {
            path = "/";
        }
        if (!path.endsWith("/")) {
            path = path + '/';
        }
        return path;
    }

    @Override
    public int compare(final Cookie c1, final Cookie c2) {
        final String path1 = normalizePath(c1);
        final String path2 = normalizePath(c2);
        if (path1.equals(path2)) {
            return 0;
        } else if (path1.startsWith(path2)) {
            return -1;
        } else if (path2.startsWith(path1)) {
            return 1;
        } else {
            // Does not really matter
            return 0;
        }
    }

}