/*

 * Copyright 2005-2008 Sun Microsystems, Inc.  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.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package java.net;

import java.util.Map;

import java.util.List;

import java.util.Collections;

import java.util.Comparator;

import java.io.IOException;

/**

 * CookieManager provides a concrete implementation of {@link CookieHandler},

 * which separates the storage of cookies from the policy surrounding accepting

 * and rejecting cookies. A CookieManager is initialized with a {@link CookieStore}

 * which manages storage, and a {@link CookiePolicy} object, which makes

 * policy decisions on cookie acceptance/rejection.

 *

 * <p> The HTTP cookie management in java.net package looks like:

 * <blockquote>

 * <pre>

 *                  use

 * CookieHandler <------- HttpURLConnection

 *       ^

 *       | impl

 *       |         use

 * CookieManager -------> CookiePolicy

 *             |   use

 *             |--------> HttpCookie

 *             |              ^

 *             |              | use

 *             |   use        |

 *             |--------> CookieStore

 *                            ^

 *                            | impl

 *                            |

 *                  Internal in-memory implementation

 * </pre>

 * <ul>

 *   <li>

 *     CookieHandler is at the core of cookie management. User can call

 *     CookieHandler.setDefault to set a concrete CookieHanlder implementation

 *     to be used.

 *   </li>

 *   <li>

 *     CookiePolicy.shouldAccept will be called by CookieManager.put to see whether

 *     or not one cookie should be accepted and put into cookie store. User can use

 *     any of three pre-defined CookiePolicy, namely ACCEPT_ALL, ACCEPT_NONE and

 *     ACCEPT_ORIGINAL_SERVER, or user can define his own CookiePolicy implementation

 *     and tell CookieManager to use it.

 *   </li>

 *   <li>

 *     CookieStore is the place where any accepted HTTP cookie is stored in.

 *     If not specified when created, a CookieManager instance will use an internal

 *     in-memory implementation. Or user can implements one and tell CookieManager

 *     to use it.

 *   </li>

 *   <li>

 *     Currently, only CookieStore.add(URI, HttpCookie) and CookieStore.get(URI)

 *     are used by CookieManager. Others are for completeness and might be needed

 *     by a more sophisticated CookieStore implementation, e.g. a NetscapeCookieSotre.

 *   </li>

 * </ul>

 * </blockquote>

 *

 * <p>There're various ways user can hook up his own HTTP cookie management behavior, e.g.

 * <blockquote>

 * <ul>

 *   <li>Use CookieHandler.setDefault to set a brand new {@link CookieHandler} implementation

 *   <li>Let CookieManager be the default {@link CookieHandler} implementation,

 *       but implement user's own {@link CookieStore} and {@link CookiePolicy}

 *       and tell default CookieManager to use them:

 *     <blockquote><pre>

 *       // this should be done at the beginning of an HTTP session

 *       CookieHandler.setDefault(new CookieManager(new MyCookieStore(), new MyCookiePolicy()));

 *     </pre></blockquote>

 *   <li>Let CookieManager be the default {@link CookieHandler} implementation, but

 *       use customized {@link CookiePolicy}:

 *     <blockquote><pre>

 *       // this should be done at the beginning of an HTTP session

 *       CookieHandler.setDefault(new CookieManager());

 *       // this can be done at any point of an HTTP session

 *       ((CookieManager)CookieHandler.getDefault()).setCookiePolicy(new MyCookiePolicy());

 *     </pre></blockquote>

 * </ul>

 * </blockquote>

 *

 * <p>The implementation conforms to RFC 2965, section 3.3.

 *

 * @author Edward Wang

 * @since 1.6

 */

public class CookieManager extends CookieHandler

{

    /* ---------------- Fields -------------- */

    private CookiePolicy policyCallback;

    private CookieStore cookieJar = null;

    /* ---------------- Ctors -------------- */

    /**

     * Create a new cookie manager.

     *

     * <p>This constructor will create new cookie manager with default

     * cookie store and accept policy. The effect is same as

     * <tt>CookieManager(null, null)</tt>.

     */

    public CookieManager() {

        this(null, null);

    }

    /**

     * Create a new cookie manager with specified cookie store and cookie policy.

     *

     * @param store     a <tt>CookieStore</tt> to be used by cookie manager.

     *                  if <tt>null</tt>, cookie manager will use a default one,

     *                  which is an in-memory CookieStore implmentation.

     * @param cookiePolicy      a <tt>CookiePolicy</tt> instance

     *                          to be used by cookie manager as policy callback.

     *                          if <tt>null</tt>, ACCEPT_ORIGINAL_SERVER will

     *                          be used.

     */

    public CookieManager(CookieStore store,

                         CookiePolicy cookiePolicy)

    {

        // use default cookie policy if not specify one

        policyCallback = (cookiePolicy == null) ? CookiePolicy.ACCEPT_ORIGINAL_SERVER

                                                : cookiePolicy;

        // if not specify CookieStore to use, use default one

        if (store == null) {

            cookieJar = new sun.net.www.protocol.http.InMemoryCookieStore();

        } else {

            cookieJar = store;

        }

    }

    /* ---------------- Public operations -------------- */

    /**

     * To set the cookie policy of this cookie manager.

     *

     * <p> A instance of <tt>CookieManager</tt> will have

     * cookie policy ACCEPT_ORIGINAL_SERVER by default. Users always

     * can call this method to set another cookie policy.

     *

     * @param cookiePolicy      the cookie policy. Can be <tt>null</tt>, which

     *                          has no effects on current cookie policy.

     */

    public void setCookiePolicy(CookiePolicy cookiePolicy) {

        if (cookiePolicy != null) policyCallback = cookiePolicy;

    }

    /**

     * To retrieve current cookie store.

     *

     * @return  the cookie store currently used by cookie manager.

     */

    public CookieStore getCookieStore() {

        return cookieJar;

    }

    public Map<String, List<String>>

        get(URI uri, Map<String, List<String>> requestHeaders)

        throws IOException

    {

        // pre-condition check

        if (uri == null || requestHeaders == null) {

            throw new IllegalArgumentException("Argument is null");

        }

        Map<String, List<String>> cookieMap =

                        new java.util.HashMap<String, List<String>>();

        // if there's no default CookieStore, no way for us to get any cookie

        if (cookieJar == null)

            return Collections.unmodifiableMap(cookieMap);

        boolean secureLink = "https".equalsIgnoreCase(uri.getScheme());

        List<HttpCookie> cookies = new java.util.ArrayList<HttpCookie>();

        String path = uri.getPath();

        if (path == null || path.isEmpty()) {

            path = "/";

        }

        for (HttpCookie cookie : cookieJar.get(uri)) {

            // apply path-matches rule (RFC 2965 sec. 3.3.4)

            // and check for the possible "secure" tag (i.e. don't send

            // 'secure' cookies over unsecure links)

            if (pathMatches(path, cookie.getPath()) &&

                    (secureLink || !cookie.getSecure())) {

                // Let's check the authorize port list if it exists

                String ports = cookie.getPortlist();

                if (ports != null && !ports.isEmpty()) {

                    int port = uri.getPort();

                    if (port == -1) {

                        port = "https".equals(uri.getScheme()) ? 443 : 80;

                    }

                    if (isInPortList(ports, port)) {

                        cookies.add(cookie);

                    }

                } else {

                    cookies.add(cookie);

                }

            }

        }

        // apply sort rule (RFC 2965 sec. 3.3.4)

        List<String> cookieHeader = sortByPath(cookies);

        cookieMap.put("Cookie", cookieHeader);

        return Collections.unmodifiableMap(cookieMap);

    }

    public void

        put(URI uri, Map<String, List<String>> responseHeaders)

        throws IOException

    {

        // pre-condition check

        if (uri == null || responseHeaders == null) {

            throw new IllegalArgumentException("Argument is null");

        }

        // if there's no default CookieStore, no need to remember any cookie

        if (cookieJar == null)

            return;

        for (String headerKey : responseHeaders.keySet()) {

            // RFC 2965 3.2.2, key must be 'Set-Cookie2'

            // we also accept 'Set-Cookie' here for backward compatibility

            if (headerKey == null

                || !(headerKey.equalsIgnoreCase("Set-Cookie2")

                     || headerKey.equalsIgnoreCase("Set-Cookie")

                    )

                )

            {

                continue;

            }

            for (String headerValue : responseHeaders.get(headerKey)) {

                try {

                    List<HttpCookie> cookies = HttpCookie.parse(headerValue);

                    for (HttpCookie cookie : cookies) {

                        if (cookie.getPath() == null) {

                            // If no path is specified, then by default

                            // the path is the directory of the page/doc

                            String path = uri.getPath();

                            if (!path.endsWith("/")) {

                                int i = path.lastIndexOf("/");

                                if (i > 0) {

                                    path = path.substring(0, i + 1);

                                } else {

                                    path = "/";

                                }

                            }

                            cookie.setPath(path);

                        }

                        String ports = cookie.getPortlist();

                        if (ports != null) {

                            int port = uri.getPort();

                            if (port == -1) {

                                port = "https".equals(uri.getScheme()) ? 443 : 80;

                            }

                            if (ports.isEmpty()) {

                                // Empty port list means this should be restricted

                                // to the incoming URI port

                                cookie.setPortlist("" + port );

                                if (shouldAcceptInternal(uri, cookie)) {

                                    cookieJar.add(uri, cookie);

                                }

                            } else {

                                // Only store cookies with a port list

                                // IF the URI port is in that list, as per

                                // RFC 2965 section 3.3.2

                                if (isInPortList(ports, port) &&

                                        shouldAcceptInternal(uri, cookie)) {

                                    cookieJar.add(uri, cookie);

                                }

                            }

                        } else {

                            if (shouldAcceptInternal(uri, cookie)) {

                                cookieJar.add(uri, cookie);

                            }

                        }

                    }

                } catch (IllegalArgumentException e) {

                    // invalid set-cookie header string

                    // no-op

                }

            }

        }

    }

    /* ---------------- Private operations -------------- */

    // to determine whether or not accept this cookie

    private boolean shouldAcceptInternal(URI uri, HttpCookie cookie) {

        try {

            return policyCallback.shouldAccept(uri, cookie);

        } catch (Exception ignored) { // pretect against malicious callback

            return false;

        }

    }

    static private boolean isInPortList(String lst, int port) {

        int i = lst.indexOf(",");

        int val = -1;

        while (i > 0) {

            try {

                val = Integer.parseInt(lst.substring(0, i));

                if (val == port) {

                    return true;

                }

            } catch (NumberFormatException numberFormatException) {

            }

            lst = lst.substring(i+1);

            i = lst.indexOf(",");

        }

        if (!lst.isEmpty()) {

            try {

                val = Integer.parseInt(lst);

                if (val == port) {

                    return true;

                }

            } catch (NumberFormatException numberFormatException) {

            }

        }

        return false;

    }

    /*

     * path-matches algorithm, as defined by RFC 2965

     */

    private boolean pathMatches(String path, String pathToMatchWith) {

        if (path == pathToMatchWith)

            return true;

        if (path == null || pathToMatchWith == null)

            return false;

        if (path.startsWith(pathToMatchWith))

            return true;

        return false;

    }

    /*

     * sort cookies with respect to their path: those with more specific Path attributes

     * precede those with less specific, as defined in RFC 2965 sec. 3.3.4

     */

    private List<String> sortByPath(List<HttpCookie> cookies) {

        Collections.sort(cookies, new CookiePathComparator());

        List<String> cookieHeader = new java.util.ArrayList<String>();

        for (HttpCookie cookie : cookies) {

            // Netscape cookie spec and RFC 2965 have different format of Cookie

            // header; RFC 2965 requires a leading $Version="1" string while Netscape

            // does not.

            // The workaround here is to add a $Version="1" string in advance

            if (cookies.indexOf(cookie) == 0 && cookie.getVersion() > 0) {

                cookieHeader.add("$Version=\"1\"");

            }

            cookieHeader.add(cookie.toString());

        }

        return cookieHeader;

    }

    static class CookiePathComparator implements Comparator<HttpCookie> {

        public int compare(HttpCookie c1, HttpCookie c2) {

            if (c1 == c2) return 0;

            if (c1 == null) return -1;

            if (c2 == null) return 1;

            // path rule only applies to the cookies with same name

            if (!c1.getName().equals(c2.getName())) return 0;

            // those with more specific Path attributes precede those with less specific

            if (c1.getPath().startsWith(c2.getPath()))

                return -1;

            else if (c2.getPath().startsWith(c1.getPath()))

                return 1;

            else

                return 0;

        }

    }

}