/*

 * Copyright (c) 2005, 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 java.net;

import java.net.URI;

import java.net.CookieStore;

import java.net.HttpCookie;

import java.net.URISyntaxException;

import java.util.List;

import java.util.Map;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.Collections;

import java.util.Iterator;

import java.util.concurrent.locks.ReentrantLock;

/**

 * A simple in-memory java.net.CookieStore implementation

 *

 * @author Edward Wang

 * @since 1.6

 */

class InMemoryCookieStore implements CookieStore {

    // the in-memory representation of cookies

    private List<HttpCookie> cookieJar = null;

    // the cookies are indexed by its domain and associated uri (if present)

    // CAUTION: when a cookie removed from main data structure (i.e. cookieJar),

    //          it won't be cleared in domainIndex & uriIndex. Double-check the

    //          presence of cookie when retrieve one form index store.

    private Map<String, List<HttpCookie>> domainIndex = null;

    private Map<URI, List<HttpCookie>> uriIndex = null;

    // use ReentrantLock instead of synchronized for scalability

    private ReentrantLock lock = null;

    /**

     * The default ctor

     */

    public InMemoryCookieStore() {

        cookieJar = new ArrayList<>();

        domainIndex = new HashMap<>();

        uriIndex = new HashMap<>();

        lock = new ReentrantLock(false);

    }

    /**

     * Add one cookie into cookie store.

     */

    public void add(URI uri, HttpCookie cookie) {

        // pre-condition : argument can't be null

        if (cookie == null) {

            throw new NullPointerException("cookie is null");

        }

        lock.lock();

        try {

            // remove the ole cookie if there has had one

            cookieJar.remove(cookie);

            // add new cookie if it has a non-zero max-age

            if (cookie.getMaxAge() != 0) {

                cookieJar.add(cookie);

                // and add it to domain index

                if (cookie.getDomain() != null) {

                    addIndex(domainIndex, cookie.getDomain(), cookie);

                }

                if (uri != null) {

                    // add it to uri index, too

                    addIndex(uriIndex, getEffectiveURI(uri), cookie);

                }

            }

        } finally {

            lock.unlock();

        }

    }

    /**

     * Get all cookies, which:

     *  1) given uri domain-matches with, or, associated with

     *     given uri when added to the cookie store.

     *  3) not expired.

     * See RFC 2965 sec. 3.3.4 for more detail.

     */

    public List<HttpCookie> get(URI uri) {

        // argument can't be null

        if (uri == null) {

            throw new NullPointerException("uri is null");

        }

        List<HttpCookie> cookies = new ArrayList<>();

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

        lock.lock();

        try {

            // check domainIndex first

            getInternal1(cookies, domainIndex, uri.getHost(), secureLink);

            // check uriIndex then

            getInternal2(cookies, uriIndex, getEffectiveURI(uri), secureLink);

        } finally {

            lock.unlock();

        }

        return cookies;

    }

    /**

     * Get all cookies in cookie store, except those have expired

     */

    public List<HttpCookie> getCookies() {

        List<HttpCookie> rt;

        lock.lock();

        try {

            Iterator<HttpCookie> it = cookieJar.iterator();

            while (it.hasNext()) {

                if (it.next().hasExpired()) {

                    it.remove();

                }

            }

        } finally {

            rt = Collections.unmodifiableList(cookieJar);

            lock.unlock();

        }

        return rt;

    }

    /**

     * Get all URIs, which are associated with at least one cookie

     * of this cookie store.

     */

    public List<URI> getURIs() {

        List<URI> uris = new ArrayList<>();

        lock.lock();

        try {

            Iterator<URI> it = uriIndex.keySet().iterator();

            while (it.hasNext()) {

                URI uri = it.next();

                List<HttpCookie> cookies = uriIndex.get(uri);

                if (cookies == null || cookies.size() == 0) {

                    // no cookies list or an empty list associated with

                    // this uri entry, delete it

                    it.remove();

                }

            }

        } finally {

            uris.addAll(uriIndex.keySet());

            lock.unlock();

        }

        return uris;

    }

    /**

     * Remove a cookie from store

     */

    public boolean remove(URI uri, HttpCookie ck) {

        // argument can't be null

        if (ck == null) {

            throw new NullPointerException("cookie is null");

        }

        boolean modified = false;

        lock.lock();

        try {

            modified = cookieJar.remove(ck);

        } finally {

            lock.unlock();

        }

        return modified;

    }

    /**

     * Remove all cookies in this cookie store.

     */

    public boolean removeAll() {

        lock.lock();

        try {

            if (cookieJar.isEmpty()) {

                return false;

            }

            cookieJar.clear();

            domainIndex.clear();

            uriIndex.clear();

        } finally {

            lock.unlock();

        }

        return true;

    }

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

    /*

     * This is almost the same as HttpCookie.domainMatches except for

     * one difference: It won't reject cookies when the 'H' part of the

     * domain contains a dot ('.').

     * I.E.: RFC 2965 section 3.3.2 says that if host is x.y.domain.com

     * and the cookie domain is .domain.com, then it should be rejected.

     * However that's not how the real world works. Browsers don't reject and

     * some sites, like yahoo.com do actually expect these cookies to be

     * passed along.

     * And should be used for 'old' style cookies (aka Netscape type of cookies)

     */

    private boolean netscapeDomainMatches(String domain, String host)

    {

        if (domain == null || host == null) {

            return false;

        }

        // if there's no embedded dot in domain and domain is not .local

        boolean isLocalDomain = ".local".equalsIgnoreCase(domain);

        int embeddedDotInDomain = domain.indexOf('.');

        if (embeddedDotInDomain == 0) {

            embeddedDotInDomain = domain.indexOf('.', 1);

        }

        if (!isLocalDomain && (embeddedDotInDomain == -1 || embeddedDotInDomain == domain.length() - 1)) {

            return false;

        }

        // if the host name contains no dot and the domain name is .local

        int firstDotInHost = host.indexOf('.');

        if (firstDotInHost == -1 && isLocalDomain) {

            return true;

        }

        int domainLength = domain.length();

        int lengthDiff = host.length() - domainLength;

        if (lengthDiff == 0) {

            // if the host name and the domain name are just string-compare equal

            return host.equalsIgnoreCase(domain);

        } else if (lengthDiff > 0) {

            // need to check H & D component

            String H = host.substring(0, lengthDiff);

            String D = host.substring(lengthDiff);

            return (D.equalsIgnoreCase(domain));

        } else if (lengthDiff == -1) {

            // if domain is actually .host

            return (domain.charAt(0) == '.' &&

                    host.equalsIgnoreCase(domain.substring(1)));

        }

        return false;

    }

    private void getInternal1(List<HttpCookie> cookies, Map<String, List<HttpCookie>> cookieIndex,

            String host, boolean secureLink) {

        // Use a separate list to handle cookies that need to be removed so

        // that there is no conflict with iterators.

        ArrayList<HttpCookie> toRemove = new ArrayList<>();

        for (Map.Entry<String, List<HttpCookie>> entry : cookieIndex.entrySet()) {

            String domain = entry.getKey();

            List<HttpCookie> lst = entry.getValue();

            for (HttpCookie c : lst) {

                if ((c.getVersion() == 0 && netscapeDomainMatches(domain, host)) ||

                        (c.getVersion() == 1 && HttpCookie.domainMatches(domain, host))) {

                    if ((cookieJar.indexOf(c) != -1)) {

                        // the cookie still in main cookie store

                        if (!c.hasExpired()) {

                            // don't add twice and make sure it's the proper

                            // security level

                            if ((secureLink || !c.getSecure()) &&

                                    !cookies.contains(c)) {

                                cookies.add(c);

                            }

                        } else {

                            toRemove.add(c);

                        }

                    } else {

                        // the cookie has been removed from main store,

                        // so also remove it from domain indexed store

                        toRemove.add(c);

                    }

                }

            }

            // Clear up the cookies that need to be removed

            for (HttpCookie c : toRemove) {

                lst.remove(c);

                cookieJar.remove(c);

            }

            toRemove.clear();

        }

    }

    // @param cookies           [OUT] contains the found cookies

    // @param cookieIndex       the index

    // @param comparator        the prediction to decide whether or not

    //                          a cookie in index should be returned

    private <T> void getInternal2(List<HttpCookie> cookies,

                                Map<T, List<HttpCookie>> cookieIndex,

                                Comparable<T> comparator, boolean secureLink)

    {

        for (T index : cookieIndex.keySet()) {

            if (comparator.compareTo(index) == 0) {

                List<HttpCookie> indexedCookies = cookieIndex.get(index);

                // check the list of cookies associated with this domain

                if (indexedCookies != null) {

                    Iterator<HttpCookie> it = indexedCookies.iterator();

                    while (it.hasNext()) {

                        HttpCookie ck = it.next();

                        if (cookieJar.indexOf(ck) != -1) {

                            // the cookie still in main cookie store

                            if (!ck.hasExpired()) {

                                // don't add twice

                                if ((secureLink || !ck.getSecure()) &&

                                        !cookies.contains(ck))

                                    cookies.add(ck);

                            } else {

                                it.remove();

                                cookieJar.remove(ck);

                            }

                        } else {

                            // the cookie has been removed from main store,

                            // so also remove it from domain indexed store

                            it.remove();

                        }

                    }

                } // end of indexedCookies != null

            } // end of comparator.compareTo(index) == 0

        } // end of cookieIndex iteration

    }

    // add 'cookie' indexed by 'index' into 'indexStore'

    private <T> void addIndex(Map<T, List<HttpCookie>> indexStore,

                              T index,

                              HttpCookie cookie)

    {

        if (index != null) {

            List<HttpCookie> cookies = indexStore.get(index);

            if (cookies != null) {

                // there may already have the same cookie, so remove it first

                cookies.remove(cookie);

                cookies.add(cookie);

            } else {

                cookies = new ArrayList<>();

                cookies.add(cookie);

                indexStore.put(index, cookies);

            }

        }

    }

    //

    // for cookie purpose, the effective uri should only be http://host

    // the path will be taken into account when path-match algorithm applied

    //

    private URI getEffectiveURI(URI uri) {

        URI effectiveURI = null;

        try {

            effectiveURI = new URI("http",

                                   uri.getHost(),

                                   null,  // path component

                                   null,  // query component

                                   null   // fragment component

                                  );

        } catch (URISyntaxException ignored) {

            effectiveURI = uri;

        }

        return effectiveURI;

    }

}