HttpClientConverter

/*
 * Copyright (c) 2002-2026 Gargoyle Software Inc.
 *
 * Licensed 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
 * https://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.
 */
package org.htmlunit.httpclient;

import java.net.IDN;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Set;

import org.apache.http.conn.util.InetAddressUtils;
import org.apache.http.conn.util.PublicSuffixMatcher;
import org.apache.http.conn.util.PublicSuffixMatcherLoader;
import org.apache.http.cookie.ClientCookie;
import org.apache.http.cookie.Cookie;
import org.apache.http.cookie.CookieOrigin;
import org.apache.http.cookie.CookieSpec;
import org.apache.http.cookie.MalformedCookieException;
import org.apache.http.impl.cookie.BasicClientCookie;
import org.apache.http.message.BufferedHeader;
import org.apache.http.util.CharArrayBuffer;
import org.htmlunit.BrowserVersion;
import org.htmlunit.util.UrlUtils;

/**
 * Helper methods to convert from/to HttpClient.
 *
 * @author Ronald Brill
 */
public final class HttpClientConverter {

    private static final PublicSuffixMatcher PUBLIC_SUFFIX_MATCHER = PublicSuffixMatcherLoader.getDefault();

    private HttpClientConverter() {
        // util class
    }

    /**
     * Returns the "registrable domain" (effective TLD+1) for the given host, per the
     * public suffix list (https://publicsuffix.org/). Backed by Apache HttpClient's own
     * {@link PublicSuffixMatcher}, already on the classpath as part of the httpclient
     * dependency this class already uses elsewhere for cookie handling - no new
     * dependency needed, and it avoids the wrong results a naive "last two labels"
     * heuristic would give for domains under multi-part public suffixes (e.g. a
     * {@code co.uk}-style suffix, or a private-section entry like {@code github.io}).
     * <p>
     * Note this is deliberately unrelated to {@link HtmlUnitDomainHandler}'s cookie
     * domain-matching: RFC 6265 cookie domain-match is a simple suffix/subdomain check
     * against a single cookie-supplied domain, not a registrable-domain computation
     * between two hosts, so there is nothing to share between the two.
     * </p>
     * @param host the host part of a URL
     * @return the registrable domain, or the host itself if it doesn't have one (e.g.
     *         a bare public suffix, a single-label host like {@code localhost}, or an
     *         IP address - which per the HTML "obtain a site" algorithm is always its
     *         own site, never run through the public suffix list at all)
     */
    public static String registrableDomain(final String host) {
        if (InetAddressUtils.isIPv4Address(host) || InetAddressUtils.isIPv6Address(host)) {
            return host;
        }
        final String domainRoot = IDN.toASCII(PUBLIC_SUFFIX_MATCHER.getDomainRoot(host));
        return domainRoot == null ? host : domainRoot;
    }

    /**
     * Helper that builds a CookieOrigin.
     * @param url the url to be used
     * @return the new CookieOrigin
     */
    public static CookieOrigin buildCookieOrigin(final URL url) {
        final URL normalizedUrl = replaceForCookieIfNecessary(url);

        int port = normalizedUrl.getPort();
        if (port == -1) {
            port = normalizedUrl.getDefaultPort();
        }

        return new CookieOrigin(
                normalizedUrl.getHost(),
                port,
                normalizedUrl.getPath(),
                "https".equals(normalizedUrl.getProtocol()));
    }

    /**
     * {@link CookieOrigin} doesn't like empty hosts and negative ports,
     * but these things happen if we're dealing with a local file.
     * This method allows us to work around this limitation in HttpClient by feeding it a bogus host and port.
     *
     * @param url the URL to replace if necessary
     * @return the replacement URL, or the original URL if no replacement was necessary
     */
    public static URL replaceForCookieIfNecessary(URL url) {
        final String protocol = url.getProtocol();
        final boolean file = "file".equals(protocol);
        if (file) {
            try {
                url = UrlUtils.getUrlWithNewHostAndPort(url,
                        HtmlUnitBrowserCompatCookieSpec.LOCAL_FILESYSTEM_DOMAIN, 0);
            }
            catch (final MalformedURLException e) {
                throw new RuntimeException(e);
            }
        }
        return url;
    }

    /**
     * Parses the specified cookie string into HtmlUnit cookie objects.
     *
     * @param cookieString the {@code Set-Cookie} header value to parse
     * @param pageUrl the URL of the page from which the cookie originates
     * @param browserVersion the browser version used to determine cookie parsing behavior
     * @return a list of parsed {@link org.htmlunit.http.Cookie} instances
     * @throws MalformedCookieException if the cookie string does not conform to the cookie specification
     */
    public static List<org.htmlunit.http.Cookie> parseCookie(final String cookieString, final URL pageUrl,
                                                             final BrowserVersion browserVersion)
            throws MalformedCookieException {
        final CharArrayBuffer buffer = new CharArrayBuffer(cookieString.length() + 22);
        buffer.append("Set-Cookie: ");
        buffer.append(cookieString);

        final CookieSpec cookieSpec = new HtmlUnitBrowserCompatCookieSpec(browserVersion);
        final List<Cookie> cookies = cookieSpec.parse(new BufferedHeader(buffer), buildCookieOrigin(pageUrl));

        final List<org.htmlunit.http.Cookie> htmlUnitCookies = new ArrayList<>(cookies.size());
        for (final Cookie cookie : cookies) {
            final org.htmlunit.http.Cookie htmlUnitCookie = new HttpClientCookie((ClientCookie) cookie);
            htmlUnitCookies.add(htmlUnitCookie);
        }
        return htmlUnitCookies;
    }

    /**
     * Converts the specified collection of cookies into a collection of HttpClient cookies.
     * @param cookies the cookies to be converted
     * @return the specified cookies, as HttpClient cookies
     */
    public static List<Cookie> toHttpClient(final Collection<org.htmlunit.http.Cookie> cookies) {
        final ArrayList<Cookie> array = new ArrayList<>(cookies.size());
        for (final org.htmlunit.http.Cookie cookie : cookies) {
            array.add(toHttpClient(cookie));
        }
        return array;
    }

    /**
     * Adds all matching cookies to the provided set.
     * @param cookies the cookies to select from
     * @param normalizedUrl the url to match against
     * @param browserVersion the {@link BrowserVersion}
     * @param matches the set to add
     */
    public static void addMatching(final Set<org.htmlunit.http.Cookie> cookies,
            final URL normalizedUrl, final BrowserVersion browserVersion,
            final Set<org.htmlunit.http.Cookie> matches) {
        if (!cookies.isEmpty()) {
            final CookieOrigin cookieOrigin = HttpClientConverter.buildCookieOrigin(normalizedUrl);
            final CookieSpec cookieSpec = new HtmlUnitBrowserCompatCookieSpec(browserVersion);
            for (final org.htmlunit.http.Cookie cookie : cookies) {
                if (cookieSpec.match(toHttpClient(cookie), cookieOrigin)) {
                    matches.add(cookie);
                }
            }
        }
    }

    private static ClientCookie toHttpClient(final org.htmlunit.http.Cookie cookie) {
        if (cookie instanceof HttpClientCookie) {
            return ((HttpClientCookie) cookie).getHttpClientCookie();
        }

        final BasicClientCookie httpClientCookie = new BasicClientCookie(cookie.getName(),
                cookie.getValue() == null ? "" : cookie.getValue());

        httpClientCookie.setDomain(cookie.getDomain());
        // BasicDomainHandler.match(Cookie, CookieOrigin) checks the attribute also (see #333)
        httpClientCookie.setAttribute(ClientCookie.DOMAIN_ATTR, cookie.getDomain());

        httpClientCookie.setPath(cookie.getPath());
        httpClientCookie.setExpiryDate(cookie.getExpires());

        httpClientCookie.setSecure(cookie.isSecure());
        if (cookie.isHttpOnly()) {
            httpClientCookie.setAttribute("httponly", "true");
        }

        if (cookie.getSameSite() != null) {
            httpClientCookie.setAttribute("samesite", cookie.getSameSite());
        }

        return httpClientCookie;
    }
}