/*
    * ====================================================================
    * 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.hc.client5.http.protocol;
  
  import java.io.IOException;
  import java.time.Instant;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.hc.client5.http.RouteInfo;
  import org.apache.hc.client5.http.config.RequestConfig;
  import org.apache.hc.client5.http.cookie.Cookie;
  import org.apache.hc.client5.http.cookie.CookieOrigin;
  import org.apache.hc.client5.http.cookie.CookieSpec;
  import org.apache.hc.client5.http.cookie.CookieSpecFactory;
  import org.apache.hc.client5.http.cookie.CookieStore;
  import org.apache.hc.client5.http.cookie.StandardCookieSpec;
  import org.apache.hc.core5.annotation.Contract;
  import org.apache.hc.core5.annotation.ThreadingBehavior;
  import org.apache.hc.core5.http.EntityDetails;
  import org.apache.hc.core5.http.Header;
  import org.apache.hc.core5.http.HttpException;
  import org.apache.hc.core5.http.HttpHeaders;
  import org.apache.hc.core5.http.HttpRequest;
  import org.apache.hc.core5.http.HttpRequestInterceptor;
  import org.apache.hc.core5.http.Method;
  import org.apache.hc.core5.http.config.Lookup;
  import org.apache.hc.core5.http.protocol.HttpContext;
  import org.apache.hc.core5.net.URIAuthority;
  import org.apache.hc.core5.util.Args;
  import org.apache.hc.core5.util.TextUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Request interceptor that matches cookies available in the current
   * {@link CookieStore} to the request being executed and generates
   * corresponding {@code Cookie} request headers.
   *
   * @since 4.0
   */
  @Contract(threading = ThreadingBehavior.STATELESS)
  public class RequestAddCookies implements HttpRequestInterceptor {
  
      /**
       * Default instance of {@link RequestAddCookies}.
       *
       * @since 5.2
       */
      public static final RequestAddCookies INSTANCE = new RequestAddCookies();
  
      private static final Logger LOG = LoggerFactory.getLogger(RequestAddCookies.class);
  
      public RequestAddCookies() {
          super();
      }
  
      @Override
      public void process(final HttpRequest request, final EntityDetails entity, final HttpContext context)
              throws HttpException, IOException {
          Args.notNull(request, "HTTP request");
          Args.notNull(context, "HTTP context");
  
          final String method = request.getMethod();
          if (Method.CONNECT.isSame(method) || Method.TRACE.isSame(method)) {
              return;
          }
  
          final Header cookieHeader = request.getHeader(HttpHeaders.COOKIE);
          // Check if a Cookie header is already present
          if (cookieHeader != null) {
              if (LOG.isDebugEnabled()) {
                  LOG.debug("Skipping cookie addition, Cookie header already present in the request");
              }
             // Skip adding cookies if the Cookie header is already present
             return;
         }
 
 
         final HttpClientContext clientContext = HttpClientContext.cast(context);
         final String exchangeId = clientContext.getExchangeId();
 
         // Obtain cookie store
         final CookieStore cookieStore = clientContext.getCookieStore();
         if (cookieStore == null) {
             if (LOG.isDebugEnabled()) {
                 LOG.debug("{} Cookie store not specified in HTTP context", exchangeId);
             }
             return;
         }
 
         // Obtain the registry of cookie specs
         final Lookup<CookieSpecFactory> registry = clientContext.getCookieSpecRegistry();
         if (registry == null) {
             if (LOG.isDebugEnabled()) {
                 LOG.debug("{} CookieSpec registry not specified in HTTP context", exchangeId);
             }
             return;
         }
 
         // Obtain the route (required)
         final RouteInfo route = clientContext.getHttpRoute();
         if (route == null) {
             if (LOG.isDebugEnabled()) {
                 LOG.debug("{} Connection route not set in the context", exchangeId);
             }
             return;
         }
 
         final RequestConfig config = clientContext.getRequestConfigOrDefault();
         String cookieSpecName = config.getCookieSpec();
         if (cookieSpecName == null) {
             cookieSpecName = StandardCookieSpec.STRICT;
         }
         if (LOG.isDebugEnabled()) {
             LOG.debug("{} Cookie spec selected: {}", exchangeId, cookieSpecName);
         }
 
         final URIAuthority authority = request.getAuthority();
         String path = request.getPath();
         if (TextUtils.isEmpty(path)) {
             path = "/";
         }
         String hostName = authority != null ? authority.getHostName() : null;
         if (hostName == null) {
             hostName = route.getTargetHost().getHostName();
         }
         int port = authority != null ? authority.getPort() : -1;
         if (port < 0) {
             port = route.getTargetHost().getPort();
         }
         final CookieOrigin cookieOrigin = new CookieOrigin(hostName, port, path, route.isSecure());
 
         // Get an instance of the selected cookie policy
         final CookieSpecFactory factory = registry.lookup(cookieSpecName);
         if (factory == null) {
             if (LOG.isDebugEnabled()) {
                 LOG.debug("{} Unsupported cookie spec: {}", exchangeId, cookieSpecName);
             }
             return;
         }
         final CookieSpec cookieSpec = factory.create(clientContext);
         // Get all cookies available in the HTTP state
         final List<Cookie> cookies = cookieStore.getCookies();
         // Find cookies matching the given origin
         final List<Cookie> matchedCookies = new ArrayList<>();
         final Instant now = Instant.now();
         boolean expired = false;
         for (final Cookie cookie : cookies) {
             if (!cookie.isExpired(now)) {
                 if (cookieSpec.match(cookie, cookieOrigin)) {
                     if (LOG.isDebugEnabled()) {
                         LOG.debug("{} Cookie {} match {}", exchangeId, cookie, cookieOrigin);
                     }
                     matchedCookies.add(cookie);
                 }
             } else {
                 if (LOG.isDebugEnabled()) {
                     LOG.debug("{} Cookie {} expired", exchangeId, cookie);
                 }
                 expired = true;
             }
         }
         // Per RFC 6265, 5.3
         // The user agent must evict all expired cookies if, at any time, an expired cookie
         // exists in the cookie store
         if (expired) {
             cookieStore.clearExpired(now);
         }
         // Generate Cookie request headers
         if (!matchedCookies.isEmpty()) {
             final List<Header> headers = cookieSpec.formatCookies(matchedCookies);
             for (final Header header : headers) {
                 request.addHeader(header);
             }
         }
 
         // Stick the CookieSpec and CookieOrigin instances to the HTTP context
         // so they could be obtained by the response interceptor
         clientContext.setCookieSpec(cookieSpec);
         clientContext.setCookieOrigin(cookieOrigin);
     }
 
 }