/*
    * ====================================================================
    * 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.client.protocol;
  
  import java.io.IOException;
  import java.util.Queue;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.http.Header;
  import org.apache.http.HttpException;
  import org.apache.http.HttpRequest;
  import org.apache.http.HttpRequestInterceptor;
  import org.apache.http.auth.AuthOption;
  import org.apache.http.auth.AuthScheme;
  import org.apache.http.auth.AuthState;
  import org.apache.http.auth.AuthenticationException;
  import org.apache.http.auth.ContextAwareAuthScheme;
  import org.apache.http.auth.Credentials;
  import org.apache.http.protocol.HttpContext;
  
  abstract class RequestAuthenticationBase implements HttpRequestInterceptor {
  
      final Log log = LogFactory.getLog(getClass());
  
      public RequestAuthenticationBase() {
          super();
      }
  
      void process(
              final AuthState authState,
              final HttpRequest request,
              final HttpContext context) throws HttpException, IOException {
          AuthScheme authScheme = authState.getAuthScheme();
          Credentials creds = authState.getCredentials();
          switch (authState.getState()) {
          case FAILURE:
              return;
          case SUCCESS:
              ensureAuthScheme(authScheme);
              if (authScheme.isConnectionBased()) {
                  return;
              }
              break;
          case CHALLENGED:
              Queue<AuthOption> authOptions = authState.getAuthOptions();
              if (authOptions != null) {
                  while (!authOptions.isEmpty()) {
                      AuthOption authOption = authOptions.remove();
                      authScheme = authOption.getAuthScheme();
                      creds = authOption.getCredentials();
                      authState.update(authScheme, creds);
                      if (this.log.isDebugEnabled()) {
                          this.log.debug("Generating response to an authentication challenge using "
                                  + authScheme.getSchemeName() + " scheme");
                      }
                      try {
                          Header header = authenticate(authScheme, creds, request, context);
                          request.addHeader(header);
                          break;
                      } catch (AuthenticationException ex) {
                          if (this.log.isWarnEnabled()) {
                              this.log.warn(authScheme + " authentication error: " + ex.getMessage());
                          }
                      }
                  }
                  return;
              } else {
                  ensureAuthScheme(authScheme);
              }
          }
          if (authScheme != null) {
              try {
                  Header header = authenticate(authScheme, creds, request, context);
                 request.addHeader(header);
             } catch (AuthenticationException ex) {
                 if (this.log.isErrorEnabled()) {
                     this.log.error(authScheme + " authentication error: " + ex.getMessage());
                 }
             }
         }
     }
 
     private void ensureAuthScheme(final AuthScheme authScheme) {
         if (authScheme == null) {
             throw new IllegalStateException("Auth scheme is not set");
         }
     }
 
     @SuppressWarnings("deprecation")
     private Header authenticate(
             final AuthScheme authScheme,
             final Credentials creds,
             final HttpRequest request,
             final HttpContext context) throws AuthenticationException {
         if (authScheme == null) {
             throw new IllegalStateException("Auth state object is null");
         }
         if (authScheme instanceof ContextAwareAuthScheme) {
             return ((ContextAwareAuthScheme) authScheme).authenticate(creds, request, context);
         } else {
             return authScheme.authenticate(creds, request);
         }
     }
 
 }