/**
    * Copyright 2005-2013 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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.kuali.rice.ksb.security.httpinvoker;
  
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  
  import org.apache.commons.codec.binary.Base64;
  import org.apache.commons.httpclient.HttpClient;
  import org.apache.commons.httpclient.methods.PostMethod;
  import org.kuali.rice.core.api.security.credentials.CredentialsSource;
  import org.kuali.rice.ksb.api.bus.ServiceConfiguration;
  import org.kuali.rice.ksb.messaging.KSBHttpInvokerRequestExecutor;
  import org.kuali.rice.ksb.security.credentials.UsernamePasswordCredentials;
  import org.springframework.remoting.httpinvoker.HttpInvokerClientConfiguration;
  import org.springframework.util.Assert;
  
  
  /**
   * Extension to {@link KSBHttpInvokerRequestExecutor} that retrieves
   * credentials from the CredentialsSource and places them in a BASIC HTTP
   * Authorization header.
   * 
   * @author Kuali Rice Team (rice.collab@kuali.org)
   * @since 0.9
   */
  public final class AuthenticationCommonsHttpInvokerRequestExecutor extends
      KSBHttpInvokerRequestExecutor {
  
      /**
       * Source of the credentials to pass via BASIC AUTH.
       */
      private final CredentialsSource credentialsSource;
  
      /**
       * Details about the service that the CredentialsSource may need.
       */
      private final ServiceConfiguration serviceConfiguration;
  
      /**
       * Constructor that accepts the CredentialsSource and Service Info.
       * 
       * @param credentialsSource the source of credentials.
       * @param serviceInfo information about the service.
       */
      public AuthenticationCommonsHttpInvokerRequestExecutor(final HttpClient httpClient, 
          final CredentialsSource credentialsSource, final ServiceConfiguration serviceConfiguration) {
          super(httpClient);
          Assert.notNull(credentialsSource, "credentialsSource cannot be null.");
          Assert.notNull(serviceConfiguration, "serviceConfiguration cannot be null.");
          this.credentialsSource = credentialsSource;
          this.serviceConfiguration = serviceConfiguration;
      }
  
      /**
       * Overridden to obtain the Credentials from the CredentialsSource and pass
       * them via HTTP BASIC Authorization.
       */
  
      protected void setRequestBody(final HttpInvokerClientConfiguration config,
          final PostMethod postMethod, final ByteArrayOutputStream baos) throws IOException {
      	final UsernamePasswordCredentials credentials = (UsernamePasswordCredentials) this.credentialsSource.getCredentials(this.serviceConfiguration.getEndpointUrl().toExternalForm());
  
          final String base64 = credentials.getUsername() + ":"
          + credentials.getPassword();
          postMethod.addRequestHeader("Authorization", "Basic " + new String(Base64.encodeBase64(base64.getBytes())));
  
          if (logger.isDebugEnabled()) {
              logger
                  .debug("HttpInvocation now presenting via BASIC authentication CredentialsSource-derived: "
                      + credentials.getUsername());
          }
          
          super.setRequestBody(config, postMethod, baos);
      }
  }