/*
    * Copyright 2009 the original author or authors.
    *
    * 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
    *
    *     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.
   */
  package org.openehealth.ipf.commons.ihe.ws.cxf;
  
  import org.apache.cxf.binding.soap.SoapHeader;
  import org.apache.cxf.binding.soap.SoapMessage;
  import org.apache.cxf.binding.soap.interceptor.AbstractSoapInterceptor;
  import org.apache.cxf.ext.logging.LoggingOutInterceptor;
  import org.apache.cxf.headers.Header;
  import org.apache.cxf.interceptor.Fault;
  import org.apache.cxf.phase.Phase;
  import org.apache.cxf.ws.addressing.soap.MAPCodec;
  
  import javax.xml.namespace.QName;
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * CXF Interceptor to tag SOAP headers with an {@code mustUnderstand} flag. 
   * @author Jens Riemschneider
   */
  public class MustUnderstandDecoratorInterceptor extends AbstractSoapInterceptor {
      private final List<QName> mustUnderstandHeaders = new ArrayList<>();
  
      /**
       * Constructs the interceptor.
       */
      public MustUnderstandDecoratorInterceptor() {
          super(Phase.WRITE);
          addAfter(MAPCodec.class.getName());
          addBefore(LoggingOutInterceptor.class.getName());
      }
  
      @Override
      public void handleMessage(SoapMessage message) throws Fault {
          List<Header> headers = message.getHeaders();
          for (QName name : mustUnderstandHeaders) {
              mustUnderstand(headers, name);
          }
      }
  
      /**
       * Adds a set of SOAP headers which are to be flagged 
       * with {@code mustUnderstand}.
       *  
       * @param headers
       *          the headers to flag, represented as Strings 
       */
      public void addHeaders(List<String> headers) {
          for (String header : headers) {
              int namespaceEnd = header.indexOf('}');
              String namespace = header.substring(1, namespaceEnd);
              String name = header.substring(namespaceEnd + 1);
              mustUnderstandHeaders.add(new QName(namespace, name));
          }
      }
  
      /**
       * Adds an item to the list of SOAP headers which  
       * are to be flagged with {@code mustUnderstand}.
       *  
       * @param header
       *          the header to flag.
       */
      public void addHeader(QName header) {
          mustUnderstandHeaders.add(header);
      }
      
      
      private Header getHeader(List<Header> headers, QName name) {
          for (Header header : headers) {
              if (header.getName().equals(name)) {
                  return header;
              }
          }
          return null;
      }
  
      private void mustUnderstand(List<Header> headers, QName name) {
          Header header = getHeader(headers, name);
          if (header == null) {
              return;
          }
  
          if (header instanceof SoapHeader) {
              SoapHeader soapHeader = (SoapHeader) header;
             soapHeader.setMustUnderstand(true);
             return;
         }
 
         headers.remove(header);
         SoapHeader newHeader = new SoapHeader(name, header.getObject());
         newHeader.setMustUnderstand(true);
         headers.add(newHeader);
     }
 }