/**
    * 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.
   */
  package org.apache.wss4j.stax.impl.processor.input;
  
  import java.util.Deque;
  
  import javax.xml.stream.XMLStreamException;
  import javax.xml.stream.events.Attribute;
  
  import org.apache.wss4j.common.ext.WSSecurityException;
  import org.apache.wss4j.stax.ext.WSInboundSecurityContext;
  import org.apache.wss4j.stax.ext.WSSConstants;
  import org.apache.wss4j.stax.ext.WSSSecurityProperties;
  import org.apache.xml.security.binding.xmlenc.ReferenceList;
  import org.apache.xml.security.binding.xmlenc.ReferenceType;
  import org.apache.xml.security.exceptions.XMLSecurityException;
  import org.apache.xml.security.stax.ext.AbstractInputProcessor;
  import org.apache.xml.security.stax.ext.AbstractInputSecurityHeaderHandler;
  import org.apache.xml.security.stax.ext.InputProcessor;
  import org.apache.xml.security.stax.ext.InputProcessorChain;
  import org.apache.xml.security.stax.ext.XMLSecurityConstants;
  import org.apache.xml.security.stax.ext.XMLSecurityProperties;
  import org.apache.xml.security.stax.ext.stax.XMLSecEvent;
  import org.apache.xml.security.stax.ext.stax.XMLSecStartElement;
  
  /**
   * Processor for the EncryptedData XML Structure in the security header.
   * Note, this handler is special in respect to when it is called: it is triggered by the
   * EncryptedData StartElement and not when the EndElement occurs. @see comments in SecurityHeaderInputProcessort
   */
  public class EncryptedDataInputHandler extends AbstractInputSecurityHeaderHandler {
  
      @Override
      public void handle(final InputProcessorChain inputProcessorChain, final XMLSecurityProperties securityProperties,
                         final Deque<XMLSecEvent> eventQueue, final Integer index) throws XMLSecurityException {
  
          XMLSecEvent xmlSecEvent = eventQueue.pollFirst();
          if (!(xmlSecEvent instanceof XMLSecStartElement)) {
              throw new WSSecurityException(WSSecurityException.ErrorCode.FAILURE);
          }
          final XMLSecStartElement encryptedDataElement = xmlSecEvent.asStartElement();
          final Attribute idAttribute = encryptedDataElement.getAttributeByName(XMLSecurityConstants.ATT_NULL_Id);
  
          DecryptInputProcessor decryptInputProcessor =
                  new DecryptInputProcessor(null, new ReferenceList(), (WSSSecurityProperties) securityProperties,
                          (WSInboundSecurityContext) inputProcessorChain.getSecurityContext()) {
  
                      @Override
                      protected ReferenceType matchesReferenceId(XMLSecStartElement xmlSecStartElement) {
                          if (xmlSecStartElement == encryptedDataElement) {
                              ReferenceType referenceType = new ReferenceType();
                              if (idAttribute != null) {
                                  final String uri = idAttribute.getValue();
                                  referenceType.setURI("#" + uri);
                                  inputProcessorChain.getSecurityContext().putAsList(WSSConstants.PROP_ENCRYPTED_DATA_REFS, uri);
                              }
                              return referenceType;
                          }
                          return null;
                      }
                  };
          inputProcessorChain.addProcessor(decryptInputProcessor);
  
          //replay the EncryptedData event for the DecryptInputProcessor:
          InputProcessor tmpProcessor = new AbstractInputProcessor(securityProperties) {
              @Override
              public XMLSecEvent processHeaderEvent(InputProcessorChain inputProcessorChain)
                  throws XMLStreamException, XMLSecurityException {
                  inputProcessorChain.removeProcessor(this);
                  return encryptedDataElement;
              }
  
              @Override
              public XMLSecEvent processEvent(InputProcessorChain inputProcessorChain)
                  throws XMLStreamException, XMLSecurityException {
                  inputProcessorChain.removeProcessor(this);
                  return encryptedDataElement;
              }
          };
          tmpProcessor.addBeforeProcessor(decryptInputProcessor);
          inputProcessorChain.addProcessor(tmpProcessor);
      }
  }