/**
    * 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.transformer;
  
  import org.apache.wss4j.common.ext.Attachment;
  import org.apache.wss4j.common.util.CRLFOutputStream;
  import org.apache.xml.security.exceptions.XMLSecurityException;
  import org.apache.xml.security.stax.ext.XMLSecurityConstants;
  import org.apache.xml.security.stax.ext.stax.XMLSecEvent;
  import org.apache.xml.security.stax.impl.transformer.TransformIdentity;
  import org.apache.xml.security.stax.impl.transformer.canonicalizer.Canonicalizer20010315_ExclOmitCommentsTransformer;
  
  import javax.xml.stream.XMLStreamException;
  
  import java.io.InputStream;
  import java.util.Map;
  
  public class AttachmentContentSignatureTransform extends TransformIdentity {
  
      public static final String ATTACHMENT = "attachment";
  
      private Attachment attachment;
  
      @Override
      public XMLSecurityConstants.TransformMethod getPreferredTransformMethod(XMLSecurityConstants.TransformMethod forInput) {
          switch (forInput) {
              case XMLSecEvent:
                  return XMLSecurityConstants.TransformMethod.InputStream;
              case InputStream:
                  return XMLSecurityConstants.TransformMethod.InputStream;
              default:
                  throw new IllegalArgumentException("Unsupported class " + forInput.name());
          }
      }
  
      @Override
      public void setProperties(Map<String, Object> properties) throws XMLSecurityException {
          this.attachment = (Attachment) properties.get(ATTACHMENT);
      }
  
      protected Attachment getAttachment() {
          return attachment;
      }
  
      /*
               * http://docs.oasis-open.org/wss-m/wss/v1.1.1/os/wss-SwAProfile-v1.1.1-os.html
               * 5.2 Referencing Attachments
               * This profile assumes, since it is not defined in RFC 2396 Section 4.2, that
               * all cid: references are not same-document references and that therefore, under
               * XMLDSIG, dereferencing a cid: URI always yields an octet stream as input to the
               * transform chain [RFC2396], [XMLDSIG].
               */
      @Override
      public void transform(XMLSecEvent xmlSecEvent) throws XMLStreamException {
          throw new UnsupportedOperationException("transform(XMLSecEvent) not allowed");
      }
  
      @Override
      public void transform(InputStream inputStream) throws XMLStreamException {
          String mimeType = getAttachment().getMimeType();
  
          if (mimeType != null
              && (mimeType.matches("(?i)(text/xml).*")
                  || mimeType.matches("(?i)(application/xml).*")
                  || mimeType.matches("(?i)(application|image)/.*\\+xml.*"))) {
              /* 5.4.2:
               * Content of an XML Content-Type MUST be XML canonicalized using
               * Exclusive XML Canonicalization without comments, as specified by
               * the URI http://www.w3.org/2001/10/xml-exc-c14n# [Excl-Canon].
               * The reason for requiring Exclusive Canonicalization is that many
               * implementations will support Exclusive Canonicalization for other
               * XML Signature purposes, since this form of canonicalization
               * supports context changes. The InclusiveNamespace PrefixList
               * attribute SHOULD be empty or not present.
               */
              Canonicalizer20010315_ExclOmitCommentsTransformer canon =
                      new Canonicalizer20010315_ExclOmitCommentsTransformer();
              try {
                  canon.setOutputStream(getOutputStream());
              } catch (XMLSecurityException e) {
                  throw new XMLStreamException(e);
              }
              canon.transform(inputStream);
 
         } else if (mimeType != null && mimeType.matches("(?i)(text/).*")) {
             CRLFOutputStream crlfOutputStream = new CRLFOutputStream(getOutputStream());    //NOPMD
             try {
                 setOutputStream(crlfOutputStream);
             } catch (XMLSecurityException e) {
                 throw new XMLStreamException(e);
             }
             super.transform(inputStream);
         } else {
             super.transform(inputStream);
         }
     }
 }