/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/**

 * 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 com.sun.org.apache.xml.internal.security.transforms.implementations;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.OutputStream;

import com.sun.org.apache.xml.internal.security.c14n.CanonicalizationException;

import com.sun.org.apache.xml.internal.security.c14n.implementations.Canonicalizer20010315Excl;

import com.sun.org.apache.xml.internal.security.c14n.implementations.Canonicalizer20010315ExclOmitComments;

import com.sun.org.apache.xml.internal.security.exceptions.XMLSecurityException;

import com.sun.org.apache.xml.internal.security.signature.XMLSignatureInput;

import com.sun.org.apache.xml.internal.security.transforms.TransformSpi;

import com.sun.org.apache.xml.internal.security.transforms.Transforms;

import com.sun.org.apache.xml.internal.security.transforms.params.InclusiveNamespaces;

import com.sun.org.apache.xml.internal.security.utils.XMLUtils;

import org.w3c.dom.Element;

import org.w3c.dom.Node;

/**

 * Class TransformC14NExclusive

 *

 */

public class TransformC14NExclusive extends TransformSpi {

    /**

     * {@inheritDoc}

     */

    @Override

    protected String engineGetURI() {

        return Transforms.TRANSFORM_C14N_EXCL_OMIT_COMMENTS;

    }

    /**

     * {@inheritDoc}

     */

    @Override

    protected XMLSignatureInput enginePerformTransform(

        XMLSignatureInput input, OutputStream os, Element transformElement,

        String baseURI, boolean secureValidation

    ) throws CanonicalizationException {

        try {

            String inclusiveNamespaces = null;

            if (length(transformElement,

                InclusiveNamespaces.ExclusiveCanonicalizationNamespace,

                InclusiveNamespaces._TAG_EC_INCLUSIVENAMESPACES) == 1

            ) {

                Element inclusiveElement =

                    XMLUtils.selectNode(

                        transformElement.getFirstChild(),

                        InclusiveNamespaces.ExclusiveCanonicalizationNamespace,

                        InclusiveNamespaces._TAG_EC_INCLUSIVENAMESPACES,

                        0

                    );

                inclusiveNamespaces =

                    new InclusiveNamespaces(

                        inclusiveElement, baseURI).getInclusiveNamespaces();

            }

            Canonicalizer20010315Excl c14n = getCanonicalizer();

            if (os == null) {

                try (ByteArrayOutputStream writer = new ByteArrayOutputStream()) {

                    c14n.engineCanonicalize(input, inclusiveNamespaces, writer, secureValidation);

                    writer.flush();

                    XMLSignatureInput output = new XMLSignatureInput(writer.toByteArray());

                    output.setSecureValidation(secureValidation);

                    return output;

                } catch (IOException ex) {

                    throw new CanonicalizationException("empty", new Object[] {ex.getMessage()});

                }

            } else {

                c14n.engineCanonicalize(input, inclusiveNamespaces, os, secureValidation);

                XMLSignatureInput output = new XMLSignatureInput((byte[])null);

                output.setSecureValidation(secureValidation);

                output.setOutputStream(os);

                return output;

            }

        } catch (XMLSecurityException ex) {

            throw new CanonicalizationException(ex);

        }

    }

    protected Canonicalizer20010315Excl getCanonicalizer() {

        return new Canonicalizer20010315ExclOmitComments();

    }

    /**

     * Method length

     *

     * @param namespace

     * @param localname

     * @return the number of elements {namespace}:localname under this element

     */

    private int length(Element element, String namespace, String localname) {

        int number = 0;

        Node sibling = element.getFirstChild();

        while (sibling != null) {

            if (localname.equals(sibling.getLocalName())

                && namespace.equals(sibling.getNamespaceURI())) {

                number++;

            }

            sibling = sibling.getNextSibling();

        }

        return number;

    }

}