/*

 * 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.

 */

/*

 * Copyright (c) 2005, 2018, Oracle and/or its affiliates. All rights reserved.

 */

/*

 * $Id: DOMXPathTransform.java 1788465 2017-03-24 15:10:51Z coheigea $

 */

package org.jcp.xml.dsig.internal.dom;

import javax.xml.crypto.*;

import javax.xml.crypto.dsig.*;

import javax.xml.crypto.dsig.spec.TransformParameterSpec;

import javax.xml.crypto.dsig.spec.XPathFilterParameterSpec;

import java.security.InvalidAlgorithmParameterException;

import java.util.HashMap;

import java.util.Map;

import java.util.Set;

import org.w3c.dom.Attr;

import org.w3c.dom.Element;

import org.w3c.dom.NamedNodeMap;

/**

 * DOM-based implementation of XPath Filtering Transform.

 * (Uses Apache XML-Sec Transform implementation)

 *

 */

public final class DOMXPathTransform extends ApacheTransform {

    @Override

    public void init(TransformParameterSpec params)

        throws InvalidAlgorithmParameterException

    {

        if (params == null) {

            throw new InvalidAlgorithmParameterException("params are required");

        } else if (!(params instanceof XPathFilterParameterSpec)) {

            throw new InvalidAlgorithmParameterException

                ("params must be of type XPathFilterParameterSpec");

        }

        this.params = params;

    }

    @Override

    public void init(XMLStructure parent, XMLCryptoContext context)

        throws InvalidAlgorithmParameterException

    {

        super.init(parent, context);

        unmarshalParams(DOMUtils.getFirstChildElement(transformElem));

    }

    private void unmarshalParams(Element paramsElem) {

        String xPath = paramsElem.getFirstChild().getNodeValue();

        // create a Map of namespace prefixes

        NamedNodeMap attributes = paramsElem.getAttributes();

        if (attributes != null) {

            int length = attributes.getLength();

            Map<String, String> namespaceMap =

                new HashMap<>(length);

            for (int i = 0; i < length; i++) {

                Attr attr = (Attr)attributes.item(i);

                String prefix = attr.getPrefix();

                if (prefix != null && "xmlns".equals(prefix)) {

                    namespaceMap.put(attr.getLocalName(), attr.getValue());

                }

            }

            this.params = new XPathFilterParameterSpec(xPath, namespaceMap);

        } else {

            this.params = new XPathFilterParameterSpec(xPath);

        }

    }

    @Override

    public void marshalParams(XMLStructure parent, XMLCryptoContext context)

        throws MarshalException

    {

        super.marshalParams(parent, context);

        XPathFilterParameterSpec xp =

            (XPathFilterParameterSpec)getParameterSpec();

        Element xpathElem = DOMUtils.createElement(ownerDoc, "XPath",

             XMLSignature.XMLNS, DOMUtils.getSignaturePrefix(context));

        xpathElem.appendChild(ownerDoc.createTextNode(xp.getXPath()));

        // add namespace attributes, if necessary

        @SuppressWarnings("unchecked")

        Set<Map.Entry<String, String>> entries =

            xp.getNamespaceMap().entrySet();

        for (Map.Entry<String, String> entry : entries) {

            xpathElem.setAttributeNS("http://www.w3.org/2000/xmlns/", "xmlns:" +

                                     entry.getKey(),

                                     entry.getValue());

        }

        transformElem.appendChild(xpathElem);

    }

}