/*

 * 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.c14n.helper;

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

import org.w3c.dom.Attr;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import org.w3c.dom.NamedNodeMap;

/**

 * Temporary swapped static functions from the normalizer Section

 *

 */

public final class C14nHelper {

    /**

     * Constructor C14nHelper

     *

     */

    private C14nHelper() {

        // don't allow instantiation

    }

    /**

     * Method namespaceIsRelative

     *

     * @param namespace

     * @return true if the given namespace is relative.

     */

    public static boolean namespaceIsRelative(Attr namespace) {

        return !namespaceIsAbsolute(namespace);

    }

    /**

     * Method namespaceIsRelative

     *

     * @param namespaceValue

     * @return true if the given namespace is relative.

     */

    public static boolean namespaceIsRelative(String namespaceValue) {

        return !namespaceIsAbsolute(namespaceValue);

    }

    /**

     * Method namespaceIsAbsolute

     *

     * @param namespace

     * @return true if the given namespace is absolute.

     */

    public static boolean namespaceIsAbsolute(Attr namespace) {

        return namespaceIsAbsolute(namespace.getValue());

    }

    /**

     * Method namespaceIsAbsolute

     *

     * @param namespaceValue

     * @return true if the given namespace is absolute.

     */

    public static boolean namespaceIsAbsolute(String namespaceValue) {

        // assume empty namespaces are absolute

        if (namespaceValue.length() == 0) {

            return true;

        }

        return namespaceValue.indexOf(':') > 0;

    }

    /**

     * This method throws an exception if the Attribute value contains

     * a relative URI.

     *

     * @param attr

     * @throws CanonicalizationException

     */

    public static void assertNotRelativeNS(Attr attr) throws CanonicalizationException {

        if (attr == null) {

            return;

        }

        String nodeAttrName = attr.getNodeName();

        boolean definesDefaultNS = "xmlns".equals(nodeAttrName);

        boolean definesNonDefaultNS = nodeAttrName.startsWith("xmlns:");

        if ((definesDefaultNS || definesNonDefaultNS) && namespaceIsRelative(attr)) {

            String parentName = attr.getOwnerElement().getTagName();

            String attrValue = attr.getValue();

            Object exArgs[] = { parentName, nodeAttrName, attrValue };

            throw new CanonicalizationException(

                "c14n.Canonicalizer.RelativeNamespace", exArgs

            );

        }

    }

    /**

     * This method throws a CanonicalizationException if the supplied Document

     * is not able to be traversed using a TreeWalker.

     *

     * @param document

     * @throws CanonicalizationException

     */

    public static void checkTraversability(Document document)

        throws CanonicalizationException {

        if (!document.isSupported("Traversal", "2.0")) {

            Object exArgs[] = {document.getImplementation().getClass().getName() };

            throw new CanonicalizationException(

                "c14n.Canonicalizer.TraversalNotSupported", exArgs

            );

        }

    }

    /**

     * This method throws a CanonicalizationException if the supplied Element

     * contains any relative namespaces.

     *

     * @param ctxNode

     * @throws CanonicalizationException

     * @see C14nHelper#assertNotRelativeNS(Attr)

     */

    public static void checkForRelativeNamespace(Element ctxNode)

        throws CanonicalizationException {

        if (ctxNode != null) {

            NamedNodeMap attributes = ctxNode.getAttributes();

            int length = attributes.getLength();

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

                C14nHelper.assertNotRelativeNS((Attr) attributes.item(i));

            }

        } else {

            throw new CanonicalizationException("Called checkForRelativeNamespace() on null");

        }

    }

}