/*

 * Portions Copyright 2005 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

/*

 * ===========================================================================

 *

 * (C) Copyright IBM Corp. 2003 All Rights Reserved.

 *

 * ===========================================================================

 */

/*

 * $Id: DOMRetrievalMethod.java,v 1.24 2005/05/12 19:28:32 mullan Exp $

 */

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

import java.io.ByteArrayInputStream;

import java.net.URI;

import java.net.URISyntaxException;

import java.util.*;

import javax.xml.crypto.*;

import javax.xml.crypto.dsig.*;

import javax.xml.crypto.dom.DOMCryptoContext;

import javax.xml.crypto.dom.DOMURIReference;

import javax.xml.crypto.dsig.keyinfo.RetrievalMethod;

import javax.xml.parsers.*;

import org.w3c.dom.Attr;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import org.w3c.dom.Node;

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

/**

 * DOM-based implementation of RetrievalMethod.

 *

 * @author Sean Mullan

 * @author Joyce Leung

 */

public final class DOMRetrievalMethod extends DOMStructure

    implements RetrievalMethod, DOMURIReference {

    private final List transforms;

    private String uri;

    private String type;

    private Attr here;

    /**

     * Creates a <code>DOMRetrievalMethod</code> containing the specified

     * URIReference and List of Transforms.

     *

     * @param uri the URI

     * @param type the type

     * @param transforms a list of {@link Transform}s. The list is defensively

     *    copied to prevent subsequent modification. May be <code>null</code>

     *    or empty.

     * @throws IllegalArgumentException if the format of <code>uri</code> is

     *    invalid, as specified by Reference's URI attribute in the W3C

     *    specification for XML-Signature Syntax and Processing

     * @throws NullPointerException if <code>uriReference</code>

     *    is <code>null</code>

     * @throws ClassCastException if <code>transforms</code> contains any

     *    entries that are not of type {@link Transform}

     */

    public DOMRetrievalMethod(String uri, String type, List transforms) {

        if (uri == null) {

            throw new NullPointerException("uri cannot be null");

        }

        if (transforms == null || transforms.isEmpty()) {

            this.transforms = Collections.EMPTY_LIST;

        } else {

            List transformsCopy = new ArrayList(transforms);

            for (int i = 0, size = transformsCopy.size(); i < size; i++) {

                if (!(transformsCopy.get(i) instanceof Transform)) {

                    throw new ClassCastException

                        ("transforms["+i+"] is not a valid type");

                }

            }

            this.transforms = Collections.unmodifiableList(transformsCopy);

        }

        this.uri = uri;

        if ((uri != null) && (!uri.equals(""))) {

            try {

                new URI(uri);

            } catch (URISyntaxException e) {

                throw new IllegalArgumentException(e.getMessage());

            }

        }

        this.type = type;

    }

    /**

     * Creates a <code>DOMRetrievalMethod</code> from an element.

     *

     * @param rmElem a RetrievalMethod element

     */

    public DOMRetrievalMethod(Element rmElem, XMLCryptoContext context)

        throws MarshalException {

        // get URI and Type attributes

        uri = DOMUtils.getAttributeValue(rmElem, "URI");

        type = DOMUtils.getAttributeValue(rmElem, "Type");

        // get here node

        here = rmElem.getAttributeNodeNS(null, "URI");

        // get Transforms, if specified

        List transforms = new ArrayList();

        Element transformsElem = DOMUtils.getFirstChildElement(rmElem);

        if (transformsElem != null) {

            Element transformElem =

                DOMUtils.getFirstChildElement(transformsElem);

            while (transformElem != null) {

                transforms.add(new DOMTransform(transformElem, context));

                transformElem = DOMUtils.getNextSiblingElement(transformElem);

            }

        }

        if (transforms.isEmpty()) {

            this.transforms = Collections.EMPTY_LIST;

        } else {

            this.transforms = Collections.unmodifiableList(transforms);

        }

    }

    public String getURI() {

        return uri;

    }

    public String getType() {

        return type;

    }

    public List getTransforms() {

        return transforms;

    }

    public void marshal(Node parent, String dsPrefix, DOMCryptoContext context)

        throws MarshalException {

        Document ownerDoc = DOMUtils.getOwnerDocument(parent);

        Element rmElem = DOMUtils.createElement

            (ownerDoc, "RetrievalMethod", XMLSignature.XMLNS, dsPrefix);

        // add URI and Type attributes

        DOMUtils.setAttribute(rmElem, "URI", uri);

        DOMUtils.setAttribute(rmElem, "Type", type);

        // add Transforms elements

        if (!transforms.isEmpty()) {

            Element transformsElem = DOMUtils.createElement

                (ownerDoc, "Transforms", XMLSignature.XMLNS, dsPrefix);

            rmElem.appendChild(transformsElem);

            for (int i = 0, size = transforms.size(); i < size; i++) {

                ((DOMTransform) transforms.get(i)).marshal

                    (transformsElem, dsPrefix, context);

            }

        }

        parent.appendChild(rmElem);

        // save here node

        here = rmElem.getAttributeNodeNS(null, "URI");

    }

    public Node getHere() {

        return here;

    }

    public Data dereference(XMLCryptoContext context)

        throws URIReferenceException {

        if (context == null) {

            throw new NullPointerException("context cannot be null");

        }

        /*

         * If URIDereferencer is specified in context; use it, otherwise use

         * built-in.

         */

        URIDereferencer deref = context.getURIDereferencer();

        if (deref == null) {

            deref = DOMURIDereferencer.INSTANCE;

        }

        Data data = deref.dereference(this, context);

        // pass dereferenced data through Transforms

        try {

            for (int i = 0, size = transforms.size(); i < size; i++) {

                Transform transform = (Transform) transforms.get(i);

                data = ((DOMTransform) transform).transform(data, context);

            }

        } catch (Exception e) {

            throw new URIReferenceException(e);

        }

        return data;

    }

    public XMLStructure dereferenceAsXMLStructure(XMLCryptoContext context)

        throws URIReferenceException {

        try {

            ApacheData data = (ApacheData) dereference(context);

            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

            dbf.setNamespaceAware(true);

            DocumentBuilder db = dbf.newDocumentBuilder();

            Document doc = db.parse(new ByteArrayInputStream

                (data.getXMLSignatureInput().getBytes()));

            Element kiElem = doc.getDocumentElement();

            if (kiElem.getLocalName().equals("X509Data")) {

                return new DOMX509Data(kiElem);

            } else {

                return null; // unsupported

            }

        } catch (Exception e) {

            throw new URIReferenceException(e);

        }

    }

    public boolean equals(Object obj) {

        if (this == obj) {

            return true;

        }

        if (!(obj instanceof RetrievalMethod)) {

            return false;

        }

        RetrievalMethod orm = (RetrievalMethod) obj;

        boolean typesEqual = (type == null ? orm.getType() == null :

            type.equals(orm.getType()));

        return (uri.equals(orm.getURI()) &&

            transforms.equals(orm.getTransforms()) && typesEqual);

    }

}