/*
 * Copyright  1999-2004 The Apache Software Foundation.
 *
 *  Licensed 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.xml.security.keys.content;

import java.security.PublicKey;

import org.apache.xml.security.exceptions.XMLSecurityException;
import org.apache.xml.security.keys.content.keyvalues.DSAKeyValue;
import org.apache.xml.security.keys.content.keyvalues.RSAKeyValue;
import org.apache.xml.security.utils.Constants;
import org.apache.xml.security.utils.SignatureElementProxy;
import org.apache.xml.security.utils.XMLUtils;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

/**
 * The KeyValue element contains a single public key that may be useful in
 * validating the signature. Structured formats for defining DSA (REQUIRED)
 * and RSA (RECOMMENDED) public keys are defined in Signature Algorithms
 * (section 6.4). The KeyValue element may include externally defined public
 * keys values represented as PCDATA or element types from an external 
 * namespace.
 *
 * @author $Author: mullan $
 */
public class KeyValue extends SignatureElementProxy implements KeyInfoContent {

    /**
     * Constructor KeyValue
     *
     * @param doc
     * @param dsaKeyValue
     */
    public KeyValue(Document doc, DSAKeyValue dsaKeyValue) {

        super(doc);

        XMLUtils.addReturnToElement(this._constructionElement);
        this._constructionElement.appendChild(dsaKeyValue.getElement());
        XMLUtils.addReturnToElement(this._constructionElement);
    }

    /**
     * Constructor KeyValue
     *
     * @param doc
     * @param rsaKeyValue
     */
    public KeyValue(Document doc, RSAKeyValue rsaKeyValue) {

        super(doc);

        XMLUtils.addReturnToElement(this._constructionElement);
        this._constructionElement.appendChild(rsaKeyValue.getElement());
        XMLUtils.addReturnToElement(this._constructionElement);
    }

    /**
     * Constructor KeyValue
     *
     * @param doc
     * @param unknownKeyValue
     */
    public KeyValue(Document doc, Element unknownKeyValue) {

        super(doc);

        XMLUtils.addReturnToElement(this._constructionElement);
        this._constructionElement.appendChild(unknownKeyValue);
        XMLUtils.addReturnToElement(this._constructionElement);
    }

    /**
     * Constructor KeyValue
     *
     * @param doc
     * @param pk
     */
    public KeyValue(Document doc, PublicKey pk) {

        super(doc);

        XMLUtils.addReturnToElement(this._constructionElement);

        if (pk instanceof java.security.interfaces.DSAPublicKey) {
            DSAKeyValue dsa = new DSAKeyValue(this._doc, pk);

            this._constructionElement.appendChild(dsa.getElement());
            XMLUtils.addReturnToElement(this._constructionElement);
        } else if (pk instanceof java.security.interfaces.RSAPublicKey) {
            RSAKeyValue rsa = new RSAKeyValue(this._doc, pk);

            this._constructionElement.appendChild(rsa.getElement());
            XMLUtils.addReturnToElement(this._constructionElement);
        }
    }

    /**
     * Constructor KeyValue
     *
     * @param element
     * @param BaseURI
     * @throws XMLSecurityException
     */
    public KeyValue(Element element, String BaseURI)
           throws XMLSecurityException {
        super(element, BaseURI);
    }

    /**
     * Method getPublicKey
     *
     * @return the public key
     * @throws XMLSecurityException
     */
    public PublicKey getPublicKey() throws XMLSecurityException {

	Element rsa = XMLUtils.selectDsNode
	    (this._constructionElement.getFirstChild(),
	     Constants._TAG_RSAKEYVALUE,0);
         
	if (rsa != null) {
            RSAKeyValue kv = new RSAKeyValue(rsa, this._baseURI);
            return kv.getPublicKey();
	}

	Element dsa = XMLUtils.selectDsNode
	    (this._constructionElement.getFirstChild(),
	     Constants._TAG_DSAKEYVALUE,0);

	if (dsa != null) {
            DSAKeyValue kv = new DSAKeyValue(dsa, this._baseURI);
            return kv.getPublicKey();
	}

	return null;
    }

    /** @inheritDoc */
    public String getBaseLocalName() {
        return Constants._TAG_KEYVALUE;
    }
}