/**
 * 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 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.ECKeyValue;
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.
 */
public class KeyValue extends SignatureElementProxy implements KeyInfoContent {

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

        addReturnToSelf();
        appendSelf(dsaKeyValue);
        addReturnToSelf();
    }

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

        addReturnToSelf();
        appendSelf(rsaKeyValue);
        addReturnToSelf();
    }

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

        addReturnToSelf();
        appendSelf(unknownKeyValue);
        addReturnToSelf();
    }

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

        addReturnToSelf();

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

            appendSelf(dsa);
            addReturnToSelf();
        } else if (pk instanceof java.security.interfaces.RSAPublicKey) {
            RSAKeyValue rsa = new RSAKeyValue(getDocument(), pk);

            appendSelf(rsa);
            addReturnToSelf();
        } else if (pk instanceof java.security.interfaces.ECPublicKey) {
            ECKeyValue ec = new ECKeyValue(getDocument(), pk);

            appendSelf(ec);
            addReturnToSelf();
        } else {
            String error = "The given PublicKey type " + pk + " is not supported. Only DSAPublicKey and "
                + "RSAPublicKey and ECPublicKey types are currently supported";
            throw new IllegalArgumentException(error);
        }
    }

    /**
     * Verifies that the XML KeyValue encoding is supported for the given key type. If the
     * encoding is supported, it returns true else false.
     *
     * @return true if the public key has a KeyValue encoding, false otherwise.
     */
    public static boolean isSupportedKeyType(PublicKey publicKey) {

        return publicKey instanceof java.security.interfaces.DSAPublicKey
                || publicKey instanceof java.security.interfaces.RSAPublicKey
                || publicKey instanceof java.security.interfaces.ECPublicKey;

    }

    /**
     * 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(
                getFirstChild(), Constants._TAG_RSAKEYVALUE, 0);

        if (rsa != null) {
            RSAKeyValue kv = new RSAKeyValue(rsa, this.baseURI);
            return kv.getPublicKey();
        }

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

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

        return null;
    }

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