/*
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 */
/*
 * $Id: DOMCanonicalizationMethod.java,v 1.25 2005/05/10 18:15:31 mullan Exp $
 */
package org.jcp.xml.dsig.internal.dom;

import java.io.OutputStream;
import java.security.InvalidAlgorithmParameterException;

import org.w3c.dom.Element;

import javax.xml.crypto.*;
import javax.xml.crypto.dsig.*;

/**
 * DOM-based abstract implementation of CanonicalizationMethod.
 *
 * @author Sean Mullan
 */
public class DOMCanonicalizationMethod extends DOMTransform 
    implements CanonicalizationMethod {

    /**
     * Creates a <code>DOMCanonicalizationMethod</code>.
     *
     * @param spi TransformService
     */
    public DOMCanonicalizationMethod(TransformService spi)
	throws InvalidAlgorithmParameterException {
	super(spi);
    }

    /**
     * Creates a <code>DOMCanonicalizationMethod</code> from an element. This 
     * ctor invokes the abstract {@link #unmarshalParams unmarshalParams} 
     * method to unmarshal any algorithm-specific input parameters.
     *
     * @param cmElem a CanonicalizationMethod element
     */
    public DOMCanonicalizationMethod(Element cmElem, XMLCryptoContext context) 
	throws MarshalException{
	super(cmElem, context);
    }

    /**
     * Canonicalizes the specified data using the underlying canonicalization
     * algorithm. This is a convenience method that is equivalent to invoking
     * the {@link #transform transform} method.
     *
     * @param data the data to be canonicalized
     * @param xc the <code>XMLCryptoContext</code> containing
     *     additional context (may be <code>null</code> if not applicable)
     * @return the canonicalized data
     * @throws NullPointerException if <code>data</code> is <code>null</code>
     * @throws XMLSignatureException if an unexpected error occurs while
     *    canonicalizing the data
     */
    public Data canonicalize(Data data, XMLCryptoContext xc) 
	throws TransformException {
	return transform(data, xc);
    }

    public Data canonicalize(Data data, XMLCryptoContext xc, OutputStream os) 
	throws TransformException {
	return transform(data, xc, os);
    }

    public boolean equals(Object o) {
	if (this == o) {
            return true;
	}

        if (!(o instanceof CanonicalizationMethod)) {
            return false;
	}
        CanonicalizationMethod ocm = (CanonicalizationMethod) o;

	return (getAlgorithm().equals(ocm.getAlgorithm()) && 
	    DOMUtils.paramsEqual(getParameterSpec(), ocm.getParameterSpec()));
    }
}