/**
 * 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.
 */
/*
 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
 */
/*
 * $Id: DOMCanonicalizationMethod.java 1333415 2012-05-03 12:03:51Z coheigea $
 */
package org.apache.jcp.xml.dsig.internal.dom;

import org.w3c.dom.Element;

import javax.xml.crypto.Data;
import javax.xml.crypto.MarshalException;
import javax.xml.crypto.XMLCryptoContext;
import javax.xml.crypto.dsig.CanonicalizationMethod;
import javax.xml.crypto.dsig.TransformException;
import javax.xml.crypto.dsig.TransformService;
import java.io.OutputStream;
import java.security.InvalidAlgorithmParameterException;
import java.security.Provider;

/**
 * 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,
                                   Provider provider)
    throws MarshalException {
    super(cmElem, context, provider);
  }

  /**
   * 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 TransformException   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);
  }

  @Override
  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()));
  }

  @Override
  public int hashCode() {
    assert false : "hashCode not designed";
    return 42; // any arbitrary constant will do
  }
}