/**
 * 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.transforms;

import java.io.IOException;
import java.io.OutputStream;

import javax.xml.parsers.ParserConfigurationException;

import org.apache.xml.security.c14n.CanonicalizationException;
import org.apache.xml.security.c14n.InvalidCanonicalizerException;
import org.apache.xml.security.signature.XMLSignatureInput;
import org.w3c.dom.Element;
import org.xml.sax.SAXException;

/**
 * Base class which all Transform algorithms extend. The common methods that
 * have to be overridden are the
 * {@link #enginePerformTransform(XMLSignatureInput, OutputStream, Element, String, boolean)} method.
 *
 * Extensions of this class must be thread-safe.
 */
public abstract class TransformSpi {


    /**
     * The mega method which MUST be implemented by the Transformation Algorithm.
     *
     * @param input {@link XMLSignatureInput} as the input of transformation
     * @param os where to output this transformation.
     * @param transformElement the Transform element
     * @param baseURI The baseURI
     * @param secureValidation Whether secure validation is enabled
     * @return {@link XMLSignatureInput} as the result of transformation
     * @throws CanonicalizationException
     * @throws IOException
     * @throws InvalidCanonicalizerException
     * @throws ParserConfigurationException
     * @throws SAXException
     * @throws TransformationException
     */
    protected abstract XMLSignatureInput enginePerformTransform(
        XMLSignatureInput input, OutputStream os, Element transformElement,
        String baseURI, boolean secureValidation
    ) throws IOException, CanonicalizationException, InvalidCanonicalizerException,
        TransformationException, ParserConfigurationException, SAXException;

    /**
     * Returns the URI representation of <code>Transformation algorithm</code>
     *
     * @return the URI representation of <code>Transformation algorithm</code>
     */
    protected abstract String engineGetURI();
}
