/*
 * @(#)RuleCombinerElement.java
 *
 * Copyright 2005 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistribution of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 * 
 *   2. Redistribution in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
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 */

package com.sun.xacml.combine;

import java.io.OutputStream;
import java.io.PrintStream;
import java.util.List;

import com.sun.xacml.Indenter;
import com.sun.xacml.Rule;

/**
 * Specific version of <code>CombinerElement</code> used for rule combining.
 * 
 * @since 2.0
 * @author Seth Proctor
 * 
 *         Adding generic type support by Christian Mueller (geotools)
 */
public class RuleCombinerElement extends CombinerElement {

    /**
     * Constructor that only takes a <code>Rule</code. No parameters are
     * associated with this <code>Rule</code> when combining.
     * 
     * @param rule
     *            a <code>Rule</code> to use in combining
     */
    public RuleCombinerElement(Rule rule) {
        super(rule);
    }

    /**
     * Constructor that takes both the <code>Rule</code> to combine and its associated combiner
     * parameters.
     * 
     * @param rule
     *            a <code>Rule</code> to use in combining
     * @param parameters
     *            a (possibly empty) non-null <code>List</code> of
     *            <code>CombinerParameter<code>s provided for general
     *                   use (for all pre-2.0 policies this must be empty)
     */
    public RuleCombinerElement(Rule rule, List<CombinerParameter> parameters) {
        super(rule, parameters);
    }

    /**
     * Returns the <code>Rule</code> in this element.
     * 
     * @return the element's <code>Rule</code>
     */
    public Rule getRule() {
        return (Rule) (getElement());
    }

    /**
     * Encodes this element's <code>Rule</code> and parameters into their XML representation and
     * writes this encoding to the given <code>OutputStream</code> with indentation.
     * 
     * @param output
     *            a stream into which the XML-encoded data is written
     * @param indenter
     *            an object that creates indentation strings
     */
    public void encode(OutputStream output, Indenter indenter) {

        if (getParameters().size() > 0) {
            PrintStream out = new PrintStream(output);
            String indent = indenter.makeString();

            out
                    .println(indent + "<RuleCombinerParameters RuleIdRef=\"" + getRule().getId()
                            + "\">");
            indenter.in();

            for (CombinerParameter param : getParameters())
                param.encode(output, indenter);

            out.println(indent + "</RuleCombinerParameters>");
            indenter.out();
        }

        getRule().encode(output, indenter);
    }

}