/*
 * @(#)ComparisonFunction.java
 *
 * Copyright 2003-2004 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
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that this software is not designed or intended for use in
 * the design, construction, operation or maintenance of any nuclear facility.
 */

package org.wso2.balana.cond;

import org.wso2.balana.ctx.EvaluationCtx;

import org.wso2.balana.attr.AttributeValue;
import org.wso2.balana.attr.BooleanAttribute;
import org.wso2.balana.attr.DateAttribute;
import org.wso2.balana.attr.DateTimeAttribute;
import org.wso2.balana.attr.DoubleAttribute;
import org.wso2.balana.attr.IntegerAttribute;
import org.wso2.balana.attr.StringAttribute;
import org.wso2.balana.attr.TimeAttribute;

import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Set;

/**
 * A class that implements all of the standard comparison functions.
 * 
 * @since 1.0
 * @author Steve Hanna
 * @author Seth Proctor
 */
public class ComparisonFunction extends FunctionBase {

	/**
	 * Standard identifier for the integer-greater-than function.
	 */
	public static final String NAME_INTEGER_GREATER_THAN = FUNCTION_NS + "integer-greater-than";

	/**
	 * Standard identifier for the integer-greater-than-or-equal function.
	 */
	public static final String NAME_INTEGER_GREATER_THAN_OR_EQUAL = FUNCTION_NS
			+ "integer-greater-than-or-equal";

	/**
	 * Standard identifier for the integer-less-than function.
	 */
	public static final String NAME_INTEGER_LESS_THAN = FUNCTION_NS + "integer-less-than";

	/**
	 * Standard identifier for the integer-less-than-or-equal function.
	 */
	public static final String NAME_INTEGER_LESS_THAN_OR_EQUAL = FUNCTION_NS
			+ "integer-less-than-or-equal";

	/**
	 * Standard identifier for the double-greater-than function.
	 */
	public static final String NAME_DOUBLE_GREATER_THAN = FUNCTION_NS + "double-greater-than";

	/**
	 * Standard identifier for the double-greater-than-or-equal function.
	 */
	public static final String NAME_DOUBLE_GREATER_THAN_OR_EQUAL = FUNCTION_NS
			+ "double-greater-than-or-equal";

	/**
	 * Standard identifier for the double-less-than function.
	 */
	public static final String NAME_DOUBLE_LESS_THAN = FUNCTION_NS + "double-less-than";

	/**
	 * Standard identifier for the double-less-than-or-equal function.
	 */
	public static final String NAME_DOUBLE_LESS_THAN_OR_EQUAL = FUNCTION_NS
			+ "double-less-than-or-equal";

	/**
	 * Standard identifier for the string-greater-than function.
	 */
	public static final String NAME_STRING_GREATER_THAN = FUNCTION_NS + "string-greater-than";

	/**
	 * Standard identifier for the string-greater-than-or-equal function.
	 */
	public static final String NAME_STRING_GREATER_THAN_OR_EQUAL = FUNCTION_NS
			+ "string-greater-than-or-equal";

	/**
	 * Standard identifier for the string-less-than function.
	 */
	public static final String NAME_STRING_LESS_THAN = FUNCTION_NS + "string-less-than";

	/**
	 * Standard identifier for the string-less-than-or-equal function.
	 */
	public static final String NAME_STRING_LESS_THAN_OR_EQUAL = FUNCTION_NS
			+ "string-less-than-or-equal";

	/**
	 * Standard identifier for the time-greater-than function.
	 */
	public static final String NAME_TIME_GREATER_THAN = FUNCTION_NS + "time-greater-than";

	/**
	 * Standard identifier for the time-greater-than-or-equal function.
	 */
	public static final String NAME_TIME_GREATER_THAN_OR_EQUAL = FUNCTION_NS
			+ "time-greater-than-or-equal";

	/**
	 * Standard identifier for the time-less-than function.
	 */
	public static final String NAME_TIME_LESS_THAN = FUNCTION_NS + "time-less-than";

	/**
	 * Standard identifier for the time-less-than-or-equal function.
	 */
	public static final String NAME_TIME_LESS_THAN_OR_EQUAL = FUNCTION_NS
			+ "time-less-than-or-equal";

	/**
	 * Standard identifier for the dateTime-greater-than function.
	 */
	public static final String NAME_DATETIME_GREATER_THAN = FUNCTION_NS + "dateTime-greater-than";

	/**
	 * Standard identifier for the dateTime-greater-than-or-equal function.
	 */
	public static final String NAME_DATETIME_GREATER_THAN_OR_EQUAL = FUNCTION_NS
			+ "dateTime-greater-than-or-equal";

	/**
	 * Standard identifier for the dateTime-less-than function.
	 */
	public static final String NAME_DATETIME_LESS_THAN = FUNCTION_NS + "dateTime-less-than";

	/**
	 * Standard identifier for the dateTime-less-than-or-equal function.
	 */
	public static final String NAME_DATETIME_LESS_THAN_OR_EQUAL = FUNCTION_NS
			+ "dateTime-less-than-or-equal";

	/**
	 * Standard identifier for the date-greater-than function.
	 */
	public static final String NAME_DATE_GREATER_THAN = FUNCTION_NS + "date-greater-than";

	/**
	 * Standard identifier for the date-greater-than-or-equal function.
	 */
	public static final String NAME_DATE_GREATER_THAN_OR_EQUAL = FUNCTION_NS
			+ "date-greater-than-or-equal";

	/**
	 * Standard identifier for the date-less-than function.
	 */
	public static final String NAME_DATE_LESS_THAN = FUNCTION_NS + "date-less-than";

	/**
	 * Standard identifier for the date-less-than-or-equal function.
	 */
	public static final String NAME_DATE_LESS_THAN_OR_EQUAL = FUNCTION_NS
			+ "date-less-than-or-equal";

	// private identifiers for the supported functions
	private static final int ID_INTEGER_GREATER_THAN = 0;
	private static final int ID_INTEGER_GREATER_THAN_OR_EQUAL = 1;
	private static final int ID_INTEGER_LESS_THAN = 2;
	private static final int ID_INTEGER_LESS_THAN_OR_EQUAL = 3;
	private static final int ID_DOUBLE_GREATER_THAN = 4;
	private static final int ID_DOUBLE_GREATER_THAN_OR_EQUAL = 5;
	private static final int ID_DOUBLE_LESS_THAN = 6;
	private static final int ID_DOUBLE_LESS_THAN_OR_EQUAL = 7;
	private static final int ID_STRING_GREATER_THAN = 8;
	private static final int ID_STRING_GREATER_THAN_OR_EQUAL = 9;
	private static final int ID_STRING_LESS_THAN = 10;
	private static final int ID_STRING_LESS_THAN_OR_EQUAL = 11;
	private static final int ID_TIME_GREATER_THAN = 12;
	private static final int ID_TIME_GREATER_THAN_OR_EQUAL = 13;
	private static final int ID_TIME_LESS_THAN = 14;
	private static final int ID_TIME_LESS_THAN_OR_EQUAL = 15;
	private static final int ID_DATE_GREATER_THAN = 16;
	private static final int ID_DATE_GREATER_THAN_OR_EQUAL = 17;
	private static final int ID_DATE_LESS_THAN = 18;
	private static final int ID_DATE_LESS_THAN_OR_EQUAL = 19;
	private static final int ID_DATETIME_GREATER_THAN = 20;
	private static final int ID_DATETIME_GREATER_THAN_OR_EQUAL = 21;
	private static final int ID_DATETIME_LESS_THAN = 22;
	private static final int ID_DATETIME_LESS_THAN_OR_EQUAL = 23;

	// mappings from name to private identifier and argument datatype
	private static HashMap<String, Integer> idMap;
	private static HashMap<String, String> typeMap;

	/**
	 * Static initializer to setup the two maps.
	 */
	static {
		idMap = new HashMap<String, Integer>();

		idMap.put(NAME_INTEGER_GREATER_THAN, Integer.valueOf(ID_INTEGER_GREATER_THAN));
		idMap.put(NAME_INTEGER_GREATER_THAN_OR_EQUAL,
				Integer.valueOf(ID_INTEGER_GREATER_THAN_OR_EQUAL));
		idMap.put(NAME_INTEGER_LESS_THAN, Integer.valueOf(ID_INTEGER_LESS_THAN));
		idMap.put(NAME_INTEGER_LESS_THAN_OR_EQUAL, Integer.valueOf(ID_INTEGER_LESS_THAN_OR_EQUAL));
		idMap.put(NAME_DOUBLE_GREATER_THAN, Integer.valueOf(ID_DOUBLE_GREATER_THAN));
		idMap.put(NAME_DOUBLE_GREATER_THAN_OR_EQUAL,
				Integer.valueOf(ID_DOUBLE_GREATER_THAN_OR_EQUAL));
		idMap.put(NAME_DOUBLE_LESS_THAN, Integer.valueOf(ID_DOUBLE_LESS_THAN));
		idMap.put(NAME_DOUBLE_LESS_THAN_OR_EQUAL, Integer.valueOf(ID_DOUBLE_LESS_THAN_OR_EQUAL));
		idMap.put(NAME_STRING_GREATER_THAN, Integer.valueOf(ID_STRING_GREATER_THAN));
		idMap.put(NAME_STRING_GREATER_THAN_OR_EQUAL,
				Integer.valueOf(ID_STRING_GREATER_THAN_OR_EQUAL));
		idMap.put(NAME_STRING_LESS_THAN, Integer.valueOf(ID_STRING_LESS_THAN));
		idMap.put(NAME_STRING_LESS_THAN_OR_EQUAL, Integer.valueOf(ID_STRING_LESS_THAN_OR_EQUAL));
		idMap.put(NAME_TIME_GREATER_THAN, Integer.valueOf(ID_TIME_GREATER_THAN));
		idMap.put(NAME_TIME_GREATER_THAN_OR_EQUAL, Integer.valueOf(ID_TIME_GREATER_THAN_OR_EQUAL));
		idMap.put(NAME_TIME_LESS_THAN, Integer.valueOf(ID_TIME_LESS_THAN));
		idMap.put(NAME_TIME_LESS_THAN_OR_EQUAL, Integer.valueOf(ID_TIME_LESS_THAN_OR_EQUAL));
		idMap.put(NAME_DATE_GREATER_THAN, Integer.valueOf(ID_DATE_GREATER_THAN));
		idMap.put(NAME_DATE_GREATER_THAN_OR_EQUAL, Integer.valueOf(ID_DATE_GREATER_THAN_OR_EQUAL));
		idMap.put(NAME_DATE_LESS_THAN, Integer.valueOf(ID_DATE_LESS_THAN));
		idMap.put(NAME_DATE_LESS_THAN_OR_EQUAL, Integer.valueOf(ID_DATE_LESS_THAN_OR_EQUAL));
		idMap.put(NAME_DATETIME_GREATER_THAN, Integer.valueOf(ID_DATETIME_GREATER_THAN));
		idMap.put(NAME_DATETIME_GREATER_THAN_OR_EQUAL,
				Integer.valueOf(ID_DATETIME_GREATER_THAN_OR_EQUAL));
		idMap.put(NAME_DATETIME_LESS_THAN, Integer.valueOf(ID_DATETIME_LESS_THAN));
		idMap.put(NAME_DATETIME_LESS_THAN_OR_EQUAL, Integer.valueOf(ID_DATETIME_LESS_THAN_OR_EQUAL));

		typeMap = new HashMap<String, String>();

		typeMap.put(NAME_INTEGER_GREATER_THAN, IntegerAttribute.identifier);
		typeMap.put(NAME_INTEGER_GREATER_THAN_OR_EQUAL, IntegerAttribute.identifier);
		typeMap.put(NAME_INTEGER_LESS_THAN, IntegerAttribute.identifier);
		typeMap.put(NAME_INTEGER_LESS_THAN_OR_EQUAL, IntegerAttribute.identifier);
		typeMap.put(NAME_DOUBLE_GREATER_THAN, DoubleAttribute.identifier);
		typeMap.put(NAME_DOUBLE_GREATER_THAN_OR_EQUAL, DoubleAttribute.identifier);
		typeMap.put(NAME_DOUBLE_LESS_THAN, DoubleAttribute.identifier);
		typeMap.put(NAME_DOUBLE_LESS_THAN_OR_EQUAL, DoubleAttribute.identifier);
		typeMap.put(NAME_STRING_GREATER_THAN, StringAttribute.identifier);
		typeMap.put(NAME_STRING_GREATER_THAN_OR_EQUAL, StringAttribute.identifier);
		typeMap.put(NAME_STRING_LESS_THAN, StringAttribute.identifier);
		typeMap.put(NAME_STRING_LESS_THAN_OR_EQUAL, StringAttribute.identifier);
		typeMap.put(NAME_TIME_GREATER_THAN, TimeAttribute.identifier);
		typeMap.put(NAME_TIME_GREATER_THAN_OR_EQUAL, TimeAttribute.identifier);
		typeMap.put(NAME_TIME_LESS_THAN, TimeAttribute.identifier);
		typeMap.put(NAME_TIME_LESS_THAN_OR_EQUAL, TimeAttribute.identifier);
		typeMap.put(NAME_DATETIME_GREATER_THAN, DateTimeAttribute.identifier);
		typeMap.put(NAME_DATETIME_GREATER_THAN_OR_EQUAL, DateTimeAttribute.identifier);
		typeMap.put(NAME_DATETIME_LESS_THAN, DateTimeAttribute.identifier);
		typeMap.put(NAME_DATETIME_LESS_THAN_OR_EQUAL, DateTimeAttribute.identifier);
		typeMap.put(NAME_DATE_GREATER_THAN, DateAttribute.identifier);
		typeMap.put(NAME_DATE_GREATER_THAN_OR_EQUAL, DateAttribute.identifier);
		typeMap.put(NAME_DATE_LESS_THAN, DateAttribute.identifier);
		typeMap.put(NAME_DATE_LESS_THAN_OR_EQUAL, DateAttribute.identifier);
	};

	/**
	 * Creates a new <code>ComparisonFunction</code> object.
	 * 
	 * @param functionName the standard XACML name of the function to be handled by this object,
	 *            including the full namespace
	 * 
	 * @throws IllegalArgumentException if the function isn't known
	 */
	public ComparisonFunction(String functionName) {
		super(functionName, getId(functionName), getArgumentType(functionName), false, 2,
				BooleanAttribute.identifier, false);
	}

	/**
	 * Private helper that returns the internal identifier used for the given standard function.
	 */
	private static int getId(String functionName) {
		Integer i = (Integer) (idMap.get(functionName));

		if (i == null)
			throw new IllegalArgumentException("unknown comparison function " + functionName);

		return i.intValue();
	}

	/**
	 * Private helper that returns the type used for the given standard function. Note that this
	 * doesn't check on the return value since the method always is called after getId, so we assume
	 * that the function is present.
	 */
	private static String getArgumentType(String functionName) {
		return (String) (typeMap.get(functionName));
	}

	/**
	 * Returns a <code>Set</code> containing all the function identifiers supported by this class.
	 * 
	 * @return a <code>Set</code> of <code>String</code>s
	 */
	public static Set getSupportedIdentifiers() {
		return Collections.unmodifiableSet(idMap.keySet());
	}

	/**
	 * Evaluate the function, using the specified parameters.
	 * 
	 * @param inputs a <code>List</code> of <code>Evaluatable</code> objects representing the
	 *            arguments passed to the function
	 * @param context an <code>EvaluationCtx</code> so that the <code>Evaluatable</code> objects can
	 *            be evaluated
	 * @return an <code>EvaluationResult</code> representing the function's result
	 */
	public EvaluationResult evaluate(List inputs, EvaluationCtx context) {
		// Evaluate the arguments
		AttributeValue[] argValues = new AttributeValue[inputs.size()];
		EvaluationResult result = evalArgs(inputs, context, argValues);
		if (result != null)
			return result;

		// Now that we have real values, perform the comparison operation

		boolean boolResult = false;

		switch (getFunctionId()) {

		case ID_INTEGER_GREATER_THAN: {
			long arg0 = ((IntegerAttribute) (argValues[0])).getValue();
			long arg1 = ((IntegerAttribute) (argValues[1])).getValue();

			boolResult = (arg0 > arg1);

			break;
		}

		case ID_INTEGER_GREATER_THAN_OR_EQUAL: {
			long arg0 = ((IntegerAttribute) (argValues[0])).getValue();
			long arg1 = ((IntegerAttribute) (argValues[1])).getValue();

			boolResult = (arg0 >= arg1);

			break;
		}

		case ID_INTEGER_LESS_THAN: {
			long arg0 = ((IntegerAttribute) (argValues[0])).getValue();
			long arg1 = ((IntegerAttribute) (argValues[1])).getValue();

			boolResult = (arg0 < arg1);

			break;
		}

		case ID_INTEGER_LESS_THAN_OR_EQUAL: {
			long arg0 = ((IntegerAttribute) (argValues[0])).getValue();
			long arg1 = ((IntegerAttribute) (argValues[1])).getValue();

			boolResult = (arg0 <= arg1);

			break;
		}

		case ID_DOUBLE_GREATER_THAN: {
			double arg0 = ((DoubleAttribute) (argValues[0])).getValue();
			double arg1 = ((DoubleAttribute) (argValues[1])).getValue();

			boolResult = (doubleCompare(arg0, arg1) > 0);

			break;
		}

		case ID_DOUBLE_GREATER_THAN_OR_EQUAL: {
			double arg0 = ((DoubleAttribute) (argValues[0])).getValue();
			double arg1 = ((DoubleAttribute) (argValues[1])).getValue();

			boolResult = (doubleCompare(arg0, arg1) >= 0);

			break;
		}

		case ID_DOUBLE_LESS_THAN: {
			double arg0 = ((DoubleAttribute) (argValues[0])).getValue();
			double arg1 = ((DoubleAttribute) (argValues[1])).getValue();

			boolResult = (doubleCompare(arg0, arg1) < 0);

			break;
		}

		case ID_DOUBLE_LESS_THAN_OR_EQUAL: {
			double arg0 = ((DoubleAttribute) (argValues[0])).getValue();
			double arg1 = ((DoubleAttribute) (argValues[1])).getValue();

			boolResult = (doubleCompare(arg0, arg1) <= 0);

			break;
		}

		case ID_STRING_GREATER_THAN: {
			String arg0 = ((StringAttribute) (argValues[0])).getValue();
			String arg1 = ((StringAttribute) (argValues[1])).getValue();

			boolResult = (arg0.compareTo(arg1) > 0);

			break;
		}

		case ID_STRING_GREATER_THAN_OR_EQUAL: {
			String arg0 = ((StringAttribute) (argValues[0])).getValue();
			String arg1 = ((StringAttribute) (argValues[1])).getValue();

			boolResult = (arg0.compareTo(arg1) >= 0);

			break;
		}

		case ID_STRING_LESS_THAN: {
			String arg0 = ((StringAttribute) (argValues[0])).getValue();
			String arg1 = ((StringAttribute) (argValues[1])).getValue();

			boolResult = (arg0.compareTo(arg1) < 0);

			break;
		}

		case ID_STRING_LESS_THAN_OR_EQUAL: {
			String arg0 = ((StringAttribute) (argValues[0])).getValue();
			String arg1 = ((StringAttribute) (argValues[1])).getValue();

			boolResult = (arg0.compareTo(arg1) <= 0);

			break;
		}

		case ID_TIME_GREATER_THAN: {
			TimeAttribute arg0 = (TimeAttribute) (argValues[0]);
			TimeAttribute arg1 = (TimeAttribute) (argValues[1]);

			boolResult = (dateCompare(arg0.getValue(), arg0.getNanoseconds(), arg1.getValue(),
					arg1.getNanoseconds()) > 0);

			break;
		}

		case ID_TIME_GREATER_THAN_OR_EQUAL: {
			TimeAttribute arg0 = (TimeAttribute) (argValues[0]);
			TimeAttribute arg1 = (TimeAttribute) (argValues[1]);

			boolResult = (dateCompare(arg0.getValue(), arg0.getNanoseconds(), arg1.getValue(),
					arg1.getNanoseconds()) >= 0);

			break;
		}

		case ID_TIME_LESS_THAN: {
			TimeAttribute arg0 = (TimeAttribute) (argValues[0]);
			TimeAttribute arg1 = (TimeAttribute) (argValues[1]);

			boolResult = (dateCompare(arg0.getValue(), arg0.getNanoseconds(), arg1.getValue(),
					arg1.getNanoseconds()) < 0);

			break;
		}

		case ID_TIME_LESS_THAN_OR_EQUAL: {
			TimeAttribute arg0 = (TimeAttribute) (argValues[0]);
			TimeAttribute arg1 = (TimeAttribute) (argValues[1]);

			boolResult = (dateCompare(arg0.getValue(), arg0.getNanoseconds(), arg1.getValue(),
					arg1.getNanoseconds()) <= 0);

			break;
		}

		case ID_DATETIME_GREATER_THAN: {
			DateTimeAttribute arg0 = (DateTimeAttribute) (argValues[0]);
			DateTimeAttribute arg1 = (DateTimeAttribute) (argValues[1]);

			boolResult = (dateCompare(arg0.getValue(), arg0.getNanoseconds(), arg1.getValue(),
					arg1.getNanoseconds()) > 0);

			break;
		}

		case ID_DATETIME_GREATER_THAN_OR_EQUAL: {
			DateTimeAttribute arg0 = (DateTimeAttribute) (argValues[0]);
			DateTimeAttribute arg1 = (DateTimeAttribute) (argValues[1]);

			boolResult = (dateCompare(arg0.getValue(), arg0.getNanoseconds(), arg1.getValue(),
					arg1.getNanoseconds()) >= 0);

			break;
		}

		case ID_DATETIME_LESS_THAN: {
			DateTimeAttribute arg0 = (DateTimeAttribute) (argValues[0]);
			DateTimeAttribute arg1 = (DateTimeAttribute) (argValues[1]);

			boolResult = (dateCompare(arg0.getValue(), arg0.getNanoseconds(), arg1.getValue(),
					arg1.getNanoseconds()) < 0);

			break;
		}

		case ID_DATETIME_LESS_THAN_OR_EQUAL: {
			DateTimeAttribute arg0 = (DateTimeAttribute) (argValues[0]);
			DateTimeAttribute arg1 = (DateTimeAttribute) (argValues[1]);

			boolResult = (dateCompare(arg0.getValue(), arg0.getNanoseconds(), arg1.getValue(),
					arg1.getNanoseconds()) <= 0);

			break;
		}

		case ID_DATE_GREATER_THAN: {
			Date arg0 = ((DateAttribute) (argValues[0])).getValue();
			Date arg1 = ((DateAttribute) (argValues[1])).getValue();

			boolResult = (arg0.compareTo(arg1) > 0);

			break;
		}

		case ID_DATE_GREATER_THAN_OR_EQUAL: {
			Date arg0 = ((DateAttribute) (argValues[0])).getValue();
			Date arg1 = ((DateAttribute) (argValues[1])).getValue();

			boolResult = (arg0.compareTo(arg1) >= 0);

			break;
		}

		case ID_DATE_LESS_THAN: {
			Date arg0 = ((DateAttribute) (argValues[0])).getValue();
			Date arg1 = ((DateAttribute) (argValues[1])).getValue();

			boolResult = (arg0.compareTo(arg1) < 0);

			break;
		}

		case ID_DATE_LESS_THAN_OR_EQUAL: {
			Date arg0 = ((DateAttribute) (argValues[0])).getValue();
			Date arg1 = ((DateAttribute) (argValues[1])).getValue();

			boolResult = (arg0.compareTo(arg1) <= 0);

			break;
		}

		}

		// Return the result as a BooleanAttribute.
		return EvaluationResult.getInstance(boolResult);
	}

	/**
	 * Helper function that does a comparison of the two doubles using the rules of XMLSchema. Like
	 * all compare methods, this returns 0 if they're equal, a positive value if d1 > d2, and a
	 * negative value if d1 < d2.
	 */
	private int doubleCompare(double d1, double d2) {
		// see if the numbers equal each other
		if (d1 == d2) {
			// these are not NaNs, and therefore we just need to check that
			// that they're not zeros, which may have different signs
			if (d1 != 0)
				return 0;

			// they're both zeros, so we compare strings to figure out
			// the significance of any signs
			return Double.toString(d1).compareTo(Double.toString(d2));
		}

		// see if d1 is NaN
		if (Double.isNaN(d1)) {
			// d1 is NaN, so see if d2 is as well
			if (Double.isNaN(d2)) {
				// they're both NaNs, so they're equal
				return 0;
			} else {
				// d1 is always bigger than d2 since it's a NaN
				return 1;
			}
		}

		// see if d2 is NaN
		if (Double.isNaN(d2)) {
			// d2 is a NaN, though d1 isn't, so d2 is always bigger
			return -1;
		}

		// if we got here then neither is a NaN, and the numbers aren't
		// equal...given those facts, basic comparison works the same in
		// java as it's defined in XMLSchema, so now we can do the simple
		// comparison and return whatever we find
		return ((d1 > d2) ? 1 : -1);
	}

	/**
	 * Helper function to compare two Date objects and their associated nanosecond values. Like all
	 * compare methods, this returns 0 if they're equal, a positive value if d1 > d2, and a negative
	 * value if d1 < d2.
	 */
	private int dateCompare(Date d1, int n1, Date d2, int n2) {
		int compareResult = d1.compareTo(d2);

		// we only worry about the nanosecond values if the Dates are equal
		if (compareResult != 0)
			return compareResult;

		// see if there's any difference
		if (n1 == n2)
			return 0;

		// there is some difference in the nanoseconds, and that's how
		// we'll determine the comparison
		return ((n1 > n2) ? 1 : -1);
	}

}
