package net.sf.saxon.functions;

import net.sf.saxon.expr.XPathContext;
import net.sf.saxon.om.Item;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.value.AtomicValue;
import net.sf.saxon.value.NumericValue;

/**
* This class supports the ceiling(), floor(), round(), and round-to-half-even() functions,
 * and also the abs() function
*/

public final class Rounding extends SystemFunction {

    public static final int FLOOR = 0;
    public static final int CEILING = 1;
    public static final int ROUND = 2;
    public static final int HALF_EVEN = 3;
    public static final int ABS = 4;

    /**
    * Evaluate the function
    */

    /*@Nullable*/ public Item evaluateItem(XPathContext context) throws XPathException {

        AtomicValue val0 = (AtomicValue)argument[0].evaluateItem(context);
        if (val0 == null) {
            return null;
        }
        NumericValue val = (NumericValue)val0;

        switch (operation) {
            case FLOOR:
                return val.floor();
            case CEILING:
                return val.ceiling();
            case ROUND:
            	 int scaleRnd = 0;
                 if (argument.length==2) {
                	 NumericValue scaleVal = (NumericValue)argument[1].evaluateItem(context);
                     scaleRnd = (int)scaleVal.longValue();
                 }
                return val.round(scaleRnd);
            case HALF_EVEN:
                int scale = 0;
                if (argument.length==2) {
                	NumericValue scaleVal = (NumericValue)argument[1].evaluateItem(context);
                    scale = (int)scaleVal.longValue();
                }
                return val.roundHalfToEven(scale);
            case ABS:
                return val.abs();
            default:
                throw new UnsupportedOperationException("Unknown rounding function");
        }
    }

    /**
     * Determine the cardinality of the function.
     */

    public int computeCardinality() {
        return argument[0].getCardinality();
    }
}

//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (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.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file
//
// The Initial Developer of the Original Code is Saxonica Limited.
// Portions created by ___ are Copyright (C) ___. All rights reserved.
//
// Contributor(s):
//