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*/

package com.google.refine.sorting;

import java.util.Calendar;
import java.util.Date;

import com.google.refine.expr.EvalError;
import com.google.refine.expr.ExpressionUtils;

public class NumberCriterion extends Criterion {

    final static protected EvalError s_error = new EvalError("Not a number");

    @Override
    public KeyMaker createKeyMaker() {
        return new KeyMaker() {
            @Override
            protected Object makeKey(Object value) {
                if (ExpressionUtils.isNonBlankData(value)) {
                    if (value instanceof Number) {
                        return value;
                    } else if (value instanceof Boolean) {
                        return ((Boolean) value).booleanValue() ? 1 : 0;
                    } else if (value instanceof Date) {
                        return ((Date) value).getTime();
                    } else if (value instanceof Calendar) {
                        return ((Calendar) value).getTime().getTime();
                    } else if (value instanceof String) {
                        try {
                            double d = Double.parseDouble((String) value);
                            if (!Double.isNaN(d)) {
                                return d;
                            }
                        } catch (NumberFormatException e) {
                            // fall through
                        }
                    }
                    return s_error;
                }
                return value;
            }

            @Override
            public int compareKeys(Object key1, Object key2) {
                double d1 = ((Number) key1).doubleValue();
                double d2 = ((Number) key2).doubleValue();
                return d1 < d2 ? -1 : (d1 > d2 ? 1 : 0);
            }
        };
    }
}
