/*
 * @(#)$Id: DoubleType.java,v 1.18 2001/11/27 01:54:52 kk122374 Exp $
 *
 * Copyright 2001 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * This software is the proprietary information of Sun Microsystems, Inc.  
 * Use is subject to license terms.
 * 
 */
package com.sun.msv.datatype.xsd;

import org.relaxng.datatype.ValidationContext;
import com.sun.msv.datatype.SerializationContext;

/**
 * "double" type.
 * 
 * type of the value object is <code>java.lang.Double</code>.
 * See http://www.w3.org/TR/xmlschema-2/#double for the spec
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class DoubleType extends FloatingNumberType {
	
	public static final DoubleType theInstance = new DoubleType();
	private DoubleType() { super("double"); }
	
	final public XSDatatype getBaseType() {
		return SimpleURType.theInstance;
	}
	
	public Object _createValue( String lexicalValue, ValidationContext context ) {
        return load(lexicalValue);
    }
    
    public static Double load( String lexicalValue ) {
		// TODO : probably the same problems exist as in the case of float
		try {
			if(lexicalValue.equals("NaN"))	return new Double(Double.NaN);
			if(lexicalValue.equals("INF"))	return new Double(Double.POSITIVE_INFINITY);
			if(lexicalValue.equals("-INF"))	return new Double(Double.NEGATIVE_INFINITY);
			
			if(lexicalValue.length()==0
			|| !isDigitOrPeriodOrSign(lexicalValue.charAt(0))
			|| !isDigitOrPeriodOrSign(lexicalValue.charAt(lexicalValue.length()-1)) )
				return null;
			
			
			// these screening process is necessary due to the wobble of Float.valueOf method
			return Double.valueOf(lexicalValue);
		} catch( NumberFormatException e ) {
			return null;
		}
	}
	
	public String convertToLexicalValue( Object value, SerializationContext context ) {
		if(!(value instanceof Double ))
			throw new IllegalArgumentException();
		
        return save((Double)value);
    }
    
    public static String save( Double value ) {
		double v = value.doubleValue();
		if( v==Double.NaN )					return "NaN";
		if( v==Double.POSITIVE_INFINITY )	return "INF";
		if( v==Double.NEGATIVE_INFINITY )	return "-INF";
		return value.toString();
	}
	public Class getJavaObjectType() {
		return Double.class;
	}
}