/*
 * @(#)$Id: LengthFacet.java,v 1.21 2002/06/24 19:57:28 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 java.util.Hashtable;
import org.relaxng.datatype.DatatypeException;
import org.relaxng.datatype.ValidationContext;

/**
 * "length", "minLength", and "maxLength" facet validator.
 * 
 * this class also detects inconsistent facet setting
 * (for example, minLength=100 and maxLength=0)
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class LengthFacet extends DataTypeWithValueConstraintFacet {
	public final int length;
	
	protected LengthFacet( String nsUri, String typeName, XSDatatypeImpl baseType, TypeIncubator facets )
		throws DatatypeException {
		super(nsUri,typeName,baseType,FACET_LENGTH,facets);
	
		length = facets.getNonNegativeInteger(FACET_LENGTH);
		
		// loosened facet check
		DataTypeWithFacet o = baseType.getFacetObject(FACET_LENGTH);
		if(o!=null && ((LengthFacet)o).length != this.length )
			throw new DatatypeException(
				localize(ERR_LOOSENED_FACET, FACET_LENGTH, o.displayName() ) );
		
		// consistency with minLength/maxLength is checked in XSDatatypeImpl.derive method.
	}
	
	public Object _createValue( String content, ValidationContext context ) {
		Object o = baseType._createValue(content,context);
		if(o==null || ((Discrete)concreteType).countLength(o)!=length)	return null;
		return o;
	}
	
	protected void diagnoseByFacet(String content, ValidationContext context) throws DatatypeException {
		Object o = concreteType._createValue(content,context);
		// base type must have accepted this lexical value, otherwise 
		// this method is never called.
		if(o==null)	throw new IllegalStateException();	// assertion
		
		int cnt = ((Discrete)concreteType).countLength(o);
		if(cnt!=length)
			throw new DatatypeException( DatatypeException.UNKNOWN,
				localize(ERR_LENGTH, new Integer(cnt), new Integer(length)) );
	}
}