/*
 * @(#)$Id: InlineElementState.java,v 1.12 2002/06/24 19:57:59 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.reader.relax.core;

import com.sun.msv.datatype.xsd.XSDatatype;
//import com.sun.msv.datatype.xsd.TypeIncubator;
import com.sun.msv.grammar.Expression;
import com.sun.msv.grammar.SimpleNameClass;
import com.sun.msv.grammar.relax.ElementRule;
import com.sun.msv.grammar.relax.TagClause;
import com.sun.msv.grammar.relax.AttPoolClause;
import com.sun.msv.reader.State;
import com.sun.msv.reader.ExpressionState;
import com.sun.msv.reader.datatype.xsd.FacetStateParent;
import com.sun.msv.reader.datatype.xsd.XSDatatypeExp;
import com.sun.msv.reader.datatype.xsd.XSTypeIncubator;
import com.sun.msv.util.StartTagInfo;
import org.relaxng.datatype.DatatypeException;

/**
 * parses <element> element.
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class InlineElementState extends ExpressionState implements FacetStateParent {
	
	/** this field is set to null if this element has label attribute. */
	protected XSTypeIncubator incubator;
	
	public XSTypeIncubator getIncubator() { return incubator; }
	
	protected State createChildState( StartTagInfo tag ) {
		if( incubator!=null )
			return ((RELAXCoreReader)reader).createFacetState(this,tag);	// facets
		else
			return null;	// nothing is allowed when @label is used.
	}
	
	protected void startSelf() {
		super.startSelf();
        
		final RELAXCoreReader reader = (RELAXCoreReader)this.reader;
		String type		= startTag.getAttribute("type");
		String label	= startTag.getAttribute("label");
		
		if( type!=null && label!=null )
			reader.reportError( reader.ERR_CONFLICTING_ATTRIBUTES, "type", "label" );
			// recover by ignoring one attribute.
		
		if( type==null && label==null ) {
			reader.reportError( reader.ERR_MISSING_ATTRIBUTE_2, "element", "type", "label" );
			type="string";
		}
		
		if( label!=null ) {
			incubator = null;
		} else {
			incubator = reader.resolveXSDatatype(type).createIncubator();
		}
	}
	
	protected Expression makeExpression() {
		try {
			final RELAXCoreReader reader = (RELAXCoreReader)this.reader;
			final String name		= startTag.getAttribute("name");
			
			if( name==null ) {
				reader.reportError( reader.ERR_MISSING_ATTRIBUTE, "element","name" );
				// recover by ignoring this element.
				return Expression.nullSet;
			}
			
			Expression contentModel;

			if( incubator!=null ) {
				contentModel = incubator.derive(null,null);
			} else {
				// @label is used
				String label = startTag.getAttribute("label");
				if(label==null)	throw new Error();
				
				contentModel = reader.module.hedgeRules.getOrCreate(label);
				reader.backwardReference.memorizeLink(contentModel);
			}
			
			TagClause c = new TagClause();
			c.nameClass = new SimpleNameClass( ((RELAXCoreReader)reader).module.targetNamespace, name );
			
			final String role = startTag.getAttribute("role");
			if( role==null )	c.exp = Expression.epsilon;	// no attribute
			else {
				// role attribute
				AttPoolClause att = reader.module.attPools.getOrCreate(role);
				c.exp = att;
				reader.backwardReference.memorizeLink(att);
			}
			
			// create anonymous ElementRule. this rule will never be added to
			// RefContainer.
			return new ElementRule( reader.pool, c, contentModel );
		} catch( DatatypeException e ) {
			// derivation failed
			reader.reportError( e, reader.ERR_BAD_TYPE, e.getMessage() );
			// recover by using harmless expression. anything will do.
			return Expression.nullSet;
		}
	}
}