/*
 * @(#)$Id: IncludeMergeState.java,v 1.2 2001/06/05 01:59:45 Bear 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.trex.ng;

import java.util.Set;
import com.sun.msv.reader.ChildlessState;
import com.sun.msv.reader.ExpressionOwner;
import com.sun.msv.reader.State;
import com.sun.msv.grammar.Expression;
import com.sun.msv.grammar.ReferenceExp;
import com.sun.msv.util.StartTagInfo;

/**
 * parses <include> element as a child of <grammar> element.
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class IncludeMergeState extends com.sun.msv.reader.trex.IncludeMergeState
			implements ExpressionOwner {
	
	protected State createChildState( StartTagInfo tag ) {
		final RELAXNGReader reader = (RELAXNGReader)this.reader;
		if(tag.localName.equals("define"))	return reader.getStateFactory().redefine(this,tag);
		return null;
	}
	
	/** set of ReferenceExps which are redefined by this inclusion. */
	private final Set redefinedPatterns = new java.util.HashSet();
	
	// this class has to implement ExpressionOwner because
	// <define> state requires this interface.
	public void onEndChild( Expression child ) {
		// if child <define> element has an error,
		// then it may not return ReferenceExp.
		if(!(child instanceof ReferenceExp))	return;
		
		redefinedPatterns.add(child);
	}
	
	public void endSelf() {
		final RELAXNGReader reader = (RELAXNGReader)this.reader;
		
		ReferenceExp[] patterns = (ReferenceExp[])redefinedPatterns.toArray(new ReferenceExp[0]);
		RELAXNGReader.RefExpParseInfo[] old = new RELAXNGReader.RefExpParseInfo[patterns.length];
		
		// back-up the current values of RefExpParseInfo,
		// and reset the values.
		for( int i=0; i<patterns.length; i++ ) {
			RELAXNGReader.RefExpParseInfo info = reader.getRefExpParseInfo(patterns[i]);
			
			old[i] = new RELAXNGReader.RefExpParseInfo();
			old[i].set( info );
			info.haveHead = false;
			info.combineMethod = null;
			info.redefinition = info.originalNotFoundYet;
		}
		
		// process inclusion.
		super.endSelf();
		
		// make sure that originals are found.
		for( int i=0; i<patterns.length; i++ ) {
			RELAXNGReader.RefExpParseInfo info = reader.getRefExpParseInfo(patterns[i]);
			
			if( info.redefinition==info.originalNotFoundYet )
				// the original definition was not found.
				reader.reportError( reader.ERR_REDEFINING_UNDEFINED, patterns[i].name );

			// then restore the values.
			reader.getRefExpParseInfo(patterns[i]).set( old[i] );
		}
	}
}