/*
 * @(#)$Id: NameClassAndExpressionState.java,v 1.13 2001/10/18 23:52:13 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;

import com.sun.msv.util.StartTagInfo;
import com.sun.msv.reader.State;
import com.sun.msv.reader.SequenceState;
import com.sun.msv.grammar.*;
import com.sun.msv.grammar.AnyNameClass;

/**
 * Base implementation for ElementState and AttributeState
 * 
 * This class collects one name class and patterns
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public abstract class NameClassAndExpressionState extends SequenceState implements NameClassOwner
{
	protected NameClass nameClass=null;
	
	/**
	 * gets namespace URI to which this declaration belongs
	 */
	protected String getNamespace()
	{
		// usually, propagated "ns" attribute should be used
		return ((TREXBaseReader)reader).targetNamespace;
	}
	
	protected void startSelf()
	{
		super.startSelf();
		// if name attribtue is specified, use it.
		final String name = startTag.getCollapsedAttribute("name");

		if( name==null )	return;

		
		final int idx = name.indexOf(':');
		if( idx!=-1 )
		{// QName is specified. resolve this prefix.
			final String[] s = reader.splitQName(name);
			if(s==null)
			{
				reader.reportError( TREXBaseReader.ERR_UNDECLARED_PREFIX, name );
				// recover by using a dummy name
				nameClass = new SimpleNameClass( "", name );
			}
			else
				nameClass = new SimpleNameClass( s[0], s[1] );
		}
		else
			nameClass = new SimpleNameClass( getNamespace(), name );
	}
	public void onEndChild( NameClass p )
	{
		if( nameClass!=null )	// name class has already specified
			reader.reportError( TREXBaseReader.ERR_MORE_THAN_ONE_NAMECLASS );
		nameClass = p;
	}

	protected State createChildState( StartTagInfo tag )
	{
		if( nameClass==null )	// nameClass should be specified before content model.
		{
			State nextState = ((TREXBaseReader)reader).createNameClassChildState(this,tag);
			if( nextState!=null )	return nextState;
			
			// to provide better error message, analyze the situation further.
			// users tend to forget to supply nameClass and name attribute.
			
			nextState = reader.createExpressionChildState(this,tag);
			if( nextState !=null )
			{
				// OK. tag is recognized as an content model.
				// so probably this user forgot to specify name class.
				// report so and recover by assuming some NameClass
				reader.reportError( TREXBaseReader.ERR_MISSING_CHILD_NAMECLASS );
				nameClass = AnyNameClass.theInstance;
				return nextState;
			}
			else
				// probably this user made a typo. let the default handler reports an error
				return null;
		}
		else
			return reader.createExpressionChildState(this,tag);
	}
	
	protected void endSelf() {
		if( nameClass==null )
		{// name class is missing
			reader.reportError( TREXBaseReader.ERR_MISSING_CHILD_NAMECLASS );
			nameClass = AnyNameClass.theInstance;
		}
		
		super.endSelf();
	}
}