/*
 * @(#)$Id: ComplexContentBodyState.java,v 1.10 2001/10/10 23:19:46 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.xmlschema;

import com.sun.msv.grammar.Expression;
import com.sun.msv.grammar.ReferenceContainer;
import com.sun.msv.grammar.xmlschema.AttributeWildcard;
import com.sun.msv.grammar.xmlschema.ComplexTypeExp;
import com.sun.msv.grammar.xmlschema.XMLSchemaSchema;
import com.sun.msv.reader.State;
import com.sun.msv.reader.SequenceState;
import com.sun.msv.util.StartTagInfo;

/**
 * used to parse restriction/extension element as a child of complexContent element.
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class ComplexContentBodyState extends SequenceState implements AnyAttributeOwner {
	
	/** ComplexType object that we are now constructing. */
	protected ComplexTypeExp parentDecl;
	
	/**
	 * if this state is used to parse <extension>, then true.
	 * if this state is used to parse <restension>, then false.
	 */
	protected boolean extension;
	
	protected ComplexContentBodyState( ComplexTypeExp parentDecl, boolean extension ) {
		this.parentDecl = parentDecl;
		this.extension = extension;
	}
	
	protected State createChildState( StartTagInfo tag ) {
		final XMLSchemaReader reader = (XMLSchemaReader)this.reader;
		
		State s;
		if( super.exp==Expression.epsilon ) {
			// model group must be the first expression child.
			s = reader.createModelGroupState(this,tag);
			if(s!=null )	return s;
		}
		
		// attribute, attributeGroup, and anyAttribtue can be specified
		// after content model is given.
		return reader.createAttributeState(this,tag);
	}

	public void setAttributeWildcard( AttributeWildcard local ) {
		parentDecl.wildcard = local;
	}
	
	protected Expression initialExpression() {
		// if nothing is specified, then empty
		return Expression.epsilon;
	}
	
	protected Expression annealExpression( Expression exp ) {
		// hook this ComplexTypeExp into the base type's restrictions list.
		
		final XMLSchemaReader reader = (XMLSchemaReader)this.reader;
		exp = super.annealExpression(exp);
		
		
		String refQName = startTag.getAttribute("base");
		if( refQName==null ) {
			reader.reportError( reader.ERR_MISSING_ATTRIBUTE, startTag.qName, "base" );
			return exp;
			// recover by abandoning proper derivation processing
		}
		
		String[] r = reader.splitQName(refQName);
		if(r==null) {
			reader.reportError( reader.ERR_UNDECLARED_PREFIX, refQName );
			return exp;
			// recover by abandoning proper derivation processing
		}
		
		if( reader.isSchemaNamespace(r[0]) && r[1].equals("anyType") )
			// derivation from anyType means this expression is the root of
			// derivation. So we don't have to connect this complex type to
			// the super class.
			return exp;
		
		ComplexTypeExp baseType =
			reader.getOrCreateSchema(r[0]/*uri*/).complexTypes.getOrCreate(r[1]/*local name*/);
		if( baseType==null )	return exp;	// recover by abandoning further processing of this declaration.
		
		reader.backwardReference.memorizeLink(baseType);
		
/*		if( extension )
			baseType.extensions.exp = reader.pool.createChoice(
											baseType.extensions.exp,
											parentDecl.selfWType );
			// actual content model will be <baseTypeContentModel>,<AddedContentModel>
		else
			baseType.restrictions.exp = reader.pool.createChoice(
											baseType.restrictions.exp,
											parentDecl.selfWType );
*/		
		// set other fields of the ComplexTypeExp.
		parentDecl.derivationMethod = extension?parentDecl.EXTENSION:parentDecl.RESTRICTION;
		parentDecl.complexBaseType = baseType;
		
		return combineToBaseType( baseType, exp );
	}

	/**
	 * combines the base type content model and this content model
	 */
	protected Expression combineToBaseType( ComplexTypeExp baseType, Expression addedExp ) {
		if( extension )
			return reader.pool.createSequence( baseType.body, addedExp );
		else
			return addedExp;
	}
}