/*
 * @(#)$Id: ElementRuleBaseState.java,v 1.7 2003/09/11 19:00:18 kohsuke 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.grammar.Expression;
import com.sun.msv.grammar.NameClass;
import com.sun.msv.grammar.relax.ElementRule;
import com.sun.msv.grammar.relax.ElementRules;
import com.sun.msv.grammar.relax.TagClause;
import com.sun.msv.reader.SimpleState;
import com.sun.msv.reader.State;
import com.sun.msv.util.StartTagInfo;

/**
 * Base implementation for ElementRuleWithHedgeState and ElementRuleWithTypeState.
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
abstract class ElementRuleBaseState extends SimpleState
{
    protected TagClause clause;
    
    /** gets reader in type-safe fashion */
    protected RELAXCoreReader getReader() { return (RELAXCoreReader)reader; }
    
    /** gets content model of this elementRule */
    protected abstract Expression getContentModel();
    
    /** notification of inline tag element.
     * 
     * this method is called by InlineTagState after it is parsed
     */
    protected void onEndInlineClause( TagClause inlineTag )
    {
        if(clause!=null)
        {// more than one inline tag was specified
            reader.reportError( RELAXCoreReader.ERR_MORE_THAN_ONE_INLINE_TAG );
            // recover by ignoring previous local tag.
        }
        clause = inlineTag;
    }
    
    protected void endSelf() {
        String role = startTag.getAttribute("role");
        String label = startTag.getAttribute("label");
        
        if(role==null && label==null) {
            reader.reportError( RELAXCoreReader.ERR_MISSING_ATTRIBUTE_2,
                                "elementRule", "role", "label" );
            // recover from error by supplying dummy label
            label = "<undefined>";
        }
        
        if( label==null )    label=role;    // label attribute defaults to role attribute.
        
        if( clause==null ) {
            // inline <tag> element was not found.
            // role element must point to some TagClause
            if( role==null ) {
                reader.reportError( RELAXCoreReader.ERR_MISSING_ATTRIBUTE,
                                    "elementRule","role");
                // recover by assuming a harmless Clause
                clause = new TagClause();
                clause.nameClass = NameClass.ALL;
                clause.exp = Expression.nullSet;
            } else {
                clause = getReader().module.tags.getOrCreate(role);
            }
        }
        
        ElementRules er = getReader().module.elementRules.getOrCreate(label);
        getReader().setDeclaredLocationOf(er);    // remember where this ElementRules is defined
        
        er.addElementRule( reader.pool, new ElementRule( reader.pool, clause, getContentModel() ) );
        
        super.endSelf();
    }

    
    protected State createChildState( StartTagInfo tag )
    {
        if( tag.localName.equals("tag") )
            return getReader().getStateFactory().tagInline(this,tag);
        
        return null;    // otherwise unknown
    }
}
