/*
 * Copyright 2005 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.drools.compiler.compiler.xml.rules;

import org.drools.compiler.lang.descr.ConnectiveDescr;
import org.drools.compiler.lang.descr.ConnectiveDescr.RestrictionConnectiveType;
import org.drools.compiler.lang.descr.ExprConstraintDescr;
import org.drools.compiler.lang.descr.PatternDescr;
import org.drools.compiler.lang.descr.RestrictionConnectiveDescr;
import org.drools.core.xml.BaseAbstractHandler;
import org.drools.core.xml.ExtensibleXmlParser;
import org.drools.core.xml.Handler;
import org.w3c.dom.Element;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

/**
 *
 * TODO To change the template for this generated type comment go to Window -
 * Preferences - Java - Code Style - Code Templates
 */
public class RestrictionConnectiveHandler extends BaseAbstractHandler
    implements
    Handler {

    public final static String AND = "and-";
    public final static String OR  = "or-";

   public RestrictionConnectiveHandler() {
    }

    public Object start(final String uri,
                        final String localName,
                        final Attributes attrs,
                        final ExtensibleXmlParser parser) throws SAXException {
        parser.startElementBuilder( localName,
                                    attrs );
        
        if ( localName.startsWith( RestrictionConnectiveHandler.OR ) ) {
            return new ConnectiveDescr(RestrictionConnectiveType.OR);    
        } else if ( localName.startsWith( RestrictionConnectiveHandler.AND ) ) {
            return new ConnectiveDescr(RestrictionConnectiveType.AND);   
        } else {
            throw new SAXParseException( "<" + localName + "> should have'",
                                         parser.getLocator() );
        }
        
        
    }

    public Object end(final String uri,
                      final String localName,
                      final ExtensibleXmlParser parser) throws SAXException {
        final Element element = parser.endElementBuilder();
        
        Object op = parser.getParent();
        ConnectiveDescr c = (ConnectiveDescr) parser.getCurrent();
        
        if ( op instanceof PatternDescr ) {
            StringBuilder sb = new StringBuilder();
            c.buildExpression( sb );
                  
            ExprConstraintDescr expr = new ExprConstraintDescr( );
            expr.setExpression( sb.toString() );
              
            final PatternDescr patternDescr = (PatternDescr)op;  
            patternDescr.addConstraint( expr );    
        } else {        
            ConnectiveDescr p = (ConnectiveDescr)op;
            p.add( c );
        }
        return c;
    }

    public Class generateNodeFor() {
        return RestrictionConnectiveDescr.class;
    }
}