/*
 * Copyright 2010 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.jbpm.compiler.xml.compiler.rules;

import org.drools.drl.ast.descr.AccumulateDescr;
import org.drools.drl.ast.descr.BaseDescr;
import org.jbpm.compiler.xml.Handler;
import org.jbpm.compiler.xml.Parser;
import org.jbpm.compiler.xml.core.BaseAbstractHandler;
import org.w3c.dom.Element;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;

public class AccumulateHelperHandler extends BaseAbstractHandler
        implements
        Handler {

    public AccumulateHelperHandler() {
    }

    public Object start(final String uri,
            final String localName,
            final Attributes attrs,
            final Parser parser) throws SAXException {

        parser.startElementBuilder(localName,
                attrs);

        return new BaseDescr();
    }

    public Object end(final String uri,
            final String localName,
            final Parser parser) throws SAXException {

        final Element element = parser.endElementBuilder();

        final String expression = ((org.w3c.dom.Text) element.getChildNodes().item(0)).getWholeText();

        final Object parent = parser.getParent();

        final AccumulateDescr accumulate = (AccumulateDescr) parent;

        if (localName.equals("init")) {
            emptyContentCheck(localName, expression, parser);
            accumulate.setInitCode(expression.trim());
        } else if (localName.equals("action")) {
            emptyContentCheck(localName, expression, parser);
            accumulate.setActionCode(expression.trim());
        } else if (localName.equals("result")) {
            emptyContentCheck(localName, expression, parser);
            accumulate.setResultCode(expression.trim());
        } else if (localName.equals("reverse")) {
            emptyContentCheck(localName, expression, parser);
            accumulate.setReverseCode(expression.trim());
        } else if (localName.equals("external-function")) {
            accumulate.addFunction(element.getAttribute("evaluator"),
                    null, // no support to bindings yet?
                    false,
                    new String[] { element.getAttribute("expression") });
        }

        return null;
    }

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

}
