/*
 * 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.drools.core.reteoo.builder;

import org.drools.core.reteoo.CoreComponentFactory;
import org.drools.core.rule.Pattern;
import org.drools.core.rule.QueryElement;
import org.drools.core.rule.RuleConditionElement;


public class QueryElementBuilder
    implements
    ReteooComponentBuilder {

    /**
     * @inheritDoc
     */
    public void build(final BuildContext context,
                      final BuildUtils utils,
                      final RuleConditionElement rce) {

        final QueryElement qe = (QueryElement) rce;
        context.pushRuleComponent( qe );

        Pattern   resultPattern = qe.getResultPattern();
        final int tupleIndex    = context.getTupleSource() == null ? 0 : context.getTupleSource().getPathIndex() + 1;

        resultPattern.setTupleIndex(tupleIndex);
        resultPattern.setObjectIndex((context.getTupleSource() != null) ? context.getTupleSource().getObjectCount() : 0);

        context.setTupleSource( utils.attachNode( context,
                CoreComponentFactory.get().getNodeFactoryService().buildQueryElementNode(
                                                                        context.getNextNodeId(),
                                                                        context.getTupleSource(),
                                                                        qe,
                                                                        context.isTupleMemoryEnabled(),
                                                                        qe.isOpenQuery(),
                                                                        context ) ) );
        
        context.popRuleComponent();
    }

    /**
     * @inheritDoc
     */
    public boolean requiresLeftActivation(final BuildUtils utils,
                                          final RuleConditionElement rce) {
        return true;
    }

}
