/**
 * Copyright 2005 JBoss Inc
 *
 * 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.workflow.instance.node;

import org.drools.common.InternalKnowledgeRuntime;
import org.drools.runtime.StatefulKnowledgeSession;
import org.drools.runtime.process.EventListener;
import org.drools.runtime.process.NodeInstance;
import org.drools.runtime.rule.impl.InternalAgenda;
import org.jbpm.workflow.core.node.RuleSetNode;

/**
 * Runtime counterpart of a ruleset node.
 * 
 * @author <a href="mailto:kris_verlaenen@hotmail.com">Kris Verlaenen</a>
 */
public class RuleSetNodeInstance extends StateBasedNodeInstance implements EventListener {

    private static final long serialVersionUID = 510l;

    protected RuleSetNode getRuleSetNode() {
        return (RuleSetNode) getNode();
    }

    public void internalTrigger(final NodeInstance from, String type) {
    	super.internalTrigger(from, type);
    	if ( !org.jbpm.workflow.core.Node.CONNECTION_DEFAULT_TYPE.equals( type ) ) {
            throw new IllegalArgumentException( "A RuleSetNode only accepts default incoming connections!" );
        }
        addRuleSetListener();
        ((InternalAgenda) getProcessInstance().getKnowledgeRuntime().getAgenda())
        	.activateRuleFlowGroup( getRuleSetNode().getRuleFlowGroup(), getProcessInstance().getId(), getUniqueId() );
    }

    public void addEventListeners() {
        super.addEventListeners();
        addRuleSetListener();
    }
    
    private String getRuleSetEventType() {
    	InternalKnowledgeRuntime kruntime = getProcessInstance().getKnowledgeRuntime();
    	if (kruntime instanceof StatefulKnowledgeSession) {
    		return "RuleFlowGroup_" + getRuleSetNode().getRuleFlowGroup() + "_" + ((StatefulKnowledgeSession) kruntime).getId();
    	} else {
    		return "RuleFlowGroup_" + getRuleSetNode().getRuleFlowGroup();
    	}
    }
    
    private void addRuleSetListener() {
    	getProcessInstance().addEventListener(getRuleSetEventType(), this, true);
    }

    public void removeEventListeners() {
        super.removeEventListeners();
    	getProcessInstance().removeEventListener(getRuleSetEventType(), this, true);
    }

    public void cancel() {
        super.cancel();
        ((InternalAgenda) getProcessInstance().getKnowledgeRuntime().getAgenda())
        	.deactivateRuleFlowGroup( getRuleSetNode().getRuleFlowGroup() );
    }

	public void signalEvent(String type, Object event) {
		if (getRuleSetEventType().equals(type)) {
            removeEventListeners();
            triggerCompleted();
		}
    }

}
