package org.drools.workflow.instance.node;



/*

 * 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.

 */



import org.drools.WorkingMemory;

import org.drools.base.DefaultKnowledgeHelper;

import org.drools.base.SequentialKnowledgeHelper;

import org.drools.common.InternalRuleBase;

import org.drools.spi.Action;

import org.drools.spi.ProcessContext;

import org.drools.spi.KnowledgeHelper;

import org.drools.workflow.core.Node;

import org.drools.workflow.core.node.ActionNode;

import org.drools.workflow.instance.NodeInstance;

import org.drools.workflow.instance.impl.NodeInstanceImpl;



/**

 * Runtime counterpart of an action node.

 * 

 * @author <a href="mailto:kris_verlaenen@hotmail.com">Kris Verlaenen</a>

 */

public class ActionNodeInstance extends NodeInstanceImpl {



    private static final long serialVersionUID = 400L;



    protected ActionNode getActionNode() {

        return (ActionNode) getNode();

    }



    public void internalTrigger(final NodeInstance from, String type) {

        if (!Node.CONNECTION_DEFAULT_TYPE.equals(type)) {

            throw new IllegalArgumentException(

                "An ActionNode only accepts default incoming connections!");

        }

		Action action = (Action) getActionNode().getAction().getMetaData("Action");

		try {

		    KnowledgeHelper knowledgeHelper = createKnowledgeHelper();

		    ProcessContext context = new ProcessContext();

		    context.setNodeInstance(this);

	        action.execute(knowledgeHelper, getProcessInstance().getWorkingMemory(), context);		    

		} catch (Exception e) {

		    throw new RuntimeException("unable to execute Action", e);

		}

    	triggerCompleted();

    }



    public void triggerCompleted() {

        triggerCompleted(Node.CONNECTION_DEFAULT_TYPE, true);

    }

    

    private KnowledgeHelper createKnowledgeHelper() {

        WorkingMemory workingMemory = getProcessInstance().getWorkingMemory();

        if ( ((InternalRuleBase) workingMemory.getRuleBase()).getConfiguration().isSequential() ) {

            return new SequentialKnowledgeHelper( workingMemory );

        } else {

            return new DefaultKnowledgeHelper( workingMemory );

        }

    }



}