/**
 * Copyright 2010 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.drools.examples.ruleflow;

import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.io.ResourceFactory;
import org.drools.runtime.StatefulKnowledgeSession;
import org.drools.runtime.process.WorkItem;
import org.drools.runtime.process.WorkItemHandler;
import org.drools.runtime.process.WorkItemManager;

public class WorkItemExample {

    public static final void main(String[] args) {
        try {
            KnowledgeBase knowledgeBase = readRule();
            StatefulKnowledgeSession ksession = knowledgeBase.newStatefulKnowledgeSession();

            // logging all work items to System.out
            WorkItemHandler handler = new WorkItemHandler() {
				public void executeWorkItem(WorkItem workItem, WorkItemManager manager) {
					System.out.println("Executing work item " + workItem);
			        manager.completeWorkItem(workItem.getId(), null);
				}
            	
				public void abortWorkItem(WorkItem workItem, WorkItemManager manager) {
					// Do nothing
				}
            };
            ksession.getWorkItemManager().registerWorkItemHandler( "Email", handler );
            ksession.getWorkItemManager().registerWorkItemHandler( "Log", handler );

            ksession.startProcess( "com.sample.ruleflow" );
            ksession.fireAllRules();
        } catch ( Throwable t ) {
            t.printStackTrace();
        }
    }

    private static KnowledgeBase readRule() throws Exception {
        KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();        
        kbuilder.add( ResourceFactory.newClassPathResource( "workitems.rf", WorkItemExample.class ),
                              ResourceType.DRF );

        KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
        kbase.addKnowledgePackages( kbuilder.getKnowledgePackages() );

        return kbase;
    }

}