pstlab / KOaLaR

import java.io.BufferedWriter;

import java.io.File;

import java.io.FileWriter;

import java.io.IOException;

import java.io.PrintWriter;

import java.util.ArrayList;

import java.util.HashSet;

import java.util.List;

import java.util.Set;

import org.apache.jena.rdf.model.Property;

import org.apache.jena.rdf.model.Resource;

import org.apache.jena.rdf.model.Statement;

import it.cnr.istc.pst.cognition.koala.reasoner.goal.GoalReasoner;

import it.cnr.istc.pst.cognition.koala.reasoner.observation.ObservationReasoner;

import it.cnr.istc.pst.cognition.koala.reasoner.observation.ObservationReasonerUpdate;

/**

 * 

 * @author anacleto

 *

 */

public class OWLKoalaGoalReasoner extends GoalReasoner

{

	private OWLKoalaModel kb;								// knowledge base model

	private Set<Statement> cache;						// cache of inferred statements about assistive tasks

	private PrintWriter writer;

	private long inferenceTime;							// count time spent doing inference

	private int inferenceCounter;						// count number of inferred goals

	/**

	 * 

	 * @param ontologyFilePath

	 * @param ruleFilePath

	 */

	public OWLKoalaGoalReasoner(String ontologyFilePath, String ruleFilePath) {

		super();

		// create a knowledge-base instance

		this.kb = new OWLKoalaModel(ontologyFilePath, ruleFilePath);

		// initialize cache

		this.cache = new HashSet<Statement>();

		this.inferenceTime = 0;

		this.inferenceCounter = 0;

	}

	/**

	 * 

	 */

	}

	/**

	 * 

	 */

	@Override

	protected void doGoalTriggering(List<ObservationReasonerUpdate> notifications) 

	{

		// get current time

		long timestamp = System.currentTimeMillis();

		// handle notifications

		for (ObservationReasonerUpdate notification : notifications) 

		{

			// current time 

			long now = System.currentTimeMillis();

			try

			{

				// event type

				String typeUri = notification.getEventType();

				// propagate information into the knowledge base

				Resource event = this.kb.createIndividual(typeUri);

				// get associated observable feature

				Resource observableFeature = this.kb.getResource(notification.getConcernedFeatureId());

				// get concerns property

				Property concerns = this.kb.getProperty(OWLKoalaNameSpace.KOALA.getNs() + "concerns");

				// assert property

				this.kb.assertProperty(

						event.getURI(), 

						concerns.getURI(), 

						observableFeature.getURI());

				System.out.println("[GoalReasoner] Update received from observation reasoner\n"

						+ "\t- " + event + "\n"

						+ "\t- asserting property " + event.getURI() + " " + concerns.getURI() + " " + observableFeature.getURI());

			}

			catch (Exception ex) {

				System.err.println("[GoalReasoner] Error while handling notification\n"

						+ "- notification: " + notification + "\n"

						+ "- message: " + ex.getMessage());

			}

			finally {

				// compute inference time

				long time = System.currentTimeMillis() - now;

				// update counter

				this.inferenceTime += time;

			}

		}

		try

		{

			// get the list of inferred events

			List<Statement> list = this.kb.getStatements(

					OWLKoalaNameSpace.SSN.getNs() + "isProxyFor");

			// check inferred events

			for (Statement s : list) 

			{

				// check if already notified

				if (!this.cache.contains(s))

				{

					// update inference counter

					this.inferenceCounter++;

					// get statement elements

					Resource subject = s.getSubject();

					// get type property

					Property pType = this.kb.getProperty(OWLKoalaNameSpace.RDF.getNs() + "type");

					// get event property statement

					Statement pStatement = subject.getProperty(pType);

					// get inferred event type

					Resource taskType = pStatement.getResource();

					// get the observable feature associated

					Property supports = this.kb.getProperty(OWLKoalaNameSpace.KOALA.getNs()+ "supports");

					// get concerns property statement

					Statement sStatement = subject.getProperty(supports);

					// get supported service

					Resource serviceType = sStatement.getResource();

					// get "explanation"

					Property precProperty = this.kb.getProperty(OWLKoalaNameSpace.KOALA.getNs() + "hasPrecondition");

					// get precondition

					Resource precondition = subject.getProperty(precProperty).getResource();

					// events triggering goal

					List<Resource> events = new ArrayList<Resource>();

					// get events enabling assistive task

					List<Statement> eStatements = this.kb.getStatements(

							precondition.getLocalName(), 

							OWLKoalaNameSpace.DUL.getNs()+ "includesEvent", 

							null);

					for (Statement es : eStatements) {

						// add resource

						events.add(es.getResource());

					}

					// print some data

					System.out.println("[GoalReasoner] Assistive task detected:\n"

							+ "- task: " + taskType + "\n"

							+ "- supported-service: " + serviceType + "\n"

							+ "- triggering-event(s): " + events + "\n");

					// add statement to the cache

					this.cache.add(s);

				}

			}

		}

		catch (Exception ex) {

			System.err.println("[GoalReasoner] Error while checking inferred assistive tasks\n- message= " + ex.getMessage());

		}

		finally 

		{

			// write data

			if (this.writer != null) 

			{

				// print inferred task type and service type

				this.writer.print(timestamp + ";" + this.inferenceCounter + ";" + this.inferenceTime + "\n");

				// write record

				this.writer.flush();

			}

		}

	}

	/**

	 * 

	 */

	@Override

	protected void doClose() 

	{

		// check if writer has been opened

		if (this.writer != null) {

			// close writer

			writer.close();

		}

	}

}