package org.kuali.rice.krms.api.engine;

 import java.util.Map;

 import java.util.Set;

 /**

  * The ExecutionEnvironment manages contextual information which is made available to

  * different components of the rules engine during execution.  Facts can be retrieved

  * from and published to the environment.  It also provides a reference to the

  * {@link EngineResults} or tracking engine activity and returning values back to

  * the client of the rules engine.

  * 

  * @author Kuali Rice Team (rice.collab@kuali.org)

  *

  */

 public interface ExecutionEnvironment {

         /**

          * Returns the selection criteria that was used to initialize the environment.

          * 

          * @return the selection criteria for this environment

          */

         public SelectionCriteria getSelectionCriteria();

         /**

          * Returns an immutable Map of facts available within this environment.

          * 

          * @return the facts in this environment

          */

         public Map<Term, Object> getFacts();

         /**

          * Publishes a new fact

          * 

          * @param factName name of the fact to publish

          * @param factValue value of the fact to publish

          * // TODO: we don't support updating facts, refactor this method

          * @return true if an existing fact was updated, false if this was a new fact

          */

         public boolean publishFact(Term factName, Object factValue);

         public void addTermResolver(TermResolver<?> termResolver);

         public <T> T resolveTerm(Term term, Object caller) throws TermResolutionException;

         public Set<Term> getTermsForCaller(Object caller);

         public ExecutionOptions getExecutionOptions();

         public EngineResults getEngineResults();

 }