/**

  * Copyright 2005-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.kuali.rice.krms.impl.provider.repository;

 import java.util.ArrayList;

 import java.util.List;

 import org.kuali.rice.krms.api.repository.LogicalOperator;

 import org.kuali.rice.krms.api.repository.proposition.PropositionDefinition;

 import org.kuali.rice.krms.api.repository.proposition.PropositionType;

 import org.kuali.rice.krms.framework.engine.CompoundProposition;

 import org.kuali.rice.krms.framework.engine.Proposition;

 import org.kuali.rice.krms.framework.type.PropositionTypeService;

 /**

  * An implementation of {@link PropositionTypeService} which loads a {@link CompoundProposition}

  * from the given {@link PropositionDefinition}.  A compound proposition contains one

  * or more propositions which are evaluated in conjunction with a logical operator

  * such as "AND" or "OR".

  * 

  * <p>The proposition given to the {@link #loadProposition(PropositionDefinition)}

  * method must be of type {@link PropositionType#COMPOUND}.

  * 

  * <p>The translation from a {@link PropositionDefinition} to a {@link Proposition}

  * is performed by the given {@link RepositoryToEngineTranslator}.  This must be

  * set on this class before it is used.

  * 

  * <p>This class is thread-safe and is designed to be wired as a singleton bean in

  * Spring.

  * 

  * @see CompoundProposition

  * @see RepositoryToEngineTranslator

  * 

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

  *

  */

 public class CompoundPropositionTypeService implements PropositionTypeService {

         private RepositoryToEngineTranslator translator;

         @Override

         public Proposition loadProposition(PropositionDefinition propositionDefinition) {

                 if (translator == null) {

                         throw new IllegalStateException("Service not configured properly, no translator available.");

                 }

                 if (propositionDefinition == null) {

                         throw new IllegalArgumentException("propositionDefinition was null");

                 }

                 if (PropositionType.COMPOUND != PropositionType.fromCode(propositionDefinition.getPropositionTypeCode())) {

                         throw new IllegalArgumentException("Given proposition definition was not compound, type code was: " + propositionDefinition.getPropositionTypeCode());

                 }

                 List<Proposition> propositions = new ArrayList<Proposition>();

                 for (PropositionDefinition subProp : propositionDefinition.getCompoundComponents()) {

                         propositions.add(translator.translatePropositionDefinition(subProp));

                 }

                 LogicalOperator operator = LogicalOperator.fromCode(propositionDefinition.getCompoundOpCode());

                 return new CompoundProposition(operator, propositions);

         }

         /**

          * Sets the translator on this service to the given translator.

          * 

          * @param translator the translator to set on this service

          */

         public void setTranslator(RepositoryToEngineTranslator translator) {

                 this.translator = translator;

         }

 }