/**

  * Copyright 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.osedu.org/licenses/ECL-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.kuali.student.common.util.krms.proposition;

 import org.apache.commons.collections.CollectionUtils;

 import org.kuali.rice.krms.api.engine.ExecutionEnvironment;

 import org.kuali.rice.krms.api.engine.ResultEvent;

 import org.kuali.rice.krms.api.engine.Term;

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

 import org.kuali.rice.krms.framework.engine.result.BasicResult;

 import org.kuali.student.common.util.krms.RulesExecutionConstants;

 import java.util.Collection;

 import java.util.Collections;

 /**

  * Proposition class that checks for completion of no more than N of the given courses

  */

 public class MaxCourseCompletionProposition extends AbstractLeafProposition {

     private final String courseSetId;

     private final String singleCourseId;

     private final Integer maxCoursesCompleted;

     public MaxCourseCompletionProposition(String singleCourseId) {

         this.courseSetId = null;

         this.singleCourseId = singleCourseId;

         this.maxCoursesCompleted = 0;

     }

     public MaxCourseCompletionProposition(String courseSetId, Integer maxCourses) {

         this.courseSetId = courseSetId;

         this.singleCourseId = null;

         this.maxCoursesCompleted = maxCourses;

     }

     @Override

     public PropositionResult evaluate(ExecutionEnvironment environment) {

         Collection<String> completedCourses = environment.resolveTerm(RulesExecutionConstants.completedCourseIdsTerm, this);

         Collection<String> coursesToCheck;

         if(singleCourseId == null) {

             Term term = new Term(RulesExecutionConstants.COURSE_SET_TERM_NAME, Collections.singletonMap(RulesExecutionConstants.COURSE_SET_ID_TERM_PROPERTY, courseSetId));

             coursesToCheck = environment.resolveTerm(term, this);

         }

         else {

             coursesToCheck = Collections.singleton(singleCourseId);

         }

         PropositionResult result = new PropositionResult(CollectionUtils.intersection(completedCourses, coursesToCheck).size() <= maxCoursesCompleted);

         environment.getEngineResults().addResult(new BasicResult(ResultEvent.PROPOSITION_EVALUATED, this, environment, result.getResult()));

         return result;

     }

 }