/**
    * 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;
      }
  }