package org.kuali.student.enrollment.class2.courseregistration.termresolver;

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

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

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

 import org.kuali.student.enrollment.courseoffering.dto.CourseOfferingInfo;

 import org.kuali.student.enrollment.courseregistration.dto.CourseRegistrationInfo;

 import org.kuali.student.enrollment.courseregistration.service.CourseRegistrationService;

 import org.kuali.student.r2.common.dto.ContextInfo;

 import org.kuali.student.r2.common.exceptions.DisabledIdentifierException;

 import org.kuali.student.r2.common.exceptions.DoesNotExistException;

 import org.kuali.student.r2.common.exceptions.InvalidParameterException;

 import org.kuali.student.r2.common.exceptions.MissingParameterException;

 import org.kuali.student.r2.common.exceptions.OperationFailedException;

 import org.kuali.student.r2.common.exceptions.PermissionDeniedException;

 import java.util.ArrayList;

 import java.util.Collection;

 import java.util.Collections;

 import java.util.HashSet;

 import java.util.List;

 import java.util.Map;

 import java.util.Set;

 public class EnrolledCoursesResolver implements TermResolver<Collection<String>> {

     private CourseRegistrationService courseRegService;

     private final static Set<String> prerequisites = new HashSet<String>(2);

     static {

         prerequisites.add(RulesExecutionConstants.STUDENT_ID_TERM_NAME);

         prerequisites.add(RulesExecutionConstants.CONTEXT_INFO_TERM_NAME);

     }

     @Override

     public Set<String> getPrerequisites() {

         return prerequisites;

     }

     @Override

     public String getOutput() {

         return RulesExecutionConstants.STUDENT_ENROLLED_COURSE_IDS_TERM_NAME;

     }

     @Override

     public Set<String> getParameterNames() {

         return Collections.emptySet();

     }

     @Override

     public int getCost() {

         // TODO analyze actual cost

         return 0;

     }

     @Override

     public Collection<String> resolve(Map<String, Object> resolvedPrereqs, Map<String, String> parameters) throws TermResolutionException {

         String studentId = resolvedPrereqs.get(RulesExecutionConstants.STUDENT_ID_TERM_NAME).toString();

         ContextInfo context = (ContextInfo) resolvedPrereqs.get(RulesExecutionConstants.CONTEXT_INFO_TERM_NAME);

         Collection<String> results = null;

         try {

             List<CourseRegistrationInfo> registrations = courseRegService.getCourseRegistrationsByStudent(studentId, context);

             results = new ArrayList<String>(registrations.size());

             for (CourseRegistrationInfo courseRegInfo : registrations) {

                 if (courseRegInfo.getCourseOfferingId() != null) {

                     results.add(courseRegInfo.getCourseOfferingId());

                 }

             }

         } catch (InvalidParameterException e) {

             throw new TermResolutionException(e.getMessage(), this, parameters, e);

         } catch (MissingParameterException e) {

             throw new TermResolutionException(e.getMessage(), this, parameters, e);

         } catch (OperationFailedException e) {

             throw new TermResolutionException(e.getMessage(), this, parameters, e);

         } catch (PermissionDeniedException e) {

             throw new TermResolutionException(e.getMessage(), this, parameters, e);

         }

         return results;

     }

 }