/**
    * Copyright 2013 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.
   *
   * Created by Charles on 9/24/13
   */
  package org.kuali.student.poc.eventproc.handler.impl;
  
  import org.apache.log4j.Logger;
  import org.kuali.student.enrollment.courseoffering.dto.ActivityOfferingInfo;
  import org.kuali.student.poc.eventproc.api.KSHandler;
  import org.kuali.student.poc.eventproc.api.KSInternalEventProcessor;
  import org.kuali.student.poc.eventproc.event.KSEvent;
  import org.kuali.student.poc.eventproc.event.KSEventFactory;
  import org.kuali.student.poc.eventproc.event.KSHandlerResult;
  import org.kuali.student.poc.eventproc.event.KSEventType;
  import org.kuali.student.poc.eventproc.event.subclass.event.KSAOStateModifiedEvent;
  import org.kuali.student.r2.common.dto.ContextInfo;
  import org.kuali.student.r2.common.exceptions.DataValidationErrorException;
  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 org.kuali.student.r2.common.exceptions.ReadOnlyException;
  import org.kuali.student.r2.common.exceptions.VersionMismatchException;
  import org.kuali.student.r2.common.util.constants.CourseOfferingServiceConstants;
  import org.kuali.student.r2.common.util.constants.LuiServiceConstants;
  import org.kuali.student.r2.core.scheduling.dto.ScheduleRequestInfo;
  import org.kuali.student.r2.core.scheduling.dto.ScheduleRequestSetInfo;
  
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Listens for state modified event to cancel/draft and drops ADLs
   *
   * @author Kuali Student Team
   */
  public class ActivityOfferingDropADLsHandler implements KSHandler {
      public static final Logger LOGGER = Logger.getLogger(ActivityOfferingDropADLsHandler.class);
      KSInternalEventProcessor processor;
  
      public ActivityOfferingDropADLsHandler(KSInternalEventProcessor processor) {
          this.processor = processor;
      }
  
      @Override
      public boolean handlesEvent(KSEvent event) {
          if (!(event instanceof KSAOStateModifiedEvent)) {
              return false;
          }
          KSAOStateModifiedEvent stateModifiedEvent = (KSAOStateModifiedEvent) event;
          // Must be ao state modified event--fetch to state
          String toState = stateModifiedEvent.getToState();
          // Only handles if toState is draft/canceled
          boolean result = LuiServiceConstants.LUI_AO_STATE_CANCELED_KEY.equals(toState) ||
                  LuiServiceConstants.LUI_AO_STATE_DRAFT_KEY.equals(toState);
          return result;
      }
  
      @Override
      public KSHandlerResult processEvent(KSEvent event, ContextInfo context)
              throws PermissionDeniedException, MissingParameterException, InvalidParameterException, OperationFailedException, DoesNotExistException, ReadOnlyException, DataValidationErrorException, VersionMismatchException {
          if (!handlesEvent(event)) {
              return new KSHandlerResult(KSHandlerResult.FAIL_HANDLER_WONT_PROCESS, ActivityOfferingDropADLsHandler.class);
          }
          KSAOStateModifiedEvent stateModifiedEvent = (KSAOStateModifiedEvent) event;
          String aoId = stateModifiedEvent.getAoId();
          ActivityOfferingInfo aoInfo = processor.getCoService().getActivityOffering(aoId, context);
          List<ScheduleRequestSetInfo> srsList =
                  processor.getSchedulingService().getScheduleRequestSetsByRefObject(CourseOfferingServiceConstants.REF_OBJECT_URI_ACTIVITY_OFFERING, aoId, context);
          ScheduleRequestSetInfo srs = null;
          if (srsList.size() == 1) {
              // Not able to handle multiple SRS yet (partial colocation, etc)
              srs = srsList.get(0);
          } else {
              throw new OperationFailedException("Expecting SRS list to be size 1: actual size = " + srsList.size());
          }
          if (srs.getRefObjectIds().size() > 1) {
              // This AO is co-located, so just remove the schedule IDs, but do not delete them
              if (aoInfo.getScheduleIds() == null || aoInfo.getScheduleIds().isEmpty()) {
                  LOGGER.info("AO has no ADLs to remove");
              } else {
                  // Empty it out
                  LOGGER.info("Removing ADLs from AO");
                  aoInfo.setScheduleIds(new ArrayList<String>());
                  processor.getCoService().updateActivityOffering(aoInfo.getId(), aoInfo, context);
              }
         } else if (srs.getRefObjectIds().size() == 1) {
             for (String scheduleId: aoInfo.getScheduleIds()) {
                 processor.getSchedulingService().deleteSchedule(scheduleId, context);
             }
             // Empty it out
             LOGGER.info("Removing ADLs from AO");
             aoInfo.setScheduleIds(new ArrayList<String>());
             processor.getCoService().updateActivityOffering(aoInfo.getId(), aoInfo, context);
             List<ScheduleRequestInfo> requests =
                     processor.getSchedulingService().getScheduleRequestsByScheduleRequestSet(srs.getId(), context);
             for (ScheduleRequestInfo request: requests) {
                 // Clear out the schedule IDs from the schedule (should this really be done by updateSR?) --cclin
                 request.setScheduleId(null);
                 processor.getSchedulingService().updateScheduleRequest(request.getId(), request, context);
             }
         }
         return new KSHandlerResult(KSHandlerResult.SUCCESS, ActivityOfferingDropADLsHandler.class);
     }
 
     @Override
     public String getName() {
         return ActivityOfferingDropADLsHandler.class.getSimpleName();
     }
 
     @Override
     public void setEventProcessor(KSInternalEventProcessor processor) {
         this.processor = processor;
     }
 
     @Override
     public List<KSEventType> getEventTypesHandled() {
         List<KSEventType> result = new ArrayList<KSEventType>();
         result.add(KSEventFactory.AO_STATE_MODIFIED_EVENT_TYPE);
         return result;
     }
 }