content: /*
   *  Copyright (C) 2010-2012 Stichting Akvo (Akvo Foundation)
   *
   *  This file is part of Akvo FLOW.
   *
   *  Akvo FLOW is free software: you can redistribute it and modify it under the terms of
   *  the GNU Affero General Public License (AGPL) as published by the Free Software Foundation,
   *  either version 3 of the License or any later version.
   *
   *  Akvo FLOW is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
   *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   *  See the GNU Affero General Public License included below for more details.
   *
   *  The full license text can also be seen at <http://www.gnu.org/licenses/agpl.html>.
   */
  
  package org.waterforpeople.mapping.analytics;
  
  import org.waterforpeople.mapping.analytics.dao.SurveyQuestionSummaryDao;
  import org.waterforpeople.mapping.domain.QuestionAnswerStore;
  
  import com.gallatinsystems.framework.analytics.summarization.DataSummarizer;
  import com.gallatinsystems.framework.domain.DataChangeRecord;
  import com.gallatinsystems.survey.dao.QuestionDao;
  import com.gallatinsystems.survey.domain.Question;
  
  /**
   * handles updates to questionSummary objects
   * 
   * @author Christopher Fagiani
   */
  public class SurveyQuestionSummaryUpdater implements DataSummarizer {
  
      public SurveyQuestionSummaryUpdater() {
      }
  
      @Override
      public String getCursor() {
          return null;
      }
  
      /**
       * handles changes to question responses by using the DataChangeRecord to decrement the question
       * response counts for the oldValue and increment the counts for the newValue in the
       * SurveyQuestionSummary.
       */
      @Override
      public boolean performSummarization(String key, String type, String value,
              Integer offset, String cursor) {
  
          DataChangeRecord changeRecord = new DataChangeRecord(value);
          QuestionDao qDao = new QuestionDao();
          Question q = qDao.getByKey(new Long(changeRecord.getId()));
          if (q != null && Question.Type.OPTION.equals(q.getType())) {
              SurveyQuestionSummaryDao
                      .incrementCount(
                              constructQAS(changeRecord.getId(),
                                      changeRecord.getOldVal()), -1);
              if (changeRecord.getNewVal() != null
                      && changeRecord.getNewVal().trim().length() > 0) {
                  SurveyQuestionSummaryDao.incrementCount(
                          constructQAS(changeRecord.getId(),
                                  changeRecord.getNewVal()), 1);
              }
          }
  
          return true;
      }
  
      /**
       * helper method to create a new QuestionAnswerStore object using the values passed in.
       * 
       * @param id
       * @param value
       * @return
       */
      private QuestionAnswerStore constructQAS(String id, String value) {
          QuestionAnswerStore qas = new QuestionAnswerStore();
          qas.setQuestionID(id);
          qas.setValue(value);
          return qas;
      }
  }
  