/*
    * Copyright 2009 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.opensource.org/licenses/ecl2.php
    * 
   * 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.ole.sys.businessobject;
  
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.kuali.ole.sys.context.SpringContext;
  import org.kuali.rice.kns.service.DataDictionaryService;
  import org.kuali.rice.krad.bo.BusinessObject;
  import org.kuali.rice.krad.datadictionary.AttributeDefinition;
  
  /**
   * An abstract class which provides help in determining field lengths of business objects being parsed from Strings
   */
  public abstract class BusinessObjectStringParserFieldUtils {
      protected org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(getClass());
      private Map<String, Integer> fieldLengthMap;
      private Map<String, Integer> fieldBeginningPositionMap;
      
      /**
       * @return a Map with attribute names as keys and lengths of how long those fields are specified to be in the DataDictionary as values
       */
      public Map<String, Integer> getFieldLengthMap() {
          if (fieldLengthMap == null) {
              initializeFieldLengthMap();
          }
          return fieldLengthMap;
      }
      
      /**
       * Calculates a map with the field length of all of the attributes of the class given by the
       * getBusinessObjectClass method
       */
      protected void initializeFieldLengthMap() {
          fieldLengthMap = new HashMap<String, Integer>();
          DataDictionaryService dataDictionaryService = SpringContext.getBean(DataDictionaryService.class);
          List<AttributeDefinition> attributes = dataDictionaryService.getDataDictionary().getBusinessObjectEntry(getBusinessObjectClass().getName()).getAttributes();
  
          for (AttributeDefinition attributeDefinition : attributes) {
              Integer fieldLength;
              fieldLength = dataDictionaryService.getAttributeMaxLength(getBusinessObjectClass(), attributeDefinition.getName());
              fieldLengthMap.put(attributeDefinition.getName(), fieldLength);
          }
      }
      
      /**
       * @return the class of the BusinessObject that this utility class will help parse from a String
       */
      public abstract Class<? extends BusinessObject> getBusinessObjectClass();
  
      /**
       * @return a Map with business object field names as keys and starting positions of each field in the String as values
       */
      public Map<String, Integer> getFieldBeginningPositionMap() {
          if (fieldBeginningPositionMap == null) {
              initializeFieldBeginningPositionMap();
          }
          return fieldBeginningPositionMap;
      }
      
      /**
       * Calculates the beginning positions of each field in the array returned by getOrderedProperties, based on
       * the length map calculated by getFieldLengthMap().
       */
      protected void initializeFieldBeginningPositionMap() {
          fieldBeginningPositionMap = new HashMap<String, Integer>();
          Map<String, Integer> lengthMap = getFieldLengthMap();
          
          int lengthTracker = 0;
     
          for (String property : getOrderedProperties()) {
              fieldBeginningPositionMap.put(property, new Integer(lengthTracker));
              if (LOG.isDebugEnabled()) {
                  LOG.debug("Finding position for property: "+property+"; length = "+lengthMap.get(property));
              }
              lengthTracker += lengthMap.get(property).intValue();
          }
      }
      
      /**
       * @return an array of String names of fields in a business object in the order they will show up in the String to be parsed
       */
      public abstract String[] getOrderedProperties();
  }