/*

  * Copyright 2007-2008 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.rice.kns.web.ui;

 import javax.servlet.jsp.PageContext;

 import org.apache.commons.lang.StringUtils;

 import org.displaytag.decorator.DisplaytagColumnDecorator;

 import org.displaytag.exception.DecoratorException;

 import org.displaytag.properties.MediaTypeEnum;

 import org.kuali.rice.kns.util.KNSConstants;

 import org.kuali.rice.kns.web.comparator.CellComparatorHelper;

 /** @see #decorate(Object, PageContext, MediaTypeEnum) */

 public class FormatAwareDecorator implements DisplaytagColumnDecorator {

     /**

      * Empty values don't show up properly in HTML. So, the String " " is substituted for an empty or null value of cellValue

      * if mediaType is MediaTypeEnum.HTML. If mediaType is not {@link MediaTypeEnum.HTML} and cellValue is not null, then

      * <code>CellComparatorHelper.getSanitizedValue(cellValue.toString())</code> is returned.

      * 

      * @param cellValue

      * @param pageContext

      * @param mediaType

      */

     public Object decorate(Object cellValue, PageContext pageContext, MediaTypeEnum mediaType) throws DecoratorException {

         if (null == cellValue) {

             return getEmptyStringFor(mediaType);

         }

         final String decoratedOutput;

         if (isCollection(cellValue)) {

                 decoratedOutput = createCollectionString(cellValue);

         } else {

                 decoratedOutput = MediaTypeEnum.HTML.equals(mediaType) ? cellValue.toString() : CellComparatorHelper.getSanitizedStaticValue(cellValue.toString());

         }

         return StringUtils.isBlank(decoratedOutput) ? getEmptyStringFor(mediaType) : StringUtils.trim(decoratedOutput);

     }

     /**

      * Takes a cellValue which is a collection and creates a String representations.

      * 

      * <p>

      * If a column resulting from lookup contains collection values, each of the collection entry

      * should be printed on one line (i.e. separated by a <br/>). If there is no entry in the

      * collection, then we'll just print an &nbsp for the column.

      * </p>

      * 

      * @param cellValue the cell value to convert

      * @return the string representation of the cell value

      */

     private static String createCollectionString(Object cellValue) {

             String decoratedOutput = "";

             String cellContentToBeParsed = cellValue.toString().substring(1, cellValue.toString().indexOf("]"));

         if (StringUtils.isNotBlank(cellContentToBeParsed)) {

             String[] parsed = cellContentToBeParsed.split(",");

             for (String elem : parsed) {

                 decoratedOutput = decoratedOutput + elem + "<br/>";                    

             }

         }

         return decoratedOutput;

     }

     /**

      * Checks if a cell value is a Collection

      * 

      * @param cellValue to check

      * @return true if a Collection

      */

     private static boolean isCollection(Object cellValue) {

             return cellValue != null && cellValue.toString().indexOf("[") == 0 && cellValue.toString().indexOf("]") > 0;

     }

     /**

      * Gets an empty string type based on the media type.

      * 

      * @param mediaType the media type

      * @return the empty string 

      */

     private static String getEmptyStringFor(MediaTypeEnum mediaType) {

             return MediaTypeEnum.HTML.equals(mediaType) ? "&nbsp" : KNSConstants.EMPTY_STRING;

     }

 }