/*

  * Copyright 2006-2008 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.core.web.format;

 import java.math.BigDecimal;

 import java.text.DecimalFormat;

 import java.text.ParseException;

 import java.util.regex.Pattern;

 import org.apache.log4j.Logger;

 import org.kuali.rice.core.util.RiceKeyConstants;

 /**

  * This class is used to format BigDecimal objects.

  */

 public class BigDecimalFormatter extends Formatter {

     private static Logger LOG = Logger.getLogger(BigDecimalFormatter.class);

     private static final Pattern DECIMAL_PATTERN = Pattern.compile("\\-?[0-9,]*\\.?[0-9]*");

     /**

      * Unformats its argument and returns a KualiDecimal instance initialized with the resulting string value

      * 

      * @see org.kuali.rice.core.web.format.Formatter#convertToObject(java.lang.String)

      */

     protected Object convertToObject(String target) {

         BigDecimal value = null;

         LOG.debug("convertToObject '" + target + "'");

         if (target != null) {

             // preemptively detect non-numeric-related symbols, since NumberFormat.parse seems to be silently deleting them

             // (i.e. 9aaaaaaaaaaaaaaa is silently converted into 9)

             if (!DECIMAL_PATTERN.matcher(target).matches()) {

                 throw new FormatException("parsing", RiceKeyConstants.ERROR_NUMERIC, target);

             }

             // actually reformat the numeric value

             DecimalFormat formatter = new DecimalFormat();

             formatter.setParseBigDecimal(true);

             try {

                 Number parsedNumber = formatter.parse(target);

                 value = new BigDecimal(parsedNumber.toString());

             }

             catch (NumberFormatException e) {

                 throw new FormatException("parsing", RiceKeyConstants.ERROR_BIG_DECIMAL, target, e);

             }

             catch (ParseException e) {

                 throw new FormatException("parsing", RiceKeyConstants.ERROR_BIG_DECIMAL, target, e);

             }

         }

         return value;

     }

     /**

      * Returns a string representation of its argument formatted as a decimal value.

      * 

      * @see org.kuali.rice.core.web.format.Formatter#format(java.lang.Object)

      */

     public Object format(Object obj) {

         LOG.debug("format '" + obj + "'");

         if (obj == null)

             return null;

         DecimalFormat formatter = new DecimalFormat();

         String string = null;

         try {

             BigDecimal number = (BigDecimal) obj;

             if(number!=null && number.scale()>0) {

                 //remember to force a scale (with whatever rounding) in your java object to enforce this

                 formatter.setMinimumFractionDigits(number.scale());

             } else {//arbitrary scale

                 //according to the api this line shouldn't be needed for BigDecimal and it should be

                 //able to do arbitrary precision, however it didn't work in my tests it appears there 

                 //is an open java bug that relates to this sun bug (sun BUG:5060859) and that's why

                 //we may need this workaround for now

                 formatter.setMaximumFractionDigits(340);

             }

             string = formatter.format(number);

         }

         catch (IllegalArgumentException e) {

             throw new FormatException("formatting", RiceKeyConstants.ERROR_BIG_DECIMAL, obj.toString(), e);

         }

         catch (ClassCastException e) {

             throw new FormatException("formatting", RiceKeyConstants.ERROR_BIG_DECIMAL, obj.toString(), e);

         }

         return string;

     }

 }