/**
    * Copyright 2005-2016 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.krad.datadictionary.validation.constraint;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.krad.datadictionary.parse.BeanTagAttribute;
  import org.kuali.rice.krad.uif.UifConstants;
  
  import java.text.DecimalFormat;
  import java.text.NumberFormat;
  import java.util.HashSet;
  
  /**
   * Validation pattern for matching currency type. Extends the FloatingPointPatternConstraint and
   * adds the currency prefix/suffix to the regex string for validation
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  
  public class CurrencyPatternConstraint extends FloatingPointPatternConstraint {
  
      /**
       * @see org.kuali.rice.krad.datadictionary.validation.constraint.ValidCharactersPatternConstraint#getRegexString()
       */
      @Override
      protected String getRegexString() {
          StringBuilder regexString = new StringBuilder(super.getRegexString());
  
          NumberFormat formatter = getCurrencyInstanceUsingParseBigDecimal();
  
          if (!(formatter instanceof DecimalFormat)) {
              return regexString.toString();
          }
  
          String prefix = ((DecimalFormat) formatter).getPositivePrefix();
          String suffix = ((DecimalFormat) formatter).getPositiveSuffix();
  
          // Regex special characters need to be escaped if they are part of the prefix/suffix
          if (prefix != null) {
              StringBuilder escapedPrefix = new StringBuilder();
              for (char c : prefix.toCharArray()) {
                  if (UifConstants.JS_REGEX_SPECIAL_CHARS.indexOf(c) != -1) {
                      escapedPrefix.append("\\");
                  }
                  escapedPrefix.append(c);
              }
  
              regexString.insert(0, "(" + escapedPrefix + ")?");
          }
  
          if (suffix != null) {
              StringBuilder escapedSuffix = new StringBuilder();
              for (char c : suffix.toCharArray()) {
                  if (UifConstants.JS_REGEX_SPECIAL_CHARS.indexOf(c) != -1) {
                      escapedSuffix.append("\\");
                  }
                  escapedSuffix.append(c);
              }
  
              regexString.append("(" + escapedSuffix + ")?");
          }
  
          return regexString.toString();
      }
  
      /**
       * retrieves a currency formatter instance and sets ParseBigDecimal to true
       * to fix [KULEDOCS-742]
       *
       * @return CurrencyInstance
       */
      private NumberFormat getCurrencyInstanceUsingParseBigDecimal() {
          NumberFormat formatter = NumberFormat.getCurrencyInstance();
          if (formatter instanceof DecimalFormat) {
              ((DecimalFormat) formatter).setParseBigDecimal(true);
          }
          return formatter;
      }
  
  }