/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You under the Apache 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.apache.org/licenses/LICENSE-2.0
   *
   * 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.apache.commons.codec.language;
  
  /**
   * Encodes a string into a Caverphone 2.0 value.
   *
   * This is an algorithm created by the Caversham Project at the University of Otago. It implements the Caverphone 2.0
   * algorithm:
   *
   * @version $Id: Caverphone.java 1075947 2011-03-01 17:56:14Z ggregory $
   * @see <a href="http://en.wikipedia.org/wiki/Caverphone">Wikipedia - Caverphone</a>
   * @see <a href="http://caversham.otago.ac.nz/files/working/ctp150804.pdf">Caverphone 2.0 specification</a>
   * @since 1.5
   *
   * <p>This class is immutable and thread-safe.</p>
   */
  public class Caverphone2 extends AbstractCaverphone {
  
      private static final String TEN_1 = "1111111111";
  
      /**
       * Encodes the given String into a Caverphone 2.0 value.
       *
       * @param source
       *            String the source string
       * @return A caverphone code for the given String
       */
      @Override
      public String encode(final String source) {
          String txt = source;
          if (txt == null || txt.length() == 0) {
              return TEN_1;
          }
  
          // 1. Convert to lowercase
          txt = txt.toLowerCase(java.util.Locale.ENGLISH);
  
          // 2. Remove anything not A-Z
          txt = txt.replaceAll("[^a-z]", "");
  
          // 2.5. Remove final e
          txt = txt.replaceAll("e$", ""); // 2.0 only
  
          // 3. Handle various start options
          txt = txt.replaceAll("^cough", "cou2f");
          txt = txt.replaceAll("^rough", "rou2f");
          txt = txt.replaceAll("^tough", "tou2f");
          txt = txt.replaceAll("^enough", "enou2f"); // 2.0 only
          txt = txt.replaceAll("^trough", "trou2f"); // 2.0 only
                                                     // note the spec says ^enough here again, c+p error I assume
          txt = txt.replaceAll("^gn", "2n");
  
          // End
          txt = txt.replaceAll("mb$", "m2");
  
          // 4. Handle replacements
          txt = txt.replaceAll("cq", "2q");
          txt = txt.replaceAll("ci", "si");
          txt = txt.replaceAll("ce", "se");
          txt = txt.replaceAll("cy", "sy");
          txt = txt.replaceAll("tch", "2ch");
          txt = txt.replaceAll("c", "k");
          txt = txt.replaceAll("q", "k");
          txt = txt.replaceAll("x", "k");
          txt = txt.replaceAll("v", "f");
          txt = txt.replaceAll("dg", "2g");
          txt = txt.replaceAll("tio", "sio");
          txt = txt.replaceAll("tia", "sia");
          txt = txt.replaceAll("d", "t");
          txt = txt.replaceAll("ph", "fh");
          txt = txt.replaceAll("b", "p");
          txt = txt.replaceAll("sh", "s2");
          txt = txt.replaceAll("z", "s");
          txt = txt.replaceAll("^[aeiou]", "A");
          txt = txt.replaceAll("[aeiou]", "3");
          txt = txt.replaceAll("j", "y"); // 2.0 only
          txt = txt.replaceAll("^y3", "Y3"); // 2.0 only
          txt = txt.replaceAll("^y", "A"); // 2.0 only
          txt = txt.replaceAll("y", "3"); // 2.0 only
          txt = txt.replaceAll("3gh3", "3kh3");
          txt = txt.replaceAll("gh", "22");
          txt = txt.replaceAll("g", "k");
          txt = txt.replaceAll("s+", "S");
         txt = txt.replaceAll("t+", "T");
         txt = txt.replaceAll("p+", "P");
         txt = txt.replaceAll("k+", "K");
         txt = txt.replaceAll("f+", "F");
         txt = txt.replaceAll("m+", "M");
         txt = txt.replaceAll("n+", "N");
         txt = txt.replaceAll("w3", "W3");
         txt = txt.replaceAll("wh3", "Wh3");
         txt = txt.replaceAll("w$", "3"); // 2.0 only
         txt = txt.replaceAll("w", "2");
         txt = txt.replaceAll("^h", "A");
         txt = txt.replaceAll("h", "2");
         txt = txt.replaceAll("r3", "R3");
         txt = txt.replaceAll("r$", "3"); // 2.0 only
         txt = txt.replaceAll("r", "2");
         txt = txt.replaceAll("l3", "L3");
         txt = txt.replaceAll("l$", "3"); // 2.0 only
         txt = txt.replaceAll("l", "2");
 
         // 5. Handle removals
         txt = txt.replaceAll("2", "");
         txt = txt.replaceAll("3$", "A"); // 2.0 only
         txt = txt.replaceAll("3", "");
 
         // 6. put ten 1s on the end
         txt = txt + TEN_1;
 
         // 7. take the first ten characters as the code
         return txt.substring(0, TEN_1.length());
     }
 
 }