content: /**
   * Copyright 2009 Alexander Kuznetsov 
   *
   * Licensed 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.lucene.morphology.russian;
  
  import org.apache.lucene.morphology.LetterDecoderEncoder;
  import org.apache.lucene.morphology.SuffixToLongException;
  import org.apache.lucene.morphology.WrongCharaterException;
  
  import java.util.LinkedList;
  
  /**
   * This helper class allow encode suffix of russian word
   * to long value and decode from it.
   * Assumed that suffix contains only small russian letters and dash.
   * Also assumed that letter � and � coinsed.
   */
  public class RussianLetterDecoderEncoder implements LetterDecoderEncoder {
      public static final int RUSSIAN_SMALL_LETTER_OFFSET = 1071;
      public static final int WORD_PART_LENGHT = 6;
      public static final int EE_CHAR = 34;
      public static final int E_CHAR = 6;
      public static final int DASH_CHAR = 45;
      public static final int DASH_CODE = 33;
  
      public Integer encode(String string) {
          if (string.length() > WORD_PART_LENGHT)
              throw new SuffixToLongException("Suffix length should not be greater then " + WORD_PART_LENGHT + " " + string);
          int result = 0;
          for (int i = 0; i < string.length(); i++) {
              int c = string.charAt(i) - RUSSIAN_SMALL_LETTER_OFFSET;
              if (c == 45 - RUSSIAN_SMALL_LETTER_OFFSET) {
                  c = DASH_CODE;
              }
              if (c == EE_CHAR) c = E_CHAR;
              if (c < 0 || c > 33)
                  throw new WrongCharaterException("Symbol " + string.charAt(i) + " is not small cirillic letter");
              result = result * 34 + c;
          }
          for (int i = string.length(); i < WORD_PART_LENGHT; i++) {
              result *= 34;
          }
          return result;
      }
  
      public int[] encodeToArray(String s) {
          LinkedList<Integer> integers = new LinkedList<>();
          while (s.length() > WORD_PART_LENGHT) {
              integers.add(encode(s.substring(0, WORD_PART_LENGHT)));
              s = s.substring(WORD_PART_LENGHT);
          }
          integers.add(encode(s));
          int[] ints = new int[integers.size()];
          int pos = 0;
          for (Integer i : integers) {
              ints[pos] = i;
              pos++;
          }
          return ints;
      }
  
      public String decodeArray(int[] array) {
          StringBuilder result = new StringBuilder();
          for (int i : array) {
              result.append(decode(i));
          }
          return result.toString();
      }
  
  
      public String decode(Integer suffixN) {
          StringBuilder result = new StringBuilder();
          while (suffixN > 33) {
              int c = suffixN % 34 + RUSSIAN_SMALL_LETTER_OFFSET;
              if (c == RUSSIAN_SMALL_LETTER_OFFSET) {
                  suffixN /= 34;
                  continue;
              }
              if (c == DASH_CODE + RUSSIAN_SMALL_LETTER_OFFSET) c = DASH_CHAR;
              result.insert(0, (char) c);
              suffixN /= 34;
          }
          long c = suffixN + RUSSIAN_SMALL_LETTER_OFFSET;
          if (c == DASH_CODE + RUSSIAN_SMALL_LETTER_OFFSET) c = DASH_CHAR;
          result.insert(0, (char) c);
          return result.toString();
      }
  
      public boolean checkCharacter(char c) {
          int code = c;
          if (code == 45) return true;
          code -= RUSSIAN_SMALL_LETTER_OFFSET;
          return code > 0 && code < 33;
      }
  
      public boolean checkString(String word) {
          for (int i = 0; i < word.length(); i++) {
              if (!checkCharacter(word.charAt(i))) {
                  return false;
              }
          }
          return true;
      }
  
      public String cleanString(String s) {
          return s.replace((char) (EE_CHAR + RussianLetterDecoderEncoder.RUSSIAN_SMALL_LETTER_OFFSET), (char) (E_CHAR + RussianLetterDecoderEncoder.RUSSIAN_SMALL_LETTER_OFFSET));
      }
  }
  