/*
    * Copyright 2005,2009 Ivan SZKIBA
    *
    * 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.ini4j.spi;
  
  public class WinEscapeTool extends EscapeTool
  {
      private static final int ANSI_HEX_DIGITS = 2;
      private static final int ANSI_OCTAL_DIGITS = 3;
      private static final int OCTAL_RADIX = 8;
      private static final WinEscapeTool INSTANCE = new WinEscapeTool();
  
      public static WinEscapeTool getInstance()
      {
          return INSTANCE;
      }
  
      @Override void escapeBinary(StringBuilder buff, char c)
      {
          buff.append("\\x");
          buff.append(HEX[(c >>> HEX_DIGIT_3_OFFSET) & HEX_DIGIT_MASK]);
          buff.append(HEX[c & HEX_DIGIT_MASK]);
      }
  
      @Override int unescapeBinary(StringBuilder buff, char escapeType, String line, int index)
      {
          int ret = index;
  
          if (escapeType == 'x')
          {
              try
              {
                  buff.append((char) Integer.parseInt(line.substring(index, index + ANSI_HEX_DIGITS), HEX_RADIX));
                  ret = index + ANSI_HEX_DIGITS;
              }
              catch (Exception x)
              {
                  throw new IllegalArgumentException("Malformed \\xHH encoding.", x);
              }
          }
          else if (escapeType == 'o')
          {
              try
              {
                  buff.append((char) Integer.parseInt(line.substring(index, index + ANSI_OCTAL_DIGITS), OCTAL_RADIX));
                  ret = index + ANSI_OCTAL_DIGITS;
              }
              catch (Exception x)
              {
                  throw new IllegalArgumentException("Malformed \\oOO encoding.", x);
              }
          }
  
          return ret;
      }
  }