package fr.in2p3.jsaga.adaptor.data;
   
   import java.io.UnsupportedEncodingException;
   import java.net.URLEncoder;
   
   /* ***************************************************
    * *** Centre de Calcul de l'IN2P3 - Lyon (France) ***
    * ***             http://cc.in2p3.fr/             ***
    * ***************************************************
   * File:   PathEncoder
   * Author: Sylvain Reynaud (sreynaud@in2p3.fr)
   * Date:   2 oct. 2009
   * ***************************************************
   * Description:                                      */
  /**
   * This is an extract of class fr.in2p3.jsaga.impl.url.URLEncoder in module jsaga-engine
   */
  public class PathEncoder {
      static String encode(String path) throws UnsupportedEncodingException {
          StringBuffer buffer = new StringBuffer();
          char[] array = path.toCharArray();
          for (int i=0; i<array.length; i++) {
              char c = array[i];
              if (c < 128) {      // ASCII
                  if (c=='%' && (isEncodedQuestionMark(array,i) || isEncodedSharp(array,i))) {
                      buffer.append(c);   // allow already encoded '?' or '#'
                  } else if (isIllegalASCII(c)) {
                      appendHex(buffer, c);
                  } else {
                      buffer.append(c);
                  }
              } else {            // non-ASCII (must be converted to UTF-8 before encoding)
                  if (c <= 160) { // isIllegal
                      appendHex(buffer, 0xC0 | (c >> 6));
                      appendHex(buffer, 0x80 | (c & 0x3F));
                  } else {
                      buffer.append(URLEncoder.encode(Character.toString(c), "UTF-8"));
                  }
              }
          }
          return buffer.toString();
      }
      private static boolean isIllegalASCII(char c) {
          if (c <= 32) {
              return true;
          } else {
              switch(c) {
                  // illegal characters
                  case '"': case '%': case '<': case '>': case '[': case '\\': case ']':
                  case '^': case '`': case '{': case '|': case '}': case 127:
                      return true;
                  // reserved characters
                  case '#': case '?':
                      return true;
                  // other characters
                  default:
                      return false;
              }
          }
      }
      private static boolean isEncodedQuestionMark(char[] array, int pos) {
          return pos+2<array.length && array[pos+1]=='3' && array[pos+2]=='F';
      }
      private static boolean isEncodedSharp(char[] array, int pos) {
          return pos+2<array.length && array[pos+1]=='2' && array[pos+2]=='3';
      }
      private static void appendHex(StringBuffer buffer, int c) {
          final char[] HEX = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
          buffer.append('%');
          buffer.append(HEX[c/16]);
          buffer.append(HEX[c%16]);
      }
  }