/*
   
   This software is OSI Certified Open Source Software.
   OSI Certified is a certification mark of the Open Source Initiative.
   
   The license (Mozilla version 1.0) can be read at the MMBase site.
   See http://www.MMBase.org/license
   
   */
  package net.sf.mmapps.commons.util;
  
  import java.text.Collator;
  import java.util.*;
  
  
  public class EncodingUtil {
  
      private EncodingUtil() {
          // utility class
      }
      
      private static final String PLAIN_ASCII =
          "AaEeIiOoUu"    // grave
        + "AaEeIiOoUuYy"  // acute
        + "AaEeIiOoUuYy"  // circumflex
        + "AaEeIiOoUuYy"  // tilde
        + "AaEeIiOoUuYy"  // umlaut
        + "Aa"            // ring
        + "Cc"            // cedilla
        ;
  
      private static final String UNICODE =
          "\u00C0\u00E0\u00C8\u00E8\u00CC\u00EC\u00D2\u00F2\u00D9\u00F9"             // grave
        + "\u00C1\u00E1\u00C9\u00E9\u00CD\u00ED\u00D3\u00F3\u00DA\u00FA\u00DD\u00FD" // acute
        + "\u00C2\u00E2\u00CA\u00EA\u00CE\u00EE\u00D4\u00F4\u00DB\u00FB\u0176\u0177" // circumflex
        + "\u00C2\u00E2\u00CA\u00EA\u00CE\u00EE\u00D4\u00F4\u00DB\u00FB\u0176\u0177" // tilde
        + "\u00C4\u00E4\u00CB\u00EB\u00CF\u00EF\u00D6\u00F6\u00DC\u00FC\u0178\u00FF" // umlaut
        + "\u00C5\u00E5"                                                             // ring
        + "\u00C7\u00E7"                                                             // cedilla
        ;
  
        // remove accentued from a string and replace with ascii equivalent
        public static String convertNonAscii(String s) {
           StringBuffer sb = new StringBuffer();
           int n = s.length();
           for (int i = 0; i < n; i++) {
              char c = s.charAt(i);
              int pos = UNICODE.indexOf(c);
              if (pos > -1){
                  sb.append(PLAIN_ASCII.charAt(pos));
              }
              else {
                  sb.append(c);
              }
           }
           return sb.toString();
        }
  
      /***
       * the byte value of a character >= 128 && <= 159 is unused in ISO-8859-1 but it is used by
       * Windows Central Europe encoding, so we can detect it and transcode some of it's
       * characters.
       */
      static Map<Character,String> w1252ToISO;
      static {
          w1252ToISO = new HashMap<Character,String>();
          w1252ToISO.put(new Character('\u0080'), "Euro");
          w1252ToISO.put(new Character('\u0082'), ",");
          w1252ToISO.put(new Character('\u0083'), "f");
          w1252ToISO.put(new Character('\u0085'), "...");
          w1252ToISO.put(new Character('\u0088'), "^");
          w1252ToISO.put(new Character('\u008B'), "<");
          w1252ToISO.put(new Character('\u008C'), "OE");
          w1252ToISO.put(new Character('\u0091'), "'");
          w1252ToISO.put(new Character('\u0092'), "'");
          w1252ToISO.put(new Character('\u0093'), "\"");
          w1252ToISO.put(new Character('\u0094'), "\"");
          w1252ToISO.put(new Character('\u0095'), ".");
          w1252ToISO.put(new Character('\u0096'), "-");
          w1252ToISO.put(new Character('\u0097'), "-");
          w1252ToISO.put(new Character('\u0098'), "~");
          w1252ToISO.put(new Character('\u009B'), ">");
          w1252ToISO.put(new Character('\u009C'), "oe");
      }
  
      public static String windows1252ToISO(String windows1252encoded) {
          StringBuffer transcodedValue = new StringBuffer(windows1252encoded.length());
          for (int i = 0; i < windows1252encoded.length(); i++) {
              char curChar = windows1252encoded.charAt(i);
              if ((curChar >= 128) && (curChar <= 159)) {
                  // this range of characters is unused in ISO-8859-1 but
                  // is used by Windows Central Europe encoding, so we can
                  // detect it and transcode some of it's characters.
                  Character charIndex = new Character(curChar);
                  String replacementStr = w1252ToISO.get(charIndex);
                  if (replacementStr != null) {
                      transcodedValue.append(replacementStr);
                  }
              }
             else {
                 transcodedValue.append(curChar);
             }
         }
         return transcodedValue.toString();
     }
 
     /*** convert from UTF-8 encoded HTML-Pages -> internal Java String Format
      * @param s string to conver
      * @return converted string 
      */
     public static String convertFromUTF8(String s) {
         String out = null;
         try {
             out = new String(s.getBytes("ISO-8859-1"), "UTF-8");
         }
         catch (java.io.UnsupportedEncodingException e) {
             return null;
         }
         return out;
     }
 
     /*** convert from internal Java String Format -> UTF-8 encoded HTML/JSP-Pages
      * @param s string to conver
      * @return converted string 
      */
     public static String convertToUTF8(String s) {
         String out = null;
         try {
             out = new String(s.getBytes("UTF-8"));
         }
         catch (java.io.UnsupportedEncodingException e) {
             return null;
         }
         return out;
     }
     
     public int compareAccentuatedCharacters(String s1, String s2, Locale locale) {
         // (javadoc)
         // The result of String.compareTo() is a negative integer
         // if this String object lexicographically precedes the
         // argument string. The result is a positive integer if
         // this String object lexicographically follows the argument
         // string. The result is zero if the strings are equal;
         // compareTo returns 0 exactly when the equals(Object)
         // method would return true.
 
         // (javadoc)
         // Collator.compare() compares the source string to the target string
         // according to the collation rules for this Collator.
         // Returns an integer less than, equal to or greater than zero
         // depending on whether the source String is less than,
         // equal to or greater than the target string.
         Collator collator = Collator.getInstance(locale);
         collator.setStrength(java.text.Collator.CANONICAL_DECOMPOSITION);
         //  or  collator.setStrength(java.text.Collator.SECONDARY); to be non case sensitive  
         return collator.compare(s1, s2);
     }
 
     public boolean equalAccentuatedCharacters(String s1, String s2, Locale locale) {
         Collator collator = Collator.getInstance(locale);
         collator.setStrength(java.text.Collator.CANONICAL_DECOMPOSITION);
         collator.setStrength(java.text.Collator.SECONDARY); // to be non case sensitive  
         return collator.compare(s1, s2) == 0;
     }
 
 }