package org.apache.maven.shared.utils;
   
   /*
    * 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.
   */
  
  import java.util.Locale;
  
  import org.apache.commons.lang3.StringEscapeUtils;
  import org.junit.AfterClass;
  import org.junit.Assert;
  import org.junit.ComparisonFailure;
  import org.junit.Test;
  
  /**
   * Test case for character case changes, to precisely point the situations when character case comparison doesn't
   * give intuitive result, or why one should avoid {@link String#toUpperCase()} and {@link String#toLowerCase()}
   * (platform locale dependent, with sometimes unexpected results)
   * but <b>prefer {@link String#equalsIgnoreCase(String)} when possible</b>.
   * 
   * @author Hervé Boutemy
   * @see <a href="http://sim.ivi.co/2011/07/trap-of-case-insensitive-string.html">Simple Smiles - Xuelei Fan's Blog</a>
   */
  public class CaseTest
      extends Assert
  {
      private final static Locale LOCALE_TURKISH = new Locale( "tr" );
  
      /** common ASCII 'i' */
      private final static char DOTTED_i = '\u0069';
  
      /** common ASCII 'I' */
      private final static char DOTLESS_I = '\u0049';
  
      /** turkish dotless i = ı */
      private final static char DOTLESS_i = '\u0131';
  
      /** turkish dotted I = İ */
      private final static char DOTTED_I = '\u0130';
  
      /** http://en.wikipedia.org/wiki/Dot_(diacritic) */
      private final static char COMBINING_DOT_ABOVE = '\u0307';
  
      private final static Locale SAVED_DEFAULT_LOCALE = Locale.getDefault();
  
      @AfterClass
      public static void restoreDefaultLocale()
      {
          Locale.setDefault( SAVED_DEFAULT_LOCALE );
      }
  
      /**
       * test the known case of upper I which doesn't give commonly expected i in Turkish locale, but ı (dotless i).
       * @see <a href="http://mattryall.net/blog/2009/02/the-infamous-turkish-locale-bug">The infamous Turkish locale bug</a>
       */
      @Test
      public void testTurkishI()
      {
          // check common i and I
          assertEquals( "common lowercase i should have a dot", 'i', DOTTED_i );
          assertEquals( "common uppercase I should not have a dot", 'I', DOTLESS_I );
  
          final String iIıİ = "iIıİ";
  
          // check source encoding doesn't wreck havoc */
          assertUnicodeEquals( "misc i directly in (UTF-8) source", iIıİ, "" + DOTTED_i + DOTLESS_I + DOTLESS_i
              + DOTTED_I );
  
          // check toUpperCase and toLowerCase difference with turkish and english locales
          assertUnicodeEquals( "'iIıİ'.toUpperCase('tr')=='İIIİ'", "" + DOTTED_I + DOTLESS_I + DOTLESS_I + DOTTED_I,
                               iIıİ.toUpperCase( LOCALE_TURKISH ) );
          assertUnicodeEquals( "'iIıİ'.toLowerCase('tr')=='iııi'", "" + DOTTED_i + DOTLESS_i + DOTLESS_i + DOTTED_i,
                               iIıİ.toLowerCase( LOCALE_TURKISH ) );
          assertUnicodeEquals( "'iIıİ'.toUpperCase('en')=='IIIİ'", "" + DOTLESS_I + DOTLESS_I + DOTLESS_I + DOTTED_I,
                               iIıİ.toUpperCase( Locale.ENGLISH ) );
          String lower = iIıİ.toLowerCase( Locale.ENGLISH ); // on some platforms, ends with extra COMBINED DOT ABOVE
          assertUnicodeEquals( "'iIıİ'.toLowerCase('en')=='iiıi'", "" + DOTTED_i + DOTTED_i + DOTLESS_i + DOTTED_i
              + ( lower.length() > 4 ? COMBINING_DOT_ABOVE : "" ), lower );
  
          // check equalsIgnoreCase() , which has no locale
          for ( int i = 0; i < iIıİ.length(); i++ )
          {
              char currentI = iIıİ.charAt( i );
  
             StringBuilder sb = new StringBuilder( iIıİ.length() );
             for ( int j = 0; j < iIıİ.length(); j++ )
             {
                 sb.append( currentI );
             }
             String current = sb.toString();
 
             assertTrue( "'" + current + "'.equalsIgnoreCase('" + iIıİ + "')", current.equalsIgnoreCase( iIıİ ) );
         }
     }
 
     /**
      * Assert equals, and in case the result isn't as expected, display content unicode-escaped.
      * @param message
      * @param expected
      * @param actual
      */
     private void assertUnicodeEquals( String message, String expected, String actual )
     {
         if ( expected.equals( actual ) )
         {
             return;
         }
 
         throw new ComparisonFailure( message, StringEscapeUtils.escapeJava( expected ),
                                      StringEscapeUtils.escapeJava( actual ) );
     }
 
     /**
      * Test case change on all ascii characters with every available locale, to check that turkish i is the only
      * exception on these characters.
      */
     @Test
     public void testAsciiAvailableLocales()
     {
         final String lower = "abcdefghijklmnopqrstuvwxyz";
         final String upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
 
         for ( Locale locale : Locale.getAvailableLocales() )
         {
             // check that toUpper() == toUpper(default locale) and toLower() = toLower(default locale)
             Locale.setDefault( locale );
             assertEquals( lower.toUpperCase(), lower.toUpperCase( locale ) );
             assertEquals( upper.toLowerCase(), upper.toLowerCase( locale ) );
 
             // check result
             String expectedToUpperCase = upper;
             String expectedToLowerCase = lower;
             if ( LOCALE_TURKISH.getLanguage().equals( locale.getLanguage() ) )
             {
                 expectedToUpperCase = upper.replace( DOTLESS_I, DOTTED_I );
                 expectedToLowerCase = lower.replace( DOTTED_i, DOTLESS_i );
             }
 
             assertEquals( "'" + lower + "'.toUpperCase('" + locale.toString() + "')", expectedToUpperCase,
                           lower.toUpperCase( locale ) );
             assertEquals( "'" + upper + "'.toLowerCase('" + locale.toString() + "')", expectedToLowerCase,
                           upper.toLowerCase( locale ) );
 
             // check that toLowerCase on lower and toUpperCase on upper don't cause harm
             assertEquals( "'" + lower + "'.toLowerCase('" + locale.toString() + "')", lower, lower.toLowerCase( locale ) );
             assertEquals( "'" + upper + "'.toUpperCase('" + locale.toString() + "')", upper, upper.toUpperCase( locale ) );
 
             // check equalsIgnoreCase
             assertTrue( "'" + upper + "'.equalsIgnoreCase('" + lower + "')", upper.equalsIgnoreCase( lower ) );
             assertTrue( "'" + upper + "'.equalsIgnoreCase('" + expectedToLowerCase + "')",
                         upper.equalsIgnoreCase( expectedToLowerCase ) );
             assertTrue( "'" + expectedToUpperCase + "'.equalsIgnoreCase('" + lower + "')",
                         expectedToUpperCase.equalsIgnoreCase( lower ) );
         }
     }
 }