package org.apache.maven.shared.utils.io;
   
   /*
    * 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.io.File;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.StringTokenizer;
  
  import javax.annotation.Nonnull;
  
  /**
   * <p>This is a utility class used by selectors and DirectoryScanner. The
   * functionality more properly belongs just to selectors, but unfortunately
   * DirectoryScanner exposed these as protected methods. Thus we have to
   * support any subclasses of DirectoryScanner that may access these methods.
   * </p>
   * <p>This is a Singleton.</p>
   *
   * @author Arnout J. Kuiper
   *         <a href="mailto:ajkuiper@wxs.nl">ajkuiper@wxs.nl</a>
   * @author Magesh Umasankar
   * @author <a href="mailto:bruce@callenish.com">Bruce Atherton</a>
   * 
   */
  public final class SelectorUtils
  {
  
      private static final String PATTERN_HANDLER_PREFIX = "[";
  
      public static final String PATTERN_HANDLER_SUFFIX = "]";
  
      public static final String REGEX_HANDLER_PREFIX = "%regex" + PATTERN_HANDLER_PREFIX;
  
      public static final String ANT_HANDLER_PREFIX = "%ant" + PATTERN_HANDLER_PREFIX;
  
      /**
       * Private Constructor
       */
      private SelectorUtils()
      {
      }
  
      /**
       * Tests whether or not a given path matches the start of a given
       * pattern up to the first "**".
       * <p/>
       * This is not a general purpose test and should only be used if you
       * can live with false positives. For example, <code>pattern=**\a</code>
       * and <code>str=b</code> will yield <code>true</code>.
       *
       * @param pattern The pattern to match against. Must not be
       *                <code>null</code>.
       * @param str     The path to match, as a String. Must not be
       *                <code>null</code>.
       * @return whether or not a given path matches the start of a given
       *         pattern up to the first "**".
       */
      public static boolean matchPatternStart( String pattern, String str )
      {
          return matchPatternStart( pattern, str, true );
      }
  
      /**
       * Tests whether or not a given path matches the start of a given
       * pattern up to the first "**".
       * <p/>
       * This is not a general purpose test and should only be used if you
       * can live with false positives. For example, <code>pattern=**\a</code>
       * and <code>str=b</code> will yield <code>true</code>.
       *
       * @param pattern         The pattern to match against. Must not be
       *                        <code>null</code>.
       * @param str             The path to match, as a String. Must not be
       *                        <code>null</code>.
       * @param isCaseSensitive Whether or not matching should be performed
       *                        case sensitively.
       * @return whether or not a given path matches the start of a given
       *         pattern up to the first "**".
       */
      public static boolean matchPatternStart( String pattern, String str, boolean isCaseSensitive )
      {
         if ( isRegexPrefixedPattern( pattern ) )
         {
             // FIXME: ICK! But we can't do partial matches for regex, so we have to reserve judgement until we have
             // a file to deal with, or we can definitely say this is an exclusion...
             return true;
         }
         else
         {
             if ( isAntPrefixedPattern( pattern ) )
             {
                 pattern = pattern.substring( ANT_HANDLER_PREFIX.length(),
                                              pattern.length() - PATTERN_HANDLER_SUFFIX.length() );
             }
 
             String altPattern = pattern.replace( '\\', '/' );
             String altStr = str.replace( '\\', '/' );
 
             return matchAntPathPatternStart( altPattern, altStr, "/", isCaseSensitive );
         }
     }
 
     private static boolean matchAntPathPatternStart( String pattern, String str, String separator,
                                                      boolean isCaseSensitive )
     {
         // When str starts with a File.separator, pattern has to start with a
         // File.separator.
         // When pattern starts with a File.separator, str has to start with a
         // File.separator.
         if ( separatorPatternStartSlashMismatch( pattern, str, separator ) )
         {
             return false;
         }
 
         List<String> patDirs = tokenizePath( pattern, separator );
         List<String> strDirs = tokenizePath( str, separator );
 
         int patIdxStart = 0;
         int patIdxEnd = patDirs.size() - 1;
         int strIdxStart = 0;
         int strIdxEnd = strDirs.size() - 1;
 
         // up to first '**'
         while ( patIdxStart <= patIdxEnd && strIdxStart <= strIdxEnd )
         {
             String patDir = patDirs.get( patIdxStart );
             if ( "**".equals( patDir ) )
             {
                 break;
             }
             if ( !match( patDir, strDirs.get( strIdxStart ), isCaseSensitive ) )
             {
                 return false;
             }
             patIdxStart++;
             strIdxStart++;
         }
 
         return strIdxStart > strIdxEnd || patIdxStart <= patIdxEnd;
     }
 
     /**
      * Tests whether or not a given path matches a given pattern.
      *
      * @param pattern The pattern to match against. Must not be
      *                <code>null</code>.
      * @param str     The path to match, as a String. Must not be
      *                <code>null</code>.
      * @return <code>true</code> if the pattern matches against the string,
      *         or <code>false</code> otherwise.
      */
     public static boolean matchPath( String pattern, String str )
     {
         return matchPath( pattern, str, true );
     }
 
     /**
      * Tests whether or not a given path matches a given pattern.
      *
      * @param pattern         The pattern to match against. Must not be
      *                        <code>null</code>.
      * @param str             The path to match, as a String. Must not be
      *                        <code>null</code>.
      * @param isCaseSensitive Whether or not matching should be performed
      *                        case sensitively.
      * @return <code>true</code> if the pattern matches against the string,
      *         or <code>false</code> otherwise.
      */
     public static boolean matchPath( String pattern, String str, boolean isCaseSensitive )
     {
         if ( pattern.length() > ( REGEX_HANDLER_PREFIX.length() + PATTERN_HANDLER_SUFFIX.length() + 1 )
             && pattern.startsWith( REGEX_HANDLER_PREFIX ) && pattern.endsWith( PATTERN_HANDLER_SUFFIX ) )
         {
             pattern =
                 pattern.substring( REGEX_HANDLER_PREFIX.length(), pattern.length() - PATTERN_HANDLER_SUFFIX.length() );
 
             return str.matches( pattern );
         }
         else
         {
             if ( pattern.length() > ( ANT_HANDLER_PREFIX.length() + PATTERN_HANDLER_SUFFIX.length() + 1 )
                 && pattern.startsWith( ANT_HANDLER_PREFIX ) && pattern.endsWith( PATTERN_HANDLER_SUFFIX ) )
             {
                 pattern = pattern.substring( ANT_HANDLER_PREFIX.length(),
                                              pattern.length() - PATTERN_HANDLER_SUFFIX.length() );
             }
 
             return matchAntPathPattern( pattern, str, isCaseSensitive );
         }
     }
 
     private static boolean matchAntPathPattern( String pattern, String str, boolean isCaseSensitive )
     {
         // When str starts with a File.separator, pattern has to start with a
         // File.separator.
         // When pattern starts with a File.separator, str has to start with a
         // File.separator.
         if ( str.startsWith( File.separator ) != pattern.startsWith( File.separator ) )
         {
             return false;
         }
 
         List<String> patDirs = tokenizePath( pattern, File.separator );
         List<String> strDirs = tokenizePath( str, File.separator );
 
         int patIdxStart = 0;
         int patIdxEnd = patDirs.size() - 1;
         int strIdxStart = 0;
         int strIdxEnd = strDirs.size() - 1;
 
         // up to first '**'
         while ( patIdxStart <= patIdxEnd && strIdxStart <= strIdxEnd )
         {
             String patDir = patDirs.get( patIdxStart );
             if ( "**".equals( patDir ) )
             {
                 break;
             }
             if ( !match( patDir, strDirs.get( strIdxStart ), isCaseSensitive ) )
             {
                 return false;
             }
             patIdxStart++;
             strIdxStart++;
         }
         if ( strIdxStart > strIdxEnd )
         {
             // String is exhausted
             for ( int i = patIdxStart; i <= patIdxEnd; i++ )
             {
                 if ( !"**".equals( patDirs.get( i ) ) )
                 {
                     return false;
                 }
             }
             return true;
         }
         else
         {
             if ( patIdxStart > patIdxEnd )
             {
                 // String not exhausted, but pattern is. Failure.
                 return false;
             }
         }
 
         // up to last '**'
         while ( patIdxStart <= patIdxEnd && strIdxStart <= strIdxEnd )
         {
             String patDir = patDirs.get( patIdxEnd );
             if ( "**".equals( patDir ) )
             {
                 break;
             }
             if ( !match( patDir, strDirs.get( strIdxEnd ), isCaseSensitive ) )
             {
                 return false;
             }
             patIdxEnd--;
             strIdxEnd--;
         }
         if ( strIdxStart > strIdxEnd )
         {
             // String is exhausted
             for ( int i = patIdxStart; i <= patIdxEnd; i++ )
             {
                 if ( !"**".equals( patDirs.get( i ) ) )
                 {
                     return false;
                 }
             }
             return true;
         }
 
         while ( patIdxStart != patIdxEnd && strIdxStart <= strIdxEnd )
         {
             int patIdxTmp = -1;
             for ( int i = patIdxStart + 1; i <= patIdxEnd; i++ )
             {
                 if ( "**".equals( patDirs.get( i ) ) )
                 {
                     patIdxTmp = i;
                     break;
                 }
             }
             if ( patIdxTmp == patIdxStart + 1 )
             {
                 // '**/**' situation, so skip one
                 patIdxStart++;
                 continue;
             }
             // Find the pattern between padIdxStart & padIdxTmp in str between
             // strIdxStart & strIdxEnd
             int patLength = ( patIdxTmp - patIdxStart - 1 );
             int strLength = ( strIdxEnd - strIdxStart + 1 );
             int foundIdx = -1;
             strLoop:
             for ( int i = 0; i <= strLength - patLength; i++ )
             {
                 for ( int j = 0; j < patLength; j++ )
                 {
                     String subPat = patDirs.get( patIdxStart + j + 1 );
                     String subStr = strDirs.get( strIdxStart + i + j );
                     if ( !match( subPat, subStr, isCaseSensitive ) )
                     {
                         continue strLoop;
                     }
                 }
 
                 foundIdx = strIdxStart + i;
                 break;
             }
 
             if ( foundIdx == -1 )
             {
                 return false;
             }
 
             patIdxStart = patIdxTmp;
             strIdxStart = foundIdx + patLength;
         }
 
         for ( int i = patIdxStart; i <= patIdxEnd; i++ )
         {
             if ( !"**".equals( patDirs.get( i ) ) )
             {
                 return false;
             }
         }
 
         return true;
     }
 
     /**
      * Tests whether or not a string matches against a pattern.
      * The pattern may contain two special characters:<br>
      * '*' means zero or more characters<br>
      * '?' means one and only one character
      *
      * @param pattern The pattern to match against.
      *                Must not be <code>null</code>.
      * @param str     The string which must be matched against the pattern.
      *                Must not be <code>null</code>.
      * @return <code>true</code> if the string matches against the pattern,
      *         or <code>false</code> otherwise.
      */
     public static boolean match( String pattern, String str )
     {
         return match( pattern, str, true );
     }
 
     /**
      * Tests whether or not a string matches against a pattern.
      * The pattern may contain two special characters:<br>
      * '*' means zero or more characters<br>
      * '?' means one and only one character
      *
      * @param pattern         The pattern to match against.
      *                        Must not be <code>null</code>.
      * @param str             The string which must be matched against the pattern.
      *                        Must not be <code>null</code>.
      * @param isCaseSensitive Whether or not matching should be performed
      *                        case sensitively.
      * @return <code>true</code> if the string matches against the pattern,
      *         or <code>false</code> otherwise.
      */
     public static boolean match( String pattern, String str, boolean isCaseSensitive )
     {
         char[] patArr = pattern.toCharArray();
         char[] strArr = str.toCharArray();
         int patIdxStart = 0;
         int patIdxEnd = patArr.length - 1;
         int strIdxStart = 0;
         int strIdxEnd = strArr.length - 1;
         char ch;
 
         boolean containsStar = false;
         for ( char aPatArr : patArr )
         {
             if ( aPatArr == '*' )
             {
                 containsStar = true;
                 break;
             }
         }
 
         if ( !containsStar )
         {
             // No '*'s, so we make a shortcut
             if ( patIdxEnd != strIdxEnd )
             {
                 return false; // Pattern and string do not have the same size
             }
             for ( int i = 0; i <= patIdxEnd; i++ )
             {
                 ch = patArr[i];
                 if ( ch != '?' && !equals( ch, strArr[i], isCaseSensitive ) )
                 {
                     return false; // Character mismatch
                 }
             }
             return true; // String matches against pattern
         }
 
         if ( patIdxEnd == 0 )
         {
             return true; // Pattern contains only '*', which matches anything
         }
 
         // Process characters before first star
         // CHECKSTYLE_OFF: InnerAssignment
         while ( ( ch = patArr[patIdxStart] ) != '*' && strIdxStart <= strIdxEnd )
         // CHECKSTYLE_ON: InnerAssignment
         {
             if ( ch != '?' && !equals( ch, strArr[strIdxStart], isCaseSensitive ) )
             {
                 return false; // Character mismatch
             }
             patIdxStart++;
             strIdxStart++;
         }
         if ( strIdxStart > strIdxEnd )
         {
             // All characters in the string are used. Check if only '*'s are
             // left in the pattern. If so, we succeeded. Otherwise failure.
             for ( int i = patIdxStart; i <= patIdxEnd; i++ )
             {
                 if ( patArr[i] != '*' )
                 {
                     return false;
                 }
             }
             return true;
         }
 
         // Process characters after last star
         // CHECKSTYLE_OFF: InnerAssignment
         while ( ( ch = patArr[patIdxEnd] ) != '*' && strIdxStart <= strIdxEnd )
         // CHECKSTYLE_ON: InnerAssignment
         {
             if ( ch != '?' && !equals( ch, strArr[strIdxEnd], isCaseSensitive ) )
             {
                 return false; // Character mismatch
             }
             patIdxEnd--;
             strIdxEnd--;
         }
         if ( strIdxStart > strIdxEnd )
         {
             // All characters in the string are used. Check if only '*'s are
             // left in the pattern. If so, we succeeded. Otherwise failure.
             for ( int i = patIdxStart; i <= patIdxEnd; i++ )
             {
                 if ( patArr[i] != '*' )
                 {
                     return false;
                 }
             }
             return true;
         }
 
         // process pattern between stars. padIdxStart and patIdxEnd point
         // always to a '*'.
         while ( patIdxStart != patIdxEnd && strIdxStart <= strIdxEnd )
         {
             int patIdxTmp = -1;
             for ( int i = patIdxStart + 1; i <= patIdxEnd; i++ )
             {
                 if ( patArr[i] == '*' )
                 {
                     patIdxTmp = i;
                     break;
                 }
             }
             if ( patIdxTmp == patIdxStart + 1 )
             {
                 // Two stars next to each other, skip the first one.
                 patIdxStart++;
                 continue;
             }
             // Find the pattern between padIdxStart & padIdxTmp in str between
             // strIdxStart & strIdxEnd
             int patLength = ( patIdxTmp - patIdxStart - 1 );
             int strLength = ( strIdxEnd - strIdxStart + 1 );
             int foundIdx = -1;
             strLoop:
             for ( int i = 0; i <= strLength - patLength; i++ )
             {
                 for ( int j = 0; j < patLength; j++ )
                 {
                     ch = patArr[patIdxStart + j + 1];
                     if ( ch != '?' && !equals( ch, strArr[strIdxStart + i + j], isCaseSensitive ) )
                     {
                         continue strLoop;
                     }
                 }
 
                 foundIdx = strIdxStart + i;
                 break;
             }
 
             if ( foundIdx == -1 )
             {
                 return false;
             }
 
             patIdxStart = patIdxTmp;
             strIdxStart = foundIdx + patLength;
         }
 
         // All characters in the string are used. Check if only '*'s are left
         // in the pattern. If so, we succeeded. Otherwise failure.
         for ( int i = patIdxStart; i <= patIdxEnd; i++ )
         {
             if ( patArr[i] != '*' )
             {
                 return false;
             }
         }
         return true;
     }
 
     /**
      * Tests whether two characters are equal.
      */
     private static boolean equals( char c1, char c2, boolean isCaseSensitive )
     {
         if ( c1 == c2 )
         {
             return true;
         }
         if ( !isCaseSensitive )
         {
             // NOTE: Try both upper case and lower case as done by String.equalsIgnoreCase()
             if ( Character.toUpperCase( c1 ) == Character.toUpperCase( c2 )
                 || Character.toLowerCase( c1 ) == Character.toLowerCase( c2 ) )
             {
                 return true;
             }
         }
         return false;
     }
 
     /**
      * Breaks a path up into a List of path elements, tokenizing on
      * <code>File.separator</code>.
      *
      * @param path Path to tokenize. Must not be <code>null</code>.
      * @param separator The separator to use
      * @return a List of path elements from the tokenized path
      */
     private static List<String> tokenizePath( String path, String separator )
     {
         List<String> ret = new ArrayList<String>();
         StringTokenizer st = new StringTokenizer( path, separator );
         while ( st.hasMoreTokens() )
         {
             ret.add( st.nextToken() );
         }
         return ret;
     }
 
 
     static boolean matchAntPathPatternStart( @Nonnull MatchPattern pattern,
                                              @Nonnull String str,
                                              @Nonnull String separator,
                                              boolean isCaseSensitive )
     {
         return !separatorPatternStartSlashMismatch( pattern, str, separator )
             && matchAntPathPatternStart( pattern.getTokenizedPathString(), str, separator, isCaseSensitive );
     }
 
     private static String[] tokenizePathToString( @Nonnull String path, @Nonnull String separator )
     {
         List<String> ret = new ArrayList<String>();
         StringTokenizer st = new StringTokenizer( path, separator );
         while ( st.hasMoreTokens() )
         {
             ret.add( st.nextToken() );
         }
         return ret.toArray( new String[ret.size()] );
     }
 
     private static boolean matchAntPathPatternStart( @Nonnull String[] patDirs,
                                                      @Nonnull String str,
                                                      @Nonnull  String separator,
                                                      boolean isCaseSensitive )
     {
         String[] strDirs = tokenizePathToString( str, separator );
         return matchAntPathPatternStart( patDirs, strDirs, isCaseSensitive );
     }
 
     private static boolean matchAntPathPatternStart( @Nonnull String[] patDirs,
                                                      @Nonnull String[] tokenizedFileName,
                                                      boolean isCaseSensitive )
     {
 
         int patIdxStart = 0;
         int patIdxEnd = patDirs.length - 1;
         int strIdxStart = 0;
         int strIdxEnd = tokenizedFileName.length - 1;
 
         // up to first '**'
         while ( patIdxStart <= patIdxEnd && strIdxStart <= strIdxEnd )
         {
             String patDir = patDirs[patIdxStart];
             if ( patDir.equals( "**" ) )
             {
                 break;
             }
             if ( !match( patDir, tokenizedFileName[strIdxStart], isCaseSensitive ) )
             {
                 return false;
             }
             patIdxStart++;
             strIdxStart++;
         }
 
         return strIdxStart > strIdxEnd || patIdxStart <= patIdxEnd;
     }
 
     private static boolean separatorPatternStartSlashMismatch( @Nonnull MatchPattern matchPattern, @Nonnull String str,
                                                                @Nonnull String separator )
     {
         return str.startsWith( separator ) != matchPattern.startsWith( separator );
     }
 
     private static boolean separatorPatternStartSlashMismatch( String pattern, String str, String separator )
     {
         return str.startsWith( separator ) != pattern.startsWith( separator );
     }
 
 
     static boolean matchAntPathPattern( String[] patDirs, String[] strDirs, boolean isCaseSensitive )
     {
         int patIdxStart = 0;
         int patIdxEnd = patDirs.length - 1;
         int strIdxStart = 0;
         int strIdxEnd = strDirs.length - 1;
 
         // up to first '**'
         while ( patIdxStart <= patIdxEnd && strIdxStart <= strIdxEnd )
         {
             String patDir = patDirs[patIdxStart];
             if ( patDir.equals( "**" ) )
             {
                 break;
             }
             if ( !match( patDir, strDirs[strIdxStart], isCaseSensitive ) )
             {
                 return false;
             }
             patIdxStart++;
             strIdxStart++;
         }
         if ( strIdxStart > strIdxEnd )
         {
             // String is exhausted
             for ( int i = patIdxStart; i <= patIdxEnd; i++ )
             {
                 if ( !patDirs[i].equals( "**" ) )
                 {
                     return false;
                 }
             }
             return true;
         }
         else
         {
             if ( patIdxStart > patIdxEnd )
             {
                 // String not exhausted, but pattern is. Failure.
                 return false;
             }
         }
 
         // up to last '**'
         while ( patIdxStart <= patIdxEnd && strIdxStart <= strIdxEnd )
         {
             String patDir = patDirs[patIdxEnd];
             if ( patDir.equals( "**" ) )
             {
                 break;
             }
             if ( !match( patDir, strDirs[strIdxEnd], isCaseSensitive ) )
             {
                 return false;
             }
             patIdxEnd--;
             strIdxEnd--;
         }
         if ( strIdxStart > strIdxEnd )
         {
             // String is exhausted
             for ( int i = patIdxStart; i <= patIdxEnd; i++ )
             {
                 if ( !patDirs[i].equals( "**" ) )
                 {
                     return false;
                 }
             }
             return true;
         }
 
         while ( patIdxStart != patIdxEnd && strIdxStart <= strIdxEnd )
         {
             int patIdxTmp = -1;
             for ( int i = patIdxStart + 1; i <= patIdxEnd; i++ )
             {
                 if ( patDirs[i].equals( "**" ) )
                 {
                     patIdxTmp = i;
                     break;
                 }
             }
             if ( patIdxTmp == patIdxStart + 1 )
             {
                 // '**/**' situation, so skip one
                 patIdxStart++;
                 continue;
             }
             // Find the pattern between padIdxStart & padIdxTmp in str between
             // strIdxStart & strIdxEnd
             int patLength = ( patIdxTmp - patIdxStart - 1 );
             int strLength = ( strIdxEnd - strIdxStart + 1 );
             int foundIdx = -1;
             strLoop:
             for ( int i = 0; i <= strLength - patLength; i++ )
             {
                 for ( int j = 0; j < patLength; j++ )
                 {
                     String subPat = patDirs[patIdxStart + j + 1];
                     String subStr = strDirs[strIdxStart + i + j];
                     if ( !match( subPat, subStr, isCaseSensitive ) )
                     {
                         continue strLoop;
                     }
                 }
 
                 foundIdx = strIdxStart + i;
                 break;
             }
 
             if ( foundIdx == -1 )
             {
                 return false;
             }
 
             patIdxStart = patIdxTmp;
             strIdxStart = foundIdx + patLength;
         }
 
         for ( int i = patIdxStart; i <= patIdxEnd; i++ )
         {
             if ( !patDirs[i].equals( "**" ) )
             {
                 return false;
             }
         }
 
         return true;
     }
 
     static boolean isRegexPrefixedPattern( String pattern )
     {
         return pattern.length() > ( REGEX_HANDLER_PREFIX.length() + PATTERN_HANDLER_SUFFIX.length() + 1 )
             && pattern.startsWith( REGEX_HANDLER_PREFIX ) && pattern.endsWith( PATTERN_HANDLER_SUFFIX );
     }
 
     static boolean isAntPrefixedPattern( String pattern )
     {
         return pattern.length() > ( ANT_HANDLER_PREFIX.length() + PATTERN_HANDLER_SUFFIX.length() + 1 )
             && pattern.startsWith( ANT_HANDLER_PREFIX ) && pattern.endsWith( PATTERN_HANDLER_SUFFIX );
     }
 
     static boolean matchAntPathPattern( @Nonnull MatchPattern matchPattern, @Nonnull String str,
                                         @Nonnull String separator, boolean isCaseSensitive )
     {
         if ( separatorPatternStartSlashMismatch( matchPattern, str, separator ) )
         {
             return false;
         }
         String[] patDirs = matchPattern.getTokenizedPathString();
         String[] strDirs = tokenizePathToString( str, separator );
         return matchAntPathPattern( patDirs, strDirs, isCaseSensitive );
     }
 }