package org.apache.maven.doxia.util;
   
   /*
    * 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 org.codehaus.plexus.util.IOUtil;
  
  import java.io.BufferedWriter;
  import java.io.IOException;
  import java.io.Writer;
  
  /**
   * Allows to specify the line-length of an output writer.
   */
  public class LineBreaker
  {
      /** The default maximal line length. */
      public static final int DEFAULT_MAX_LINE_LENGTH = 78;
  
      /** The system dependent EOL. */
      private static final String EOL = System.getProperty( "line.separator" );
  
      /** The destination writer. */
      private Writer destination;
  
      /** The writer to use. */
      private BufferedWriter writer;
  
      /** The maximal line length. */
      private int maxLineLength;
  
      /** The current line length. */
      private int lineLength = 0;
  
      /** The string buffer to store the current text. */
      private StringBuilder word = new StringBuilder( 1024 );
  
      /**
       * Constructs a new LineBreaker with DEFAULT_MAX_LINE_LENGTH.
       *
       * @param out The writer to use.
       */
      public LineBreaker( Writer out )
      {
          this( out, DEFAULT_MAX_LINE_LENGTH );
      }
  
      /**
       * Constructs a new LineBreaker with the given max line length.
       *
       * @param out The writer to use.
       * @param max The maximal line length.
       */
      public LineBreaker( Writer out, int max )
      {
          if ( max <= 0 )
          {
              throw new IllegalArgumentException( "maxLineLength <= 0" );
          }
  
          destination = out;
          this.maxLineLength = max;
          writer = new BufferedWriter( out );
      }
  
      /**
       * Returns the current destination writer.
       *
       * @return The destination.
       */
      public Writer getDestination()
      {
          return destination;
      }
  
      /**
       * Writes the given text to the writer. White space is not preserved.
       *
       * @param text The text to write.
       * @throws java.io.IOException if there's a problem writing the text.
       */
      public void write( String text )
          throws IOException
     {
         write( text, /*preserveSpace*/false );
     }
 
     /**
      * Writes the given text to the writer.
      *
      * @param text The text to write.
      * @param preserveSpace True to preserve white space.
      */
     public void write( String text, boolean preserveSpace )
     {
         int length = text.length();
 
         try
         {
             for ( int i = 0; i < length; ++i )
             {
                 char c = text.charAt( i );
 
                 switch ( c )
                 {
                     case ' ':
                         if ( preserveSpace )
                         {
                             word.append( c );
                         }
                         else
                         {
                             writeWord();
                         }
                         break;
 
                     case '\r':
                         // if \r\n (windows) then just pass along \n
                         if ( i + 1 < length && text.charAt( i + 1 ) == '\n' )
                         {
                             break;
                         }
 
                     case '\n':
                         writeWord();
                         writer.write( EOL );
                         lineLength = 0;
                         break;
 
                     default:
                         word.append( c );
                 }
 
             }
         }
         catch ( Exception e )
         {
             // TODO: log
         }
     }
 
     /**
      * Write out the current StringBuilder and flush the writer.
      * Any IOException will be swallowed.
      */
     public void flush()
     {
         try
         {
             writeWord();
             writer.flush();
         }
         catch ( IOException e )
         {
             // TODO: log
         }
     }
 
     /**
      * Writes the current StringBuilder to the writer.
      *
      * @throws IOException if an exception occurs during writing.
      */
     private void writeWord()
         throws IOException
     {
         int length = word.length();
         if ( length > 0 )
         {
             if ( lineLength > 0 )
             {
                 if ( lineLength + 1 + length > maxLineLength )
                 {
                     writer.write( EOL );
                     lineLength = 0;
                 }
                 else
                 {
                     writer.write( ' ' );
                     ++lineLength;
                 }
             }
 
             writer.write( word.toString() );
             word.setLength( 0 );
 
             lineLength += length;
         }
     }
 
     /**
      * Close the writer.
      */
     public void close()
     {
         IOUtil.close( writer );
     }
 }