/*
    * 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.
   */
  package org.apache.maven.doxia.util;
  
  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("max must be a positive integer");
          }
  
          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() {
         if (writer == null) {
             return;
         }
 
         try {
             writer.close();
         } catch (IOException ex) {
             // ignore
         }
     }
 }