package org.paneris.bibliomania.fti;

 import java.io.BufferedInputStream;

 import java.io.File;

 import java.io.FileInputStream;

 import java.io.IOException;

 import java.io.InputStream;

 import org.melati.poem.NoSuchRowPoemException;

 import com.sleepycat.db.DatabaseException;

 public class ContextSearchResults implements SearchResults {

   private static byte[] skipBuffer = new byte[5000];

   public static final String contextUnavailable = "(context not available)";

   public static final int contextWordsAfterHit = 5;

   public static final int wordsGapBetweenAreas = 6;

   private Library library;

   private Text currentText = null;

   private SearchResults results;

   private AnchorFinder blockmarks;

   // we don't want to use a Reader for this because then skip is implemented

   // using repeated reads ...

   private InputStream body = null;

   private long bodyPosition;

   public ContextSearchResults(Library library, SearchResults results,

       IndexOther fti) {

     this.library = library;

     this.results = results;

     blockmarks = new AnchorFinder(fti, true);

   }

   public int frequency() {

     return results.frequency();

   }

   public int hitWordsCount() {

     return results.hitWordsCount();

   }

   public void init() {

     closeBody();

     results.init();

   }

   public void skipToNextHit() {

     results.skipToNextHit();

   }

   public void skipToWordIndex(int wordIndex) {

     results.skipToWordIndex(wordIndex);

   }

   public int currentWordIndex() {

     return results.currentWordIndex();

   }

   public int currentOffset() {

     return results.currentOffset();

   }

   public void gotoText(long textID) throws DatabaseException {

     closeBody();

     results.gotoText(textID);

     long it = results.currentTextID();

     currentText = it == -1 ? null : library.text(it);

   }

   public void gotoPosition(long position) throws DatabaseException {

     gotoText(position >> 32);

     if (currentTextID() != -1)

       skipToWordIndex((int) position);

   }

   public long getPosition() {

     int wi = currentWordIndex();

     return wi == -1 ? -1 : (currentTextID() << 32 | wi);

   }

   public long currentTextID() {

     return results.currentTextID();

   }

   public Text currentText() {

     return currentText;

   }

   public String currentAnchor() throws DatabaseException {

     // FIXME not necessarily very optimal

     // could exploit forward-moving definition of these cursors

     int index = currentWordIndex();

     return index == -1 ? null : blockmarks

         .anchorOfIndex(currentTextID(), index);

   }

   private synchronized void closeBody() {

     if (body != null) {

       try {

         body.close();

       } catch (IOException e) {

       }

       body = null;

     }

   }

   public synchronized String nextArea() {

     try {

       long target = results.currentOffset();

       if (target == -1) {

         closeBody();

         return null;

       }

       if (body == null) {

         if (currentText == null)

           return null;

         try { 

           body = new BufferedInputStream(currentText.bodyForFragment());

           bodyPosition = 0;

         } catch (NoSuchRowPoemException e) { 

           // This should not happen in a coherent database, but 

           // the one on my machine isn't coherent

           return null;

         }

       }

       if (bodyPosition > target)

         throw new IOException("tried to skip backwards");

       // FIXME BufferedInputStream seems genuinely not to work well

       // wrt to skipping ... so we use skip for the first move and dummy

       // reads thereafter

       if (bodyPosition == 0)

         bodyPosition += body.skip(target - bodyPosition);

       else {

         long read;

         do {

           bodyPosition += (read = body.read(skipBuffer, 0, (int) Math.min(

               target - bodyPosition, skipBuffer.length)));

         } while (read > 0);

       }

       if (bodyPosition < target)

         throw new IOException("skipped only to " + bodyPosition + " not "

             + target);

       StringBuffer buf = new StringBuffer();

       IndexTokenizer words = new IndexTokenizer(body, true);

       int baseIndex = Math.max(results.currentWordIndex()

           - IndexOther.contextWordsBeforeHit, 0);

       // int lastIndex = -1;

       do {

         int limitIndex = results.currentWordIndex() + results.hitWordsCount()

             + contextWordsAfterHit - baseIndex;

         while (words.hasMoreWords() && words.wordIndex() < limitIndex) {

           String word = words.nextWord();

           if (!word.startsWith("#")) {

             if (words.hadBreak() && buf.length() > 0)

               buf.append(' ');

             buf.append(word);

           }

         }

         // lastIndex = results.currentWordIndex() + results.hitWordsCount();

         results.skipToNextHit();

       } while (results.currentWordIndex() != -1

           && (results.currentWordIndex() - baseIndex) - words.wordIndex() < wordsGapBetweenAreas);

       bodyPosition += words.bytesReadFromUnderlyingStream();

       return buf.toString();

     } catch (IOException e) {

       System.err.println(e);

       try {

         body.close();

       } catch (Exception ee) {

       }

       return null;

     }

   }

   public static void main(String[] args) throws Exception {

     IndexOther fti = new IndexOther(new File("/tmp"));

     SearchResults rawResults;

     if (args[0].charAt(0) == '_') {

       args[0] = args[0].substring(1);

       rawResults = fti.groupSearchResults(args);

       System.out.println("phrase");

     } else if (args[0].equals("-query")) {

       rawResults = fti.querySearchResults(args[1]);

     } else {

       rawResults = fti.andSearchResults(args);

       System.out.println("and");

     }

     ContextSearchResults results = new ContextSearchResults(new Library() {

       public Text text(final long textID) {

         return new Text() {

           public InputStream body() throws IOException {

             return new FileInputStream(

                 "/usr/doc/HOWTO/other-formats/html/CDROM-HOWTO-3.html");

           }

           public InputStream bodyForFragment() throws IOException {

             return body();

           }

           public long ftiTextID() {

             return textID;

           }

         };

       }

     }, rawResults, fti);

     for (results.gotoText(0); results.currentTextID() != -1;

     // FIXME this isn't very clever! (maybe?)

     results.gotoText(results.currentTextID() + 1)) {

       System.out.println("== " + results.currentTextID());

       for (;;) {

         String anchor = results.currentAnchor();

         String area = results.nextArea();

         if (area == null)

           break;

         System.out.println("-- A HREF=http://doc#" + anchor);

         System.out.println(area);

       }

     }

   }

   public void close() {

     results.close();

     blockmarks.close();

     closeBody();

   }

 }