/**************************************************************************
/* A factory for creating Lucene Documents. This factory actually only
/* creates a number of standard fields (path, type, date).
/*
/* Copyright (c) 2003-2004 by Bernhard Bablok (mail@bablokb.de)
/*
/* This library is free software; you can redistribute it and/or modify
/* it under the terms of the GNU Lesser General Public License as published
/* by  the Free Software Foundation; either version 2 of the License or
/* (at your option) any later version.
/*
/* This library is distributed in the hope that it will be useful, but
/* WITHOUT ANY WARRANTY; without even the implied warranty of
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
/* GNU Lesser General Public License for more details.
/*
/* You should have received a copy of the GNU Lesser General Public License
/* along with this library; see the file COPYING.LESSER.  If not, write to
/* the Free Software Foundation Inc., 59 Temple Place - Suite 330,
/* Boston, MA  02111-1307 USA
/**************************************************************************/

package de.bablokb.luala.lib;

import java.io.*;

import org.apache.lucene.document.*;

/**
   A factory for creating Lucene Documents. This factory actually only
   creates a number of standard fields (path, type, date). The content
   has to be added by subclasses. This factory can be used for binary
   files, since it stores at least the meta-info.

   <p> The document has three fields:
    <ul>
    <li><code>StandardDocumentFactory.PATH</code>: 
      containing the pathname of the file, as a stored, tokenized field;
    <li><code>StandardDocument.DATE</code>:
      the last-modified date of the file, as a searchable, non-tokenized field;
    <li><code>StandardDocumentFactory.TYPE</code>:
      the classname of StandardDocumentFactory.
    </p>
  
    <p>Subclasses should call the {@link #addContent}-method.
    </p>

    @version $Revision: 1.19 $
    @author  $Author: bablokb $
*/

public class StandardDocumentFactory implements DocumentFactory {

  ////////////////////////////////////////////////////////////////////////////

  /**
     Field for length of summary.
  */

  private int iSummaryLength = 512;

  ////////////////////////////////////////////////////////////////////////////

  /**
     Return summary length.
  */

  public int getSummaryLength() {
    return iSummaryLength;
  }

  ////////////////////////////////////////////////////////////////////////////

  /**
     Add the content.

     @param doc    The document
     @param reader The reader to add to the document.
  */

  public void addContent(Document doc, Reader reader) {
    doc.add(Field.Text(CONTENT,reader));
  }

  ////////////////////////////////////////////////////////////////////////////

  /**
     Add a summary (beginning of text) to the document. Should be called
     before {@link #addContent}.

     @param doc    The Lucene-document
     @param reader A reader
  */

  public void addSummary(Document doc, Reader reader) throws IOException {
    try {
      reader.mark(iSummaryLength+1);
      reader.reset();  // to bail out if reset() is not supported!
      reader.mark(iSummaryLength+1);
      char[] summary = new char[iSummaryLength];
      int size = reader.read(summary,0,summary.length);
      doc.add(Field.UnIndexed(SUMMARY,new String(summary,0,size)));
      reader.reset();
    } catch (Exception e) {
    }
  }

  ////////////////////////////////////////////////////////////////////////////

  /**
     Set the type-field of this document.

     @param doc  The document
  */

  public void setType(Document doc) {
    doc.add(Field.UnIndexed(TYPE,"application/octet-stream"));
  }

  ////////////////////////////////////////////////////////////////////////////

  /**
    Create a Lucene-Document.

    @param name The name of the source-document

    @return A {@link org.apache.lucene.document.Document}

    @throws FactoryException
  */

  public Document createDocument(String name) throws FactoryException {
    try {
      Document doc = new Document();
      doc.add(Field.Text(PATH,name));
      doc.add(Field.Keyword(DATE_MOD,
        DateField.timeToString((new File(name)).lastModified())));
      setType(doc);
      return doc;
    } catch (Exception e) {
      throw new FactoryException(e);
    }
  }
}