/**************************************************************************
/* Render a document which follows the StandardDocument standard.
/*
/* 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.*;

/**
   Render a document which follows the StandardDocument standard.

   @see StandardDocumentFactory

   @version $Revision: 1.8 $
   @author  $Author: bablokb $
*/

public abstract class StandardDocumentRenderer implements DocumentRenderer {


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

  /**
     Render summary: if true, also render summary-field (if available)
  */

  private boolean iShowSummary = true;

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

  /**
     Header-String (first-part of output-string).
  */

  private String iHeader;

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

  /**
     Footer-String (last-part of output-string).
  */

  private String iFooter;

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

  /**
     Prefix-String (added to every path).
  */

  private String iPrefix;

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

  /**
     Set the header.

     @param header The header to use.
  */

  public void setHeader(String header) {
    iHeader = header;
  }

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

  /**
     Set the footer.

     @param footer The footer to use.
  */

  public void setFooter(String footer) {
    iFooter = footer;
  }

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

  /**
     Set the prefix.

     @param prefix The prefix to use.
  */

  public void setPrefix(String prefix) {
    iPrefix = prefix;
  }

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

  /**
     Set the showSummary-attribute.

     @param flag if true, show the summary.
  */

  public void setShowSummary(boolean flag) {
    iShowSummary = flag;
  }

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

  /**
     This method will render the PATH-field of the document. If the PATH-field
     is not set, an IllegalStateException is thrown.

     @throws IOException
     @throws IllegalStateException if document contains no PATH-field
  */

  public String renderPath(Document doc)
                                   throws IOException, IllegalStateException {
    String path = doc.get(DocumentFactory.PATH);
    if (path != null) {
      if (iPrefix != null)
	path = iPrefix + path;
    } else
      throw new IllegalStateException("error: missing " + 
        DocumentFactory.PATH + "-field in document!");
    return path;
  }

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

  /**
     This method will render the Summary-field of the document. This is a
     noop and must be implemented by subclasses.

     @throws IOException
     @throws IllegalStateException if document contains no PATH-field
  */

  public abstract String renderSummary(Document doc)
    throws IOException, IllegalStateException;

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

  /**
     {@inheritDoc}

     This method will render the hit.

     @throws IllegalStateException
  */

  public String render(Document doc) throws IOException, IllegalStateException {
    StringBuffer buffer = new StringBuffer();
    if (iHeader != null)
      buffer.append(iHeader);
    String path = renderPath(doc);
    if (path != null)
      buffer.append(path);
    String summary = renderSummary(doc);
    if (summary != null)
      buffer.append(summary);
    if (iFooter != null)
      buffer.append(iFooter);
    return buffer.toString();
  }
}