source: trunk/gsdl3/src/java/org/greenstone/gsdl3/gs3build/extractor/IndexExtractor.java@ 5947

package org.greenstone.gsdl3.gs3build.extractor;

import java.io.FileReader;

import java.util.List;
import java.util.ArrayList;

import org.xml.sax.XMLReader;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.Attributes;
import org.xml.sax.helpers.XMLReaderFactory;
import org.xml.sax.helpers.DefaultHandler;

import org.greenstone.gsdl3.gs3build.doctypes.DocumentID;
import org.greenstone.gsdl3.gs3build.doctypes.DocumentInterface;
import org.greenstone.gsdl3.gs3build.doctypes.IndexDocument;
import org.greenstone.gsdl3.gs3build.doctypes.DocumentLoader;

public class IndexExtractor implements ExtractorInterface
{
  class IndexHandlerException extends Exception
  { public IndexHandlerException(String value)
    { super(value);
    }
  }

  /**
   *  An inner class to handle GML files
   */
  class IndexHandler
  { String  content;
    String  line;
    int     pos;
    boolean doneRow;
    List    labels;

    IndexHandler(String content) throws IndexHandlerException
    { this.content = content;
      this.doneRow = false;
      this.labels  = new ArrayList();

      // get the first line
      this.getLine();

      if (!this.hasMore())
      { throw new IndexHandlerException("No title line");
      }
      
      // get the first totem - it should be blank
      
    }

    private boolean hasMore()
    { return this.line != null;
    }

    private boolean hasMoreLines()
    { return this.content != null;
    }

    private String getEntry()
    { int tab = this.line.indexOf('\t');
      String reply;
    
      if (tab < 0) {
    reply = this.line;
    this.line = null;
      }
      else {
    reply = this.line.substring(0, tab);
    this.line = this.line.substring(tab+1);
      }

      return reply;
    }

    private String getLine()
    { do {
        int eol = this.content.indexOf('\n');
    if (eol < 0) {
      this.line = this.content;
      this.content = null;
    }
    else {
      this.line = this.content.substring(0, eol);
      this.content = this.content.substring(eol+1);
      while (this.content.length() > 0 &&
         this.content.charAt(0) < ' ')
      { this.content = this.content.substring(1);
      }
    }

    if (this.line != null) {
      this.line.trim();
    }
      } while (this.line != null && this.line.length() == 0);
      return this.line;
    }
  }

  /**
   *  Construct of extractor
   */
  public IndexExtractor()
  { // Intentionally left blank
  }

  /**
   *  This extractor doesn't need to do any preparation/completion work,
   *  so this member function is empty.
   */
  public void configure(String outputDir)
  { // Intentionally left blank
  }

  /**
   *  This extractor doesn't need to do any preparation/completion work,
   *  so this member function is empty.
   */
  public void startPass(int passNo)
  { // Intentionally left blank
  }

  /**
   *  Process the document - for a GML document, this results in the
   *  decoration of other files, for other documents, it does nothing.
   */
  public void extractDocument(DocumentID docID, DocumentInterface document)
  { if (document.getDocumentType().equals(IndexDocument.INDEX_DOCUMENT_TYPE))
    { // Extract the content from the index file
      
      // get the file
    String documentText = null;
    //      String documentText = 
    //  DocumentLoader.getAsString(document.getDocumentFiles().getFile(0).toString());
    
      if (documentText == null) {
    System.err.println("IndexExtractor: Unable to load any content for " + document.getDocumentFiles().getFile(0).toString());
    return;
      }

      try {
      IndexHandler handler = new IndexHandler(documentText);
      }
      catch (IndexHandlerException ex) {
      }
      
      // for each document post it to the corresponding document
    }
  }

  protected static void postMetadata(String file, String value, String label)
  {
  }

  /**
   *  This extractor doesn't need to do any preparation/completion work,
   *  so this member function is empty.
   */
  public void endPass(int passNo)
  { // Intentionally left blank
  }

  /**
   *  This extractor is a simple, single-pass extractor
   *
   *  @see: org.greenstone.gsdl3.gs3build.extractor.ExtractorInterface:getNumberOfPasses
   */
  public int getNumberOfPasses()
  { return 1;
  }
}