/**
 * This converts a bibtex file into Dublin Core RDFXML.  This
 * example treats all of the authors as string literals.
 */

//Import every class and interface by name.
import java.io.PrintWriter;
import java.io.Writer;
import java.io.InputStreamReader;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.OutputStream;

import java.util.StringTokenizer;
import java.util.Vector;

//The Dublin Core
import com.hp.hpl.mesa.rdf.jena.vocabulary.DC;

//Use the memory model implementation
import com.hp.hpl.mesa.rdf.jena.mem.ModelMem;

//Model package imports
import com.hp.hpl.mesa.rdf.jena.model.Model;
import com.hp.hpl.mesa.rdf.jena.model.Resource;
import com.hp.hpl.mesa.rdf.jena.model.Property; 
import com.hp.hpl.mesa.rdf.jena.model.Statement; 
import com.hp.hpl.mesa.rdf.jena.model.StmtIterator;
import com.hp.hpl.mesa.rdf.jena.model.RDFNode;
import com.hp.hpl.mesa.rdf.jena.model.RDFException;

public class DublinCoreEx4 {
  //Some bibtex constants
  final String AUTHOR="AUTHOR";
  final String TITLE="TITLE";
  final String INSTITUTION="INSTITUTION";
  final String YEAR="YEAR";
  final String JOURNAL="JOURNAL";

  //Base URI for the papers.
  final String baseUri="http://cgl.indiana.edu/publications/";

  //Some classwide variables.
  Model model=null;

  public DublinCoreEx4() {
    model=new ModelMem();
  }

  //Reads 
  public String readBibtexFile(String filename) throws IOException {
    String accumulate="";
    BufferedReader buf=new BufferedReader(new FileReader(filename));
    String line=buf.readLine();
    while(line!=null) {
      accumulate+=line+"\n";
      line=buf.readLine();
    }
    return accumulate;
  }

  public void parseEntries(String acc) throws RDFException {
    StringTokenizer st=new StringTokenizer(acc,"@");
    int index=0;
    while(st.hasMoreTokens()) {
      //First, create a resource.
      String resourceUri=baseUri+"Publication"+index;
      index++;
      Resource publication=model.createResource(resourceUri);

      //Next, parse the input file and fill out the resource.
      String test=st.nextToken();
      String type=acc.substring(0,acc.indexOf("{"));
      String token="\n";
      StringTokenizer st2=new StringTokenizer(test,token);
      while(st2.hasMoreTokens()) {
        String toparse=st2.nextToken();
        if(toparse.indexOf(AUTHOR)>-1) {
          Vector authors=parseAuthors(toparse);
          for(int i=0;i<authors.size();i++) {
            publication.addProperty(DC.creator,(String)authors.get(i));
          }
        }
        if(toparse.indexOf(TITLE)>-1) {
          String title=parseTitle(toparse);
          publication.addProperty(DC.title,title);
        }
        if(toparse.indexOf(JOURNAL)>-1) {
          String journal=parseJournal(toparse);
        }
        if(toparse.indexOf(INSTITUTION)>-1) {
          String journal=parseInstitution(toparse);
        }
        if(toparse.indexOf(YEAR)>-1) {
          String year=parseYear(toparse);
          publication.addProperty(DC.date,year);
        }
      }
    }
  }

  private Vector csvToVector(String csvString) {
    StringTokenizer st=new StringTokenizer(csvString,",");
    Vector retvec=new Vector();
    while(st.hasMoreTokens()) {
      retvec.add(st.nextToken());
    }
    return retvec;
  }

  private Vector parseAuthors(String toparse) {
    Vector authors=null;
    String csvauthor=toparse.substring(toparse.indexOf("\"")+1,
                              toparse.lastIndexOf("\""));
    authors=csvToVector(csvauthor);
    for(int i=0;i<authors.size();i++) {
    }
    return authors;
  }

  private String parseTitle(String toparse) {
    String title="";
    title=toparse.substring(toparse.indexOf("\"")+1,
                            toparse.lastIndexOf("\""));
    return title;
  }
 
  private String parseJournal(String toparse){
    String journal="";
    journal=toparse.substring(toparse.indexOf("\"")+1,
                              toparse.lastIndexOf("\""));
    return journal;
  }

  private String parseYear(String toparse){
    String year="";
    year=toparse.substring(toparse.indexOf("\"")+1,
                           toparse.lastIndexOf("\""));
    return year;
  }

  private String parseInstitution(String toparse){
    String inst=toparse.substring(toparse.indexOf("\"")+1,
                                     toparse.lastIndexOf("\""));
    return inst;
  }


  /**
   * Prints the model out as RDF XML
   */
  public void printRDFXML(OutputStream out) throws RDFException {
    model.write(new PrintWriter(out),"RDF/XML-ABBREV");
  }
  
  
  public static void main(String[] args) throws Exception{
    DublinCoreEx4 dc4=new DublinCoreEx4();
    String junk=dc4.readBibtexFile("cgl-pubs.txt");
    dc4.parseEntries(junk);
    dc4.printRDFXML(System.out);
  }
}