//package xmlDOMParse;

import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.io.Serializable;
import java.lang.*;
import java.util.*;

import org.w3c.dom.*;
import org.apache.xerces.parsers.DOMParser;

import ui.DOMParserSaveEncoding;

import org.apache.regexp.*;

public class DOMParse {

  private Document xmlDocument;
  private static ArrayList authors = new ArrayList();
  private static ArrayList fullTextSrc = new ArrayList();
  private static String dateModified = new String();
  private static String dateCreated = new String();
  private static String titleDE = new String();
  private static String titleEN = new String();
  private static String cnote = new String();

  public DOMParse (Document pXMLDocument) {
    xmlDocument    = pXMLDocument;
    authors        = new ArrayList();
    fullTextSrc    = new ArrayList();
    dateModified   = new String();
    dateCreated    = new String();
    titleDE        = new String();
    titleEN        = new String();
    cnote          = new String();
  }

  private void parseDoc() throws RESyntaxException {
    NodeList nodes = xmlDocument.getChildNodes();
    extract(nodes);
  }

  private static void extract(NodeList nodes) throws RESyntaxException {
    int len = (nodes != null) ? nodes.getLength() : 0;
    for (int i=0; i < len; i++) {
      Node node = nodes.item(i);
      switch (node.getNodeType()) {

        case Node.DOCUMENT_NODE: {              // doesn't work at the moment
           String docNode = node.getNodeName(); // #FIXME#
           break;
        }

        case Node.ELEMENT_NODE: {

          if (node.getNodeName().equals("rdf:Description")) {
            /* Extracting the copyright note from the xml file if availabel */
            if (node.getParentNode().getNodeName().equals("dc:rights")) {
              Element element = (Element)node;
              RE regexp = new RE(" +");         // some text needs regexp to
              try {                             // be shown correctly
                String cnote = regexp.subst(element.getAttribute("rdfs:label"), " ");
                System.out.println(cnote);      // for testing
                if (cnote.length() == 0)        // I think this is stupid
                  throw new RESyntaxException("The copyright note is empty!");
              }
              catch (RESyntaxException reex) {
                System.err.println(reex);
              }
            }
            /* Extracting the authors from the xml file, there has to be at
             * least one author!
             */
            if (node.getParentNode().getNodeName().equals("rdf:li") && node.getParentNode().getParentNode().getNodeName().equals("rdf:Bag")) {
              Element element = (Element)node;
              System.out.println(element.getAttribute("vCard:FN")); // for testing
              authors.add(element.getAttribute("vCard:FN"));
            }
            /* Extracting the creation date of the xml file */
            if (node.getParentNode().getNodeName().equals("dcq:created")) {
              Element element = (Element)node;
              System.out.println(element.getAttribute("rdf:value")); // for testing
              dateCreated = element.getAttribute("rdf:value");
            }
            /* Extracting the modification date of the xml file. */
            if (node.getParentNode().getNodeName().equals("dcq:modified")) {
              Element element = (Element)node;
              System.out.println(element.getAttribute("rdf:value")); // for testing
              dateModified = element.getAttribute("rdf:value");
            }
          }

          if (node.getNodeName().equals("rdf:li")) {
            Element element = (Element)node;
            /* Extracting the resource of the publication. Should be at least
             * one item, at most three.
             */
            if (node.getParentNode().getNodeName().equals("rdf:Alt") && node.getParentNode().getParentNode().getNodeName().equals("dc:identifier")) {
              System.out.println(element.getAttribute("rdf:resource")); // for testing
              fullTextSrc.add(element.getAttribute("rdf:resource"));
            }
            /* Extracting title of the publication. */
            if (element.hasAttribute("xml:lang")) {
              NodeList nl = node.getChildNodes();
              for (int k=0; k < nl.getLength(); k++) {
                if ((nl.item(k)).getNodeType() == Node.TEXT_NODE) {
                  /* Looking for the German title */
                  if (element.getAttribute("xml:lang").equals("de")) {
                    RE regexp = new RE("\n");
                    try {
                      titleDE = regexp.subst((nl.item(k)).getNodeValue(), " ");
                      System.out.println("Deutscher Titel: " + titleDE);
                      if (titleDE.length() == 0) {
                        throw new RESyntaxException("No German title.");
                      }
                    }
                    catch (RESyntaxException reex) {
                      System.err.println(reex);
                    }
                  }
                  /* Looking for the English titel */
                  else {
                    RE regexp = new RE("\n");
                    try {
                      titleEN = regexp.subst((nl.item(k)).getNodeValue(), " ");
                      System.out.println("Englischer Titel: " + titleEN); // for testing
                      if (titleEN.length() == 0) {
                        throw new RESyntaxException("No English title.");
                      }
                    }
                    catch (RESyntaxException reex) {
                      System.err.println(reex);
                    }
                  }
                }
              }
            }
          }
        }
      /* Recursively calling the method. Could be done better. */
      extract(node.getChildNodes());
      break;

      }
    }
  }

  /* getMethods() could be useful later, i.e. for returning the nodes in the
   * applet.
   */
  public ArrayList getAuthors() {
    return authors;
  }

  public ArrayList getFullTextSrc() {
    return fullTextSrc;
  }

  public String getCNote() {
    return cnote;
  }

  public String getDateModified() {
    return dateModified;
  }

  public String getDateCreated() {
    return dateCreated;
  }

  public String getTitleDE() {
    return titleDE;
  }

  public String getTitleEN() {
    return titleEN;
  }

  /* Now fill in all extracted nodes in the Applet */
  private void fillInElements() {

    TextField cNoteF = new TextField();
    cNoteF.setText(getCNote());

    TextField dateCF = new TextField();
    dateCF.setText(getDateCreated());

    TextField dateMF = new TextField();
    dateMF.setText(getDateModified());

    TextField titleDEF = new TextField();
    titleDEF.setText(getTitleDE());

    TextField titleENF = new TextField();
    titleENF.setText(getTitleEN());

    TextField author1F = new TextField();
    String author1 = (String)getAuthors().get(0);
    author1F.setText(author1);

    /* is there a 2nd author? */
    if (getAuthors().get(1) != null) {
      TextField author2F = new TextField();
      String author2 = (String)getAuthors().get(1);
      author2F.setText(author2);
    }

    /* is there a 3rd author? */
    if (getAuthors().get(2) != null) {
      TextField author3F = new TextField();
      String author3 = (String)getAuthors().get(2);
      author3F.setText(author3);
    }

    /* is there a 4th author? */
    if (getAuthors().get(3) != null) {
      TextField author4F = new TextField();
      String author4 = (String)getAuthors().get(3);
      author4F.setText(author4);
    }

    /* just filling in the first resource for now */
    TextField fullTextSrcF = new TextField();
    String fullTextSrc = (String)getAuthors().get(0);
    fullTextSrcF.setText(fullTextSrc);
  }

  public static void main(String[] args) {
    String DEFAULT_PARSER_NAME = "org.apache.xerces.parsers.DOMParser";
    /* For now, there's the xercesSamples.jar necessary; it works but needs to
     * be done differently.
     */
    DOMParserSaveEncoding parser;
    Document xmlDocument;
    String filename=args[0];
    
    try {
      parser = new DOMParserSaveEncoding();
      /* setting some features, don't know if this is really necessary */
      parser.setFeature("http://apache.org/xml/features/dom/defer-node-expansion", false);
      parser.setFeature("http://apache.org/xml/features/continue-after-fatal-error", true);
      parser.setFeature("http://apache.org/xml/features/allow-java-encodings", true);

//      xmlDocument = parser.getDocument();
//      DOMParse doc = new DOMParse(xmlDocument);
//      doc.parseDoc();
      parser.parse(filename);
      Document document = parser.getDocument();
      NodeList nodes = document.getChildNodes();
      extract(nodes);
    }
    catch (Exception ex) {
      System.err.println(ex.getMessage());
      ex.printStackTrace();
    }
  }
}