/**
 * Defines a class to update table rates in the background
 */
package de.pointedears.converter.helpers;

import java.io.IOException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

/**
 * @author pelinux
 * 
 */
public class CurrenciesUpdateThread extends Thread
{
  private static final String URL_ECB =
    "http://www.ecb.europa.eu/stats/eurofxref/eurofxref-daily.xml"; //$NON-NLS-1$

  /**
   * Default constructor which sets the runnable
   * 
   * @param runnable
   */
  private CurrenciesUpdateThread(Runnable runnable)
  {
    super(runnable);
  }

  /**
   * Default constructor
   */
  public CurrenciesUpdateThread()
  {
    this(new Runnable() {
      @Override
      public void run()
      {
        DocumentBuilderFactory documentBuilderFactory =
          DocumentBuilderFactory.newInstance();
        documentBuilderFactory.setNamespaceAware(true);
        try
        {
          DocumentBuilder builder =
            documentBuilderFactory.newDocumentBuilder();
          try
          {
            Document doc = builder.parse(CurrenciesUpdateThread.URL_ECB);
            XPathFactory xpathFactory = XPathFactory.newInstance();
            XPath xpath = xpathFactory.newXPath();
            try
            {
              XPathExpression expr = xpath.compile("/Cube/Cube//Cube"); //$NON-NLS-1$
              Object result = expr.evaluate(doc, XPathConstants.NODESET);
              NodeList nodes = (NodeList) result;
              for (int i = 0, len = nodes.getLength(); i < len; i++)
              {
                Node item = nodes.item(i);
                NamedNodeMap attributes = item.getAttributes();
                String currency =
                  attributes.getNamedItem("currency").getNodeValue(); //$NON-NLS-1$
                String rate = attributes.getNamedItem("rate").toString(); //$NON-NLS-1$

                /* TODO: Update UI */
                System.out.println(currency + ": " + rate); //$NON-NLS-1$
              }
            }
            catch (XPathExpressionException e)
            {
              // TODO Auto-generated catch block
              e.printStackTrace();
            }
          }
          catch (SAXException e)
          {
            // TODO Auto-generated catch block
            e.printStackTrace();
          }
          catch (IOException e)
          {
            // TODO Auto-generated catch block
            e.printStackTrace();
          }
        }
        catch (ParserConfigurationException e)
        {
          // TODO Auto-generated catch block
          e.printStackTrace();
        }
      }
    });
  }
}