package dk.thoerup.traininfoservice.banedk;

import java.io.IOException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.DOMImplementation;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

import dk.thoerup.traininfoservice.DBConnection;

/**
 * Servlet implementation class DepartureServlet
 */
public class DepartureServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	
	Logger logger = Logger.getLogger( DepartureServlet.class.getName() );

	DepartureFetcher fetcher = new DepartureFetcher();
    TransformerFactory transformerFactory = TransformerFactory.newInstance();
	DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
	

	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		int station = Integer.parseInt( req.getParameter("station") );
		String format = req.getParameter("format");

		List<DepartureBean> beans;

		String stationName = getStationName(station);

		try {
			beans = fetcher.cachedLookupDepartures(station);
		} catch (java.net.SocketTimeoutException ste) {
			logger.warning("Read timed out, station="+station);
			resp.sendError(500);
			return;
		} catch (Exception e) {
			logger.log(Level.WARNING, "Unknown exception, station=" +station, e);
			resp.sendError(500);
			return;
		}
		
		resp.setDateHeader("Expires", 0);
		resp.setHeader("Cache-Control", "no-cache, must-revalidate");
		
		if (format.equalsIgnoreCase("xml")) {
			resp.setContentType("text/xml");
			resp.getWriter().print( formatXml(beans, stationName) );
		} else if (format.equalsIgnoreCase("html")) {
			req.setAttribute("stationname", stationName );
			req.setAttribute("departurebeans", beans);
			req.setAttribute("stationID", station );
			getServletContext().getRequestDispatcher("/ViewDepartures.jsp").forward(req,resp);
		} else {
			throw new ServletException("Unknown format");
		}

	}

	protected String formatXml(List<DepartureBean> beans, String stationName) throws ServletException{
		String xml = "";
		try {
			DocumentBuilder builder = docBuilderFactory.newDocumentBuilder();
			DOMImplementation impl = builder.getDOMImplementation();

			
			Document doc = impl.createDocument(null,null,null);
	        Element root = doc.createElement("departureinfo");
	        root.setAttribute("station", stationName);
	        for (DepartureBean departure : beans) {
	        	Element train = doc.createElement("train");
	        	
	        	Element time = doc.createElement("time");
	        	time.setTextContent( departure.getTime() );
	        	train.appendChild(time);
	        	
	        	Element updated = doc.createElement("updated");
	        	updated.setTextContent( String.valueOf(departure.getUpdated()) );
	        	train.appendChild(updated);
	        	
	        	Element trainNumber = doc.createElement("trainnumber");
	        	trainNumber.setTextContent( departure.getTrainNumber() );
	        	train.appendChild(trainNumber);
	        	
	        	Element destination = doc.createElement("destination");
	        	destination.setTextContent( departure.getDestination());
	        	train.appendChild(destination);
	        	
	        	Element origin = doc.createElement("origin");
	        	origin.setTextContent( departure.getOrigin() );
	        	train.appendChild(origin);
	        	
	        	Element location= doc.createElement("location");
	        	location.setTextContent( departure.getLocation() );
	        	train.appendChild(location);
	        	
	        	Element status = doc.createElement("status");
	        	status.setTextContent( departure.getStatus() );
	        	train.appendChild(status);
	        	
	        	Element note = doc.createElement("note");
	        	note.setTextContent( departure.getNote() );
	        	train.appendChild(note);
	        	
	        	root.appendChild(train);
	        }
	        
	        doc.appendChild(root);
	        
	        
	        DOMSource domSource = new DOMSource(doc);

	        Transformer transformer = transformerFactory.newTransformer();
	        //transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
	        transformer.setOutputProperty(OutputKeys.METHOD, "xml");
	        transformer.setOutputProperty(OutputKeys.ENCODING,"ISO-8859-1");
	        transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
	        transformer.setOutputProperty(OutputKeys.INDENT, "yes");
	        java.io.StringWriter sw = new java.io.StringWriter();
	        StreamResult sr = new StreamResult(sw);
	        transformer.transform(domSource, sr);
	        xml = sw.toString();


		} catch (Exception e) {
			throw new ServletException(e);
		}
		return xml;
	}

	protected String getStationName(int stationID) {
		String station = "";

		Connection conn = null;
		try {
			conn = DBConnection.getConnection();
			Statement stmt = conn.createStatement();
			ResultSet rs = stmt.executeQuery("SELECT name FROM trainstations WHERE id=" + stationID);
			if (rs.next()) {
				station = rs.getString(1);
			}

		} catch (Exception e) {	
		} finally {
			try {
				if (conn != null && !conn.isClosed())
					conn.close();
			} catch (Exception e) {}
		}

		return station;
	}

}