package dk.thoerup.traininfoservice.banedk;

import java.io.IOException;
import java.io.StringWriter;

import java.util.logging.Level;
import java.util.logging.Logger;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.simpleframework.xml.Serializer;
import org.simpleframework.xml.core.Persister;

import dk.thoerup.android.traininfo.common.TimetableBean;
import dk.thoerup.circuitbreaker.CircuitBreakerException;
import dk.thoerup.traininfoservice.Statistics;
import dk.thoerup.traininfoservice.TraininfoSettings;;

/**
 * Servlet implementation class TimetableServlet
 */
@WebServlet(urlPatterns={"/TimetableServlet"})
public class TimetableServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
	
	Logger logger = Logger.getLogger( TimetableServlet.class.getName() );
	
	TimetableFetcher fetcher;
	
	
	@Override
	public void init() throws ServletException {
		super.init();
		

		TraininfoSettings settings = (TraininfoSettings) getServletContext().getAttribute("settings");
		fetcher = new TimetableFetcher(settings);
	}
	
	@Override
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		if (request.getParameter("train") == null) {
			response.sendError(400, "not enough parameters (train)");
			return;
		}
		if (request.getParameter("type") == null) {
			response.sendError(400, "not enough parameters (type)");
			return;
		}
		Statistics.getInstance().incrementTimetableLookups();
		
		String train = request.getParameter("train").trim();
		String type = request.getParameter("type").trim();
				
		try
		{
			TimetableBean timetable = fetcher.cachedLookupTimetable(train, type);
		
			String responseXML = formatTimetable(timetable);
		
			response.setContentType("text/xml");
			response.getWriter().print(responseXML);
		} catch (java.io.IOException ioe) {
			logger.warning("(timetable) Read failed, type=" + type + ", train="+train + ". " + ioe.getMessage());
			Statistics.getInstance().incrementTimetableErrors();
			response.sendError(500, "Backend timed out");
		} catch (CircuitBreakerException cbe) {
			logger.warning("Circuitbreaker - failing fast, type=" + type + ", train="+train);
			Statistics.getInstance().incrementTimetableErrors();
			response.sendError(500);
		}catch (Exception e) {
			logger.log(Level.WARNING, "failure looking up timetable: type=" + type + ",train=" +train, e);
			Statistics.getInstance().incrementTimetableErrors();
			response.sendError(500);
		}
		
	}
	
	String formatTimetable(TimetableBean timetable) throws ServletException {
		Serializer serializer = new Persister();

		StringWriter out = new StringWriter();

		try {
			serializer.write(timetable, out);
		} catch (Exception e) {
			throw new ServletException(e);
		}
		
		return out.toString();
	}

}