package dk.thoerup.traininfoservice.banedk;

import java.io.IOException;
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 dk.thoerup.circuitbreaker.CircuitBreakerException;
import dk.thoerup.traininfoservice.Statistics;

/**
 * Servlet implementation class 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();
		
		boolean useTempSite =  Boolean.parseBoolean( getServletContext().getInitParameter("usetempsite") );
		int cacheTimeout =  Integer.parseInt( getServletContext().getInitParameter("cache_timeout") );
		logger.info( "TimetableServlet, use temp site=" + useTempSite + ", cache=" + cacheTimeout);
		fetcher = new TimetableFetcher(useTempSite,cacheTimeout);
	}
	
	@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
		{
			List<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");
			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(List<TimetableBean> timetable) {
		StringBuffer sb = new StringBuffer();
		
		sb.append("<timetable>");
		
		for (TimetableBean bean : timetable) {
			sb.append("<entry");
			if (bean.isCurrent())
				sb.append(" current=\"true\"");
			sb.append(">");
			
			sb.append("<station>").append( bean.getStation() ).append("</station>");
			sb.append("<arrival>").append( bean.getArrival() ).append("</arrival>");
			sb.append("<departure>").append( bean.getDeparture() ).append("</departure>");
			sb.append("<stationid>").append( bean.getStationId() ).append("</stationid>");
			
			sb.append("</entry>");
		}
		
		sb.append("</timetable>");
		
		return sb.toString();
	}

}