package dk.thoerup.traininfo.provider;

import java.io.StringReader;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;

import android.util.Log;
import dk.thoerup.traininfo.DepartureBean;
import dk.thoerup.traininfo.DepartureEntry;
import dk.thoerup.traininfo.util.AndroidTimeoutCache;
import dk.thoerup.traininfo.util.DownloadUtil;
import dk.thoerup.traininfo.util.XmlUtil;

public class XmlDepartureProvider implements DepartureProvider {

	final static int CACHE_TIMEOUT = 60*1000;
		
	
	AndroidTimeoutCache<String,DepartureBean> departureCache = new AndroidTimeoutCache<String,DepartureBean>(CACHE_TIMEOUT); 
	
		
	
	DepartureEntry tempDeparture;
	StringBuilder builder = new StringBuilder(512);
	

	
	@Override
	public DepartureBean lookupDepartures(int stationID, boolean arrival) {		
		
		String key = "" + stationID + ":" + arrival;
		
		DepartureBean departures = departureCache.get(key);
	
		if (departures == null) {			
			departures = lookupDeparturesWorker(stationID, arrival);
			
			if (departures != null) {			
				departureCache.put(key, departures);
			}
			
		} else {
			Log.i("XmlDepartureProvider", "cache hit !!!");
		}		
		
		return departures;
	}
	
	private DepartureBean lookupDeparturesWorker(int stationID, boolean arrival) {

		try
		{	
			int iArrival = arrival ? 1 : 0;
			String url = XmlUtil.SERVICE_BASE + "/DepartureServlet?format=xml&station=" + stationID + "&arrival=" + iArrival;
			Log.i("xmlurl",url);
			String doc =  DownloadUtil.getContentString(url, 30000, "ISO-8859-1");
			
			InputSource source = new InputSource( new StringReader(doc));
			
			SAXParserFactory spf = SAXParserFactory.newInstance();
            SAXParser sp = spf.newSAXParser();
            XMLReader xr = sp.getXMLReader();

            DepartureParser departureParser = new DepartureParser();
			xr.setContentHandler(departureParser);
			xr.setErrorHandler(departureParser);
			xr.parse(source);
			
			return departureParser.getDepartures();
			
		} catch (Exception e) {
			Log.e("XmlDepartureProvider", "looupFunction", e);
			return null;
		}		
	}
	

	class DepartureParser extends DefaultHandler { 
		
		private DepartureBean departures = new DepartureBean(); 

		public DepartureBean getDepartures() {
			return departures;
		}
	
		// this can be called several times fore the same text-node if there are many chardata / lines
		@Override
		public void characters (char ch[], int start, int length) 
		{		
			builder.append(ch, start, length);
		}
		
		@Override
		public void startElement (String uri, String name, String qName, Attributes atts)throws SAXException
		{
			if (name.equalsIgnoreCase("train"))
				tempDeparture = new DepartureEntry();
			
			builder.setLength(0); //reset StringBuilder
		}
		
		@Override
		public void endElement (String uri, String name, String qName) throws SAXException
		{
			if (name.equals("train")) {			
				departures.entries.add( tempDeparture );
			} else if (name.equals("time")) {
				tempDeparture.setTime(builder.toString().trim());
			} else if (name.equals("updated")) {
				tempDeparture.setLastUpdate(builder.toString().trim());
			} else if (name.equals("trainnumber")) {
				tempDeparture.setTrainNumber(builder.toString().trim());
			} else if (name.equals("destination")) {
				tempDeparture.setDestination(builder.toString().trim());
			} else if (name.equals("origin")) {
				tempDeparture.setOrigin(builder.toString().trim());
			} else if (name.equals("location")) {
				tempDeparture.setLocation(builder.toString().trim());
			} else if (name.equals("status")) {
				tempDeparture.setStatus(builder.toString().trim());
			} else if (name.equals("note")) {
				tempDeparture.setNote(builder.toString().trim());
			} else if (name.equals("type")) {
				tempDeparture.setType(builder.toString().trim());
			} else if (name.equals("notification")) {
				departures.notifications.add( builder.toString().trim() );
			}
		}
	}
}