package kr.ac.kaist.resl.lilliput.adaptor;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;

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.parsers.ParserConfigurationException;

import kr.ac.kaist.resl.lilliput.utility.TitanHelper;

import org.apache.commons.configuration.BaseConfiguration;
import org.apache.commons.configuration.Configuration;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

import com.thinkaurelius.titan.core.TitanFactory;
import com.thinkaurelius.titan.core.TitanGraph;
import com.tinkerpop.blueprints.Vertex;

/**
 * Servlet implementation class RFIDAdaptor
 */
public class RFIDAdaptor extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public RFIDAdaptor() {
        super();
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// Do Nothing
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		Configuration conf = new BaseConfiguration();
		conf.setProperty("storage.backend", "cassandra");
		conf.setProperty("storage.hostname", "127.0.0.1");
		TitanGraph g = TitanFactory.open(conf);
		
		try {
			
			InputStream is = request.getInputStream();
			
			DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
			DocumentBuilder dBuilder;
			dBuilder = dbFactory.newDocumentBuilder();
			Document doc = dBuilder.parse(is);
			doc.getDocumentElement().normalize();
			
			NodeList epcs = doc.getElementsByTagName("epc");
			List<Vertex> objects = new ArrayList<Vertex>();
			Vertex place = null ;
			for( int i = 0 ; i < epcs.getLength() ; i++ )
			{
				// EPC
				Node epc = epcs.item(i);
				String epcStr = epc.getTextContent();
				Vertex v = TitanHelper.getVertex(g, "epc", epcStr);
				if( v == null ){
					System.out.println("[RFIDAdaptor] Create New Vertex : " + epcStr );
					Vertex object = g.addVertex(null);
					object.setProperty("epc", epc.getTextContent());
					object.setProperty("ltype", "Object");
					objects.add(object);
				}
				else
				{
					System.out.println("[RFIDAdaptor] Existing Vertex : " + epcStr );
					objects.add(v);
				}
			}
			
			NodeList locs = doc.getElementsByTagName("logicalReader");
			if( locs.getLength() != 0 )
			{
				Node loc = locs.item(0);
				String locStr = loc.getTextContent();
				Vertex v = TitanHelper.getVertex(g, "epc", locStr);
				if( v == null ){
					System.out.println("[RFIDAdaptor] Create New Vertex : " + locStr );
					place = g.addVertex(null);
					place.setProperty("epc", loc.getTextContent());
					place.setProperty("ltype", "Place");
				}
				else
				{
					System.out.println("[RFIDAdaptor] Existing Vertex : " + locStr );
					place = v;
				}
			}
			
			for( int i = 0 ; i < objects.size() ; i++ )
			{
				g.addEdge(null, objects.get(i), place, "isLocatedIn");
				g.addEdge(null, place, objects.get(i), "isContaining");
			}
			
			g.commit();
			System.out.println("[RFIDAdaptor] Graph Committed ");
		
			response.setContentType("text/html;charset=UTF-8");
			PrintWriter out = response.getWriter();
			out.println("<html><head><meta http-equiv='Content-Type' content='text/html; charset=UTF-8'></meta></head><body>");
			out.println("[RFIDAdaptor] Graph Committed ");
			out.println("</body></html>");
			out.close();
			
			g.shutdown();
			
		} catch (ParserConfigurationException e) {
			g.shutdown();
		} catch (SAXException e) {
			e.printStackTrace();
			g.shutdown();
		}
		
		
	}

}