import java.io.*;
import javax.servlet.http.*;
import javax.servlet.*;
import javax.rmi.*;
import javax.naming.*;
import java.util.*;


public class ClientViewServlet extends HttpServlet
{

    /*
      This servlet interacts with the Client Entity EJB. The client EJB has a finder 
     method, findBySalesman. This method accepts the salesman id and obtains 
     all the clients whom this salesman is supposed to visit.
    */ 
    ClientHome clientHome;
    
    public void init() throws ServletException
    {
        try
        {
            System.out.println("trying to get initial context");
            Context ic = (InitialContext) getInitialContext();
            System.out.println("Got InitContext");
            Object objRef = ic.lookup("Client");
            System.out.println("Got obj ref");
            clientHome = (ClientHome) PortableRemoteObject.narrow(objRef,ClientHome.class);
            System.out.println("Got Home");
        }catch(Exception e)
        {
            System.out.println("Error in init");
            e.printStackTrace();
        }
    }
    
    public void doGet(HttpServletRequest req,HttpServletResponse res) throws ServletException,IOException
    {
        
        try
        {
            HttpSession session = req.getSession(false);
            //obtain the salesman id from the session.
            String strSalesmanId = (String)session.getAttribute("SalesmanId");
            /*
              Use the salesman id to search for clients that the salesman is supposed to
              visit.
            */
            Collection clients = clientHome.findBySalesman(strSalesmanId);
            if(clients.size() <= 0) //No clients found
            {
                res.sendRedirect(res.encodeURL("/Status.jsp?code=4"));
            }
            /*
              Create an array of Vector objects. Each Vector object stores the 
              Client id - first position in Vector 
              Client Name - second position in Vector
              Client Address - third position in Vector
              It then stores this array of Vectors in the session
            */
              
            Vector cinfo[] = new Vector[clients.size()];
            Iterator i = clients.iterator();
            int cnt=0;
            

            while(i.hasNext())
            {
                
                Client client = (Client) i.next();
                cinfo[cnt] = new Vector(3);
                cinfo[cnt].add(client.getId());
                cinfo[cnt].add(client.getName());
                cinfo[cnt].add(client.getAddress());
                cnt++;
            
            }
            //Store the array of vectors in the session. Each Vector represents one client.
            session.setAttribute("ClientList",cinfo);
            //send redirection to ClientListJSP.
            res.sendRedirect(res.encodeURL("/ClientList.jsp"));
        }catch(Exception e){
            System.out.println("Error while obtaining client list:" + e.getMessage());
            res.sendRedirect(res.encodeURL("/Status.jsp?code=1"));

        }
    }
    
    private Context getInitialContext() throws NamingException
    {
        Context initial = null;
        try {
             /*
               There are other methods of obtaining the initial context too. Check the J2EE docs and
               your application server docs for these.
             */		
             initial = new InitialContext();
             
         
        }catch(Exception ne) {
          System.out.println("Unable to get an initial context");
        }
        return initial;
     }

}