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


public class ItemListServlet extends HttpServlet
{

    
    ItemHome itemHome;
    
    public void init() throws ServletException
    {
        /*
          This Servlet functions in a similar manner to the ClientViewServlet. Only in this case it
          obtains the item list from the Item Entity EJB. Each item is represented by the Item Entity EJB.
        */
        try
        {
            System.out.println("trying to get initial context");
            Context ic = (InitialContext) getInitialContext();
            System.out.println("Got InitContext");
            Object objRef = ic.lookup("Item");
            System.out.println("Got obj ref");
            itemHome = (ItemHome) PortableRemoteObject.narrow(objRef,ItemHome.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);
            String clientCode = (String)req.getParameter("client");
            /*
              Store the client code in the session. This code is sent by the ClientDetailsJSP along with the request. 
           */
            session.setAttribute("ClientId",clientCode); 
            Collection items = itemHome.findAll(); //find all items.
            if(items.size() <= 0) //No items for sale
            {
                System.out.println("items size: " + items.size());
                res.sendRedirect(res.encodeURL("/Status.jsp?code=3"));
            }
            Vector itemInfo[] = new Vector[items.size()];
            Iterator i = items.iterator();
            int cnt=0;
            /*
                Structure of each Vector object
                Item Id - first position in Vector
                Item Name - second position in Vector
                Item Description - third position in Vector
           */

            while(i.hasNext())
            {
                
                Item item = (Item) i.next();
                itemInfo[cnt] = new Vector(3);
                itemInfo[cnt].add(item.getId());
                itemInfo[cnt].add(item.getName());
                itemInfo[cnt].add(item.getDescription());
                cnt++;
            
            }
            session.setAttribute("ItemList",itemInfo); //place the item list in the session.

            res.sendRedirect(res.encodeURL("/ItemList.jsp"));
        }catch(Exception e){
            System.out.println("Error while obtaining item 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;

   }

}