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

public class LoginServlet extends HttpServlet
{
    
    /*
      The Salesman EJB is an entity ejb
    */
    SalesmanHome home;
    Salesman salesman;

    public void init() throws ServletException
    {
        try
        {
            System.out.println("trying to get initial context");
            Context ic = getInitialContext();
            System.out.println("Got InitContext");
            Object objRef = ic.lookup("Salesman");
            System.out.println("Got obj ref");
            home = (SalesmanHome) PortableRemoteObject.narrow(objRef,SalesmanHome.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 
   {
	 String name = null;
       String password = null;
       try
       {
           System.out.println("Within goGet");
           

            /*
             The parameter names are 'username' and 'password'
           */	
           name = req.getParameter("username");
           password = req.getParameter("password");
           if((name == null) || (name.length() <= 0) || (password == 0) || (password.length() <=0 ))
	     {
               res.sendRedirect(res.encodeURL("/Status.jsp?code=2"));
	     }

           name = name.trim();
           password =  password.trim();
           /*
             Try to see if a salesman by this 'name' exists. The finder method 
             findByName of the Salesman EJB, does this.  It returns a java.util.Collection 
             object containing the results of the search.
           */
	     Collection users = home.findByName(name);
                        
           
           if(users.size() <= 0)
           {
              /*
                No salesmen found by the specified name
              */
              res.sendRedirect(res.encodeURL("/Status.jsp?code=3"));
           }
    
           Iterator i = users.iterator();
           /*
             Iterate throught the search results of findByName. Check if the password of 
             any results matches  the password entered
           */
           while (i.hasNext()) 
           {
               Salesman salesman = (Salesman)i.next();
               String tmpPassword = (String)salesman.getPassword();
               if(password.equals(tmpPassword))
               {
	 	/*
                     Check if an old session exists. If it does then invalidate it and create
                     a new one
                   */
                   HttpSession sess = req.getSession(false);
                   if(sess != null) // a null is returned if an old session does not exist
			 {
                  	sess.invalidate(); //invalidate old session
                        
                   }
                   sess = req.getSession(); //create a new session
                   String id = (String)salesman.getPrimaryKey(); //get salesman's id
                   /*
                      At this point the salesman has been validated and his id obtained. Store these
                      parameters in the session. 
                   */
                   sess.setAttribute("SalesmanId",id);
                   sess.setAttribute("SalesmanName",name);
                   
                   res.sendRedirect(res.encodeURL("/MainMenu.jsp"));
                    
               }
            
          }
       }catch(Exception npe)
        {
		if((name == null) || (name.length() <= 0) || (password == 0) || (password.length() <=0 ))
		{
                res.sendRedirect(res.encodeURL("/Status.jsp?code=2"));
		}
		else
		    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;

    }

 }