/**
 *  CIS 525 Project #3
 *  David Henderson
 *  Java Program
 *  This applet called "VamlorClient.java" uses RMI (Remote Method Invocation)
 *  to communicate with a server. The applet reads data from the server then
 * presents it to the user (see documentation)
 *
 * @version 1.0
 * @author Copyright 2000 - David Henderson
 */
import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
import java.rmi.Naming;
import java.rmi.RemoteException;
import java.net.MalformedURLException;
import java.rmi.NotBoundException;
import java.util.*;

public class VamlorClient extends Applet {
  VamlorRMI vamlor;				// A vamlor is an E-animal. It virtually walks,
								// runs, sleeps, and eats.
  Label locationLabel;			// The label displaying the vamlor's location
								// (0-249, 0-249)
  Label energyLabel;			// The label displaying the vamlor's energy
								// 0-3000
  Label healthLabel;			// The label displaying the vamlor's health
								// 0-3000
  Label stateLabel;				// The label displaying the vamlor's state
								// Walking, Running, Sleeping
  Choice menu;					// Vamlor selection menu
  Timer timer = new Timer();	// This timer updates the Vamlor values
  Timer menutimer = new Timer();// This timer updates the Vamlor menu
  
  
  /** Redraw - Inner class used as a timer. At a scheduled interval, this will
  fire then update all Vamlor values */ 
  private class Redraw extends TimerTask {

      public VamlorClient vam;

	  // Hang on to this applet so we can access the members
      public Redraw(VamlorClient v) {
          vam = v;
      }

	  // This gets called every time the timer expires
      public void run() {
          vam.redrawit();
      }
  }

  /** MenuDraw - Inner class used as a timer. At a scheduled interval, this will
  fire then update Vamlor menu */
  private class MenuDraw extends TimerTask {

      public VamlorClient vam;

	  // Hang on to this applet so we can access the members
      public MenuDraw(VamlorClient v) {
          vam = v;
      }

	  // This gets called every time the timer expires
      public void run() {
          vam.menudraw();
      }
  }
  
  /** createMenuItems - Applet method that gets called to re-create the menu
  with all of the alive Vamlors. The server will send an integer list 
  indicating the IDs of the existing Vamlors */
  private void createMenuItems() {
	 int [] vlist;	// List of existing vamlors
	 String vname;	// Vamlor name
	 
	 menu.removeAll();	// Clean out all menu items first
	 
	 // Whenever we use RMI, we must catch the exceptions
	 try {
		 vlist = vamlor.getIDList(); // Get the list of Vamlor IDs from server

		 // As long as we have at least one, build up the menu of Vamlors.
		 // The format is "ID - Name"
		 if (vlist != null && vlist.length > 0) {
			for (int i = 0; i < vlist.length; i++) {
				 vname = vamlor.getName(vlist[i]);
				 if (vname != null)
					 menu.addItem(vlist[i] + " - " + vname);
			}
		 } else {
			 menu.addItem("No Vamlors Alive");	// Display this when no Vamlors
		 }
		 
     } catch (Exception e) {
		 // Indicate that we could not connect to server
		 menu.addItem("Nothing to Select");
		 add("South", new Label("Error-Cannot Connect To Server", Label.CENTER));
         System.out.println(e);
     }
  }
  
  /** menudraw - Applet method that gets called at specified intervals to
  update the menu */
  private void menudraw() {	 
	  // Preserve the current selection 
	 String currentSelection = menu.getSelectedItem();
	 createMenuItems();
	 menu.select(currentSelection);
  }
  
  /** redrawit - Applet method that gets called at specified intervals to
  update the Vamlor values */
  private void redrawit() {
	String locstr = "";
	String energystr = "";
	String healthstr = "";
	String statestr = "";
	int v_id;

	// Get the currently selected Vamlor
	String currentSelection = menu.getSelectedItem();
	
	// Determine the ID of the Vamlor by parsing the String
	StringTokenizer st = new StringTokenizer(currentSelection);
	try {
		v_id = Integer.parseInt(st.nextToken());
	} catch (Exception e) {
		v_id = 0;
	}
	
	// If we did not get back any Vamlors, indicate that there is a problem
	if (v_id == 0) {
		locstr = "Not Initialized";
		energystr = "Not Initialized";
		healthstr = "Not Initialized";
		statestr = "Not Initialized";
	} else { 
		try {
			
			// Four server methods are called to get the status of the selected
			// Vamlor.
			//getX, getY - Gives its location (0-249, 0-249)
			locstr = "Location: " + "(" + vamlor.getX(v_id) + ", " + vamlor.getY(v_id) + ")";
			// getEnergyLevel - Gives its energy level 0-3000
			energystr = "Energy Level: " + vamlor.getEnergyLevel(v_id);
			// getHealthLevel - Gives its health level 0-3000
			healthstr = "Health Level: " + vamlor.getHealthLevel(v_id);
			// getState - Gives its state (Running, Walking, or Sleeping)
			String returned = vamlor.getState(v_id);
			// Check for valid returned string
			if (returned != null)
				statestr = "Life State: " + returned;
		} catch (Exception e) {
			// Indicate that we could not connect to server
			add("South", new Label("Error-Cannot Connect To Server", Label.CENTER));
		    System.out.println(e);
		}
	}

	// Update the four status labels
	locationLabel.setText(locstr);
	energyLabel.setText(energystr);
	healthLabel.setText(healthstr);
	stateLabel.setText(statestr);
  }

  /** init - Applet method. This is called when the applet is first loaded.
  */
  public void init() {
	  // Try to connect to the server. We lookup the registered service using
	  // the "Naming" mechanism. 
	try {
	    vamlor = (VamlorRMI)Naming.lookup("//localhost/VamlorRMIService");
	}
	
	// Catch all of the different reasons why we could not connect.
	// NOTE: This is for debugging purposes since the user does not need
	// to know about the details.
	catch (MalformedURLException murle) {
	    System.out.println();
	    System.out.println("MalformedURLException");
	    System.out.println(murle);
		add("South", new Label("Error-Cannot Connect To Server", Label.CENTER));
	}
	catch (RemoteException re) {
	    System.out.println();
	    System.out.println("RemoteException");
	    System.out.println(re);
		add("South", new Label("Error-Cannot Connect To Server", Label.CENTER));
	}
	catch (NotBoundException nbe) {
	    System.out.println();
	    System.out.println("NotBoundException");
	    System.out.println(nbe);
		add("South", new Label("Error-Cannot Connect To Server", Label.CENTER));
	}
	catch (
	    java.lang.ArithmeticException ae) {
	    System.out.println();
	    System.out.println("java.lang.ArithmeticException");
	    System.out.println(ae);
		add("South", new Label("Error-Cannot Connect To Server", Label.CENTER));
	}
	// Gray background
    setBackground(Color.gray);
	
	// Set up a Border Layout for the Applet
    setLayout(new BorderLayout());
	
	// Add all of the Applet components
    addComponents();
	
	// Query the server for the selected Vamlor's values every 3 seconds
    timer.scheduleAtFixedRate(new Redraw(this), 3000, 3000);
	
	// Create Vamlor Menu Items for the first time
	createMenuItems();
	
	// Select the first item for now
	menu.select(0);
	
	// Query the server for the Vamlor list every 10 seconds
	timer.scheduleAtFixedRate(new MenuDraw(this), 10000, 10000);
  }

  /** addComponents - Applet method which adds all of the components to the Applet 
   */
  private void addComponents() {  

	  // First change the Font for the eintire applet
	setFont(new Font("Helvetica", Font.BOLD, 14));
	
	// This panel contains components for the menu
	Panel menuPanel = new Panel();
	// This panel contains components for the Vamlor values
	Panel workPanel = new Panel();
	
	// We select a 2 by 2 grid for holding the Vamlor status values
	GridLayout grid = new GridLayout(2,2);
	grid.setVgap(0);	// Vertical gap is zero for each row
	workPanel.setLayout(grid);
	
	// Create the Vamlor menu listing all available Vamlors from server
	menu = new Choice();
	// This just makes menu large enough to hold IDs + Names.
	// Setting the width does not work
	menu.addItem("DUMMYDUMMYDUMMYDUMMY");
    
	// Add the menu label to the panel
	menuPanel.add(new Label("Choose Vamlor:", Label.LEFT));
	// Then add the menu itself
	menuPanel.add(menu);
	
	// Add each Vamlor label to the Applet
	// Health, Energy, Location, State
	locationLabel = new Label("", Label.LEFT);
	workPanel.add(locationLabel);
	energyLabel = new Label("", Label.LEFT);
	workPanel.add(energyLabel );
	healthLabel = new Label("", Label.LEFT);
	workPanel.add(healthLabel);
	stateLabel = new Label("", Label.LEFT);
	workPanel.add(stateLabel);
	
	add("North", menuPanel);
	add("Center", workPanel);
	
	//Update the values for the first time
	redrawit();
  }
}