package edu.gac.max.gened;

import java.awt.TextField;
import java.awt.Checkbox;
import java.awt.List;
import java.awt.Label;
import java.awt.Panel;
import java.awt.Button;
import java.awt.FlowLayout;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.util.Vector;

public class Finder extends java.applet.Applet
  implements ActionListener {

  // Note that the HTML file containing this applet needs to provide
  // a parameter, called server, used to construct the URL for contacting
  // the RMI server.  For example, if the server parameter is max-gened,
  // and this applet is served off of the kilpinen.mcs.gac.edu (i.e.,
  // that is the "codebase"), then the RMI URL will be
  //  rmi://kilpinen.mcs.max.edu/max-gened

  private boolean isAlive = true;
  private Server server;
  private List coursesDisplay;
  private Checkbox[] areaCheckboxes;
  private char[] dayNames = {'M', 'T', 'W', 'R', 'F'};
  private char[] periodNames = {'1', '2', '3', '4', '5', '6', '7', '8', '9',
                                'A', 'B', 'C', 'D', 'E',
                                'W', 'X', 'Y', 'Z'};
  private Checkbox[][] conflictCheckboxes;

  public void init(){
    setLayout(new BorderLayout());
    coursesDisplay = new List();
    add(coursesDisplay, "Center");
    Panel inputPanel = new Panel();
    inputPanel.setLayout(new BorderLayout());
    Panel areaPanel = new Panel();
    areaPanel.setLayout(new FlowLayout());
    String[] areaNames = {"A", "P", "B", "C", "D", "LD", "E", "F", "G", "GN"};
    areaCheckboxes = new Checkbox[areaNames.length];
    for(int i = 0; i < areaNames.length; i++){
      areaCheckboxes[i] = new Checkbox(areaNames[i]);
      areaPanel.add(areaCheckboxes[i]);
    }
    inputPanel.add(areaPanel, "North");
    Panel conflictPanel = new Panel();
    conflictPanel.setLayout(new GridLayout(periodNames.length + 1,
                                           dayNames.length + 1));
    conflictPanel.add(new Label()); // empty where row, col. labels intersect
    for(int i = 0; i < dayNames.length; i++){
      conflictPanel.add(new Label(""+dayNames[i]));
    }
    conflictCheckboxes = new Checkbox[periodNames.length][dayNames.length];
    for(int i = 0; i < periodNames.length; i++){
      conflictPanel.add(new Label(""+periodNames[i]));
      for(int j = 0; j < dayNames.length; j++){
        Checkbox c = new Checkbox();
        conflictCheckboxes[i][j] = c;
        conflictPanel.add(c);
      }
    }
    Panel conflictPanelPanel = new Panel(); // prevents stretching grid to
    conflictPanelPanel.setLayout(new FlowLayout()); // full width of applet
    conflictPanelPanel.add(conflictPanel);
    inputPanel.add(conflictPanelPanel, "Center");
    Panel buttonPanel = new Panel();
    buttonPanel.setLayout(new FlowLayout());
    Button b = new Button("Find");
    b.addActionListener(this);
    buttonPanel.add(b);
    inputPanel.add(buttonPanel, "South");
    add(inputPanel, "North");
    try{
      server = (Server) java.rmi.Naming.lookup
        ("rmi://" + getCodeBase().getHost() + "/"
         + getParameter("server"));
    } catch(Exception e){
      showError("Internal problem: " + e);
    }
  }

  public void actionPerformed(ActionEvent evt){
    if(isAlive){
      try{
        Vector areasVector = new Vector();
        for(int i = 0; i < areaCheckboxes.length; i++){
          if(areaCheckboxes[i].getState()){
            areasVector.addElement(areaCheckboxes[i].getLabel());
          }
        }
        String[] areas = new String[areasVector.size()];
        areasVector.copyInto(areas);
        
        Vector conflictsVector = new Vector();
        for(int i = 0; i < periodNames.length; i++){
          for(int j = 0; j < dayNames.length; j++){
            if(conflictCheckboxes[i][j].getState()){
              conflictsVector.addElement
                (new Conflict(dayNames[j], periodNames[i]));
            }
          }
        }
        Conflict[] conflicts = new Conflict[conflictsVector.size()];
        conflictsVector.copyInto(conflicts);
        
        Course[] courses = server.satisfyAnyAndAvoid(areas, conflicts);

        coursesDisplay.removeAll();
        if(courses.length == 0){
          coursesDisplay.add("None found");
        } else {
          for(int i = 0; i < courses.length; i++){
            Course c = courses[i];
            coursesDisplay.add(c.getDepartment() + c.getNumber()
                               + c.getSection() + ", " + c.getDescription()
                               + ", satisfies " + c.getGeneds()
                               + ", meets " + c.getDays() + " "
                               + c.getPeriods());
          }
        }
      } catch(Exception e){
        showError("Internal problem: " + e);
      }
    }
  }
  
  private void showError(String message){
    // using the coursesDisplay for this is a questionable hack
    coursesDisplay.removeAll();
    coursesDisplay.add(message);
    coursesDisplay.add("This applet is now disabled.");
    coursesDisplay.add("To retry, resubmit the request for this web page.");
    isAlive = false;
  }
}