import java.awt.*;
import java.awt.event.*;

import javax.swing.*;
import javax.swing.event.*;

import java.util.*;


public class EmployeeUI extends JFrame implements ActionListener, ItemListener, ListSelectionListener {

  private JLabel statusLabel;
  private JComboBox employeeTypeChoice;
  private JTextField employeeNameField, departmentNameField, supportAreaNameField, schoolNameField, majorNameField, yearField;
  private JLabel professorLabel, studentLabel, supportStaffLabel;
  private JLabel departmentNameLabel, supportAreaLabel, schoolNameLabel, majorNameLabel, yearLabel, tenureLabel, unionLabel;
  private JCheckBox tenureCheckbox, unionCheckbox;
  private JButton addButton;

  private JList employeeList;
  private JTextField hoursField, payRateField;
  private JButton updateButton;
  private JTextArea infoTextArea;

  private EmployeeManager employeeManager;


  public EmployeeUI() {

    super("Java Application");

    setSize(800, 600);

    Container content = getContentPane();

    employeeManager = new EmployeeManager();

    content.setLayout(new BorderLayout());

    statusLabel = new JLabel("Status: ");
    statusLabel.setBackground(new Color(190, 190, 190));
    content.add(statusLabel, BorderLayout.SOUTH);

    JPanel mainPanel = new JPanel();
    mainPanel.setLayout(new GridLayout(1, 2));
    content.add(mainPanel, BorderLayout.CENTER);

      JPanel addUserPanel = new JPanel();
      addUserPanel.setLayout(new BorderLayout());
      addUserPanel.setBackground(new Color(230, 230, 230));

        JPanel labelPanel = new JPanel();
        labelPanel.setLayout(new GridLayout(10, 1));

          labelPanel.add(new JLabel("Type:"));
          labelPanel.add(new JLabel("Name:"));
          professorLabel = new JLabel("Professor:");
          labelPanel.add(professorLabel);
          labelPanel.add(new JPanel());
          supportStaffLabel = new JLabel("Support Staff:");
          labelPanel.add(supportStaffLabel);
          labelPanel.add(new JPanel());
          studentLabel = new JLabel("Student:");
          labelPanel.add(studentLabel);
          labelPanel.add(new JPanel());
          labelPanel.add(new JPanel());
          labelPanel.add(new JPanel());

        addUserPanel.add(labelPanel, BorderLayout.WEST);

        JPanel fieldPanel = new JPanel();
        fieldPanel.setLayout(new GridLayout(10, 1));

          JPanel panel1 = new JPanel();
          panel1.setLayout(new FlowLayout(FlowLayout.LEFT));

            employeeTypeChoice = new JComboBox();
            employeeTypeChoice.addItem("Professor");
            employeeTypeChoice.addItem("Support Staff");
            employeeTypeChoice.addItem("Student");
            employeeTypeChoice.setMaximumRowCount(3);
            employeeTypeChoice.addItemListener(this);
            panel1.add(employeeTypeChoice);

            panel1.add(new JPanel());

          fieldPanel.add(panel1);

          JPanel panel2 = new JPanel();
          panel2.setLayout(new FlowLayout(FlowLayout.LEFT));

            employeeNameField = new JTextField(20);
            panel2.add(employeeNameField);

          fieldPanel.add(panel2);

          JPanel panel3 = new JPanel();
          panel3.setLayout(new FlowLayout(FlowLayout.LEFT));

            departmentNameLabel = new JLabel("Department:");
            panel3.add(departmentNameLabel);

            departmentNameField = new JTextField(20);
            panel3.add(departmentNameField);

          fieldPanel.add(panel3);

          JPanel panel4 = new JPanel();
          panel4.setLayout(new FlowLayout(FlowLayout.LEFT));

            tenureLabel = new JLabel("Tenure");
            panel4.add(tenureLabel);

            tenureCheckbox = new JCheckBox();
            panel4.add(tenureCheckbox);

          fieldPanel.add(panel4);

          JPanel panel5 = new JPanel();
          panel5.setLayout(new FlowLayout(FlowLayout.LEFT));

            supportAreaLabel = new JLabel("Support Area:");
            panel5.add(supportAreaLabel);

            supportAreaNameField = new JTextField(20);
            panel5.add(supportAreaNameField);

          fieldPanel.add(panel5);

          JPanel panel6 = new JPanel();
          panel6.setLayout(new FlowLayout(FlowLayout.LEFT));

            unionLabel = new JLabel("Union");
            panel6.add(unionLabel);

            unionCheckbox = new JCheckBox();
            panel6.add(unionCheckbox);

          fieldPanel.add(panel6);

          JPanel panel7 = new JPanel();
          panel7.setLayout(new FlowLayout(FlowLayout.LEFT));

            schoolNameLabel = new JLabel("School:");
            panel7.add(schoolNameLabel);

            schoolNameField = new JTextField(20);
            panel7.add(schoolNameField);

          fieldPanel.add(panel7);

          JPanel panel8 = new JPanel();
          panel8.setLayout(new FlowLayout(FlowLayout.LEFT));

            majorNameLabel = new JLabel("Major:");
            panel8.add(majorNameLabel);

            majorNameField = new JTextField(20);
            panel8.add(majorNameField);

          fieldPanel.add(panel8);

          JPanel panel9 = new JPanel();
          panel9.setLayout(new FlowLayout(FlowLayout.LEFT));

            yearLabel = new JLabel("Year:");
            panel9.add(yearLabel);

            yearField = new JTextField(20);
            panel9.add(yearField);

          fieldPanel.add(panel9);

          JPanel panel10 = new JPanel();
          panel10.setLayout(new FlowLayout(FlowLayout.LEFT));

            addButton = new JButton("Add");
            addButton.addActionListener(this);
            panel10.add(addButton);

          fieldPanel.add(panel10);

        addUserPanel.add(fieldPanel, BorderLayout.CENTER);

      mainPanel.add(addUserPanel);

      JPanel payUserPanel = new JPanel();
      payUserPanel.setLayout(new BorderLayout());
      payUserPanel.setBackground(new Color(215, 215, 215));

        payUserPanel.add(new JLabel("Employees:"), BorderLayout.NORTH);

        JPanel panel11 = new JPanel();
        panel11.setLayout(new GridLayout(2, 1));

          employeeList = new JList();
          JScrollPane jsp = new JScrollPane(employeeList);
          employeeList.addListSelectionListener(this);
          panel11.add(jsp);

          JPanel panel12 = new JPanel();
          panel12.setLayout(new GridLayout(3, 1));

            JPanel panel13 = new JPanel();
            panel13.setLayout(new FlowLayout(FlowLayout.LEFT));
            panel13.add(new JLabel("Hours Worked:"));

            hoursField = new JTextField(20);
            panel13.add(hoursField);

          panel12.add(panel13);

            JPanel panel14 = new JPanel();
            panel14.setLayout(new FlowLayout(FlowLayout.LEFT));
            panel14.add(new JLabel("Pay Rate:"));

            payRateField = new JTextField(20);
            panel14.add(payRateField);

          panel12.add(panel14);

            JPanel panel15 = new JPanel();
            updateButton = new JButton("Update");
            updateButton.addActionListener(this);
            panel15.add(updateButton);

          panel12.add(panel15);

        panel11.add(panel12);

      payUserPanel.add(panel11, BorderLayout.CENTER);

      infoTextArea = new JTextArea(5, 20);
      infoTextArea.setEditable(false);
      payUserPanel.add(infoTextArea, BorderLayout.SOUTH);

    mainPanel.add(payUserPanel);

    WindowListener wndCloser = new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    };
    addWindowListener(wndCloser);
    setVisible(true);

    enableProfessor(true);
    enableSupportStaff(false);
    enableStudent(false);
  }


  private void refreshUI() {

    // redraw list and its contents (= names of employees)
    Hashtable h = employeeManager.getEmployees();
    String[] names = new String[h.size()];
    int i = 0;
    for (Enumeration e = h.keys(); e.hasMoreElements(); ) {
      names[i] = (String)e.nextElement();
      i++;
    }

    employeeList.setListData(names);

    // clear input fields
    employeeNameField.setText("");
    departmentNameField.setText("");
    tenureCheckbox.setSelected(false);
    schoolNameField.setText("");
    majorNameField.setText("");
    yearField.setText("");
    supportAreaNameField.setText("");
    unionCheckbox.setSelected(false);

    hoursField.setText("");
    payRateField.setText("");
    infoTextArea.setText("");

    statusLabel.setText("");
  }


  public void actionPerformed(ActionEvent e) {

    Object source = e.getSource();

    if (source == addButton) {
      Payable p = null;
      String name = employeeNameField.getText();
      if (name.equals("")) {
        statusLabel.setText("ERROR: Please enter a name");
        return;
      }
      String type = (String)employeeTypeChoice.getSelectedItem();
      if (type.equals("Professor")) {
        if (departmentNameField.getText().equals("")) {
          statusLabel.setText("ERROR: Please enter a department");
          return;
        }
        p = new Professor(name, departmentNameField.getText(), tenureCheckbox.isSelected());
      } else if (type.equals("Support Staff")) {
        if (supportAreaNameField.getText().equals("")) {
          statusLabel.setText("ERROR: Please enter a Support Area");
          return;
        }
        p = new SupportStaff(name, supportAreaNameField.getText(), unionCheckbox.isSelected());
      } else if (type.equals("Student")) {
        if (schoolNameField.getText().equals("")) {
          statusLabel.setText("ERROR: Please enter a school");
          return;
        } else if (majorNameField.getText().equals("")) {
          statusLabel.setText("ERROR: Please enter a major");
          return;
        }
        int year = -1;
        try {
          year = Integer.parseInt(yearField.getText());
        } catch (Exception e2) {
        }
        if (year < 0) {
          statusLabel.setText("ERROR: Please enter a valid year");
          return;
        }
        p = new Student(name, year, schoolNameField.getText(), majorNameField.getText());
      }
      try {
        employeeManager.addEmployee(p);
      } catch (Exception e2) {
        statusLabel.setText("ERROR: " + e2.getMessage());
        return;
      }
      statusLabel.setText("");
      refreshUI();
    } else if (source == updateButton) {
      if (employeeList.getSelectedIndex() == -1) {
        statusLabel.setText("ERROR: Please select an employee");
        return;
      }
      String name = (String)employeeList.getSelectedValue();
      double hours = -1;
      try {
        hours = Double.parseDouble(hoursField.getText());
      } catch (Exception e2) {
        statusLabel.setText("ERROR: Please enter valid Hours Worked");
        return;
      }
      if (!payRateField.getText().equals("")) {
        float pay = -1;
        try {
          pay = Float.parseFloat(payRateField.getText());
        } catch (Exception e2) {
          statusLabel.setText("ERROR: Please enter valid Pay Rate");
          return;
        }
        try {
          employeeManager.payEmployee(name, hours, pay);
        } catch (Exception e2) {
          statusLabel.setText("ERROR: " + e2.getMessage());
          return;
        }
      } else {
        try {
          employeeManager.payEmployee(name, hours);
        } catch (Exception e2) {
          statusLabel.setText("ERROR: " + e2.getMessage());
          return;
        }
      }
      refreshUI();
    }
  }


  public void itemStateChanged(ItemEvent e) {

    if (e.getSource() == employeeTypeChoice) {
      String type = (String)employeeTypeChoice.getSelectedItem();
      if (type.equals("Professor")) {
        enableProfessor(true);
        enableStudent(false);
        enableSupportStaff(false);
      } else if (type.equals("Support Staff")) {
        enableProfessor(false);
        enableStudent(false);
        enableSupportStaff(true);
      } else if (type.equals("Student")) {
        enableProfessor(false);
        enableStudent(true);
        enableSupportStaff(false);
      }
    }
  }


  public void valueChanged(ListSelectionEvent e) {

    String s = (String)employeeList.getSelectedValue();
    Hashtable h = employeeManager.getEmployees();
    if ((s == null) || (!h.containsKey(s))) {
      refreshUI();
      return;
    }
    Payable p = (Payable)h.get(s);
    infoTextArea.setText(p + "\n" + p.getAccount());
  }


  private void enableProfessor(boolean b) {

    professorLabel.setVisible(b);
    departmentNameField.setVisible(b);
    tenureCheckbox.setVisible(b);
    departmentNameLabel.setVisible(b);
    tenureLabel.setVisible(b);
  }


  private void enableStudent(boolean b) {

    studentLabel.setVisible(b);
    schoolNameField.setVisible(b);
    majorNameField.setVisible(b);
    yearField.setVisible(b);
    schoolNameLabel.setVisible(b);
    majorNameLabel.setVisible(b);
    yearLabel.setVisible(b);
  }


  private void enableSupportStaff(boolean b) {

    supportStaffLabel.setVisible(b);
    supportAreaNameField.setVisible(b);
    unionCheckbox.setVisible(b);
    supportAreaLabel.setVisible(b);
    unionLabel.setVisible(b);
  }


  public static void main(String[] args) {

    EmployeeUI employeeUI = new EmployeeUI();
  }
}