import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.sql.*;

public class AdvAccessTry extends JFrame implements ActionListener
{
    Container cp;
    JTextField txtUsername,txtPassword,txtChangePass;
    JLabel lblTries,lblWelcome;
    JButton cmdLogin,cmdChangePass,cmdLogout;
    Connection con;
    int check = 3;
    String uName = "Guest";


    public AdvAccessTry()
    {
        super("Login");
        cp = getContentPane();
        cp.setLayout(new FlowLayout());

        lblWelcome = new JLabel("Welcome "+uName);
        cp.add(lblWelcome);

        txtUsername = new JTextField(20);
        txtPassword = new JTextField(20);
        cp.add(txtUsername);
        cp.add(txtPassword);

        lblTries = new JLabel("Remaining Tries: 3");
        cp.add(lblTries);


        cmdLogin = new JButton("Login");
        cp.add(cmdLogin);
        cmdLogin.addActionListener(this);

        cmdLogout = new JButton("Logout");
        cp.add(cmdLogout);
        cmdLogout.addActionListener(this);
        cmdLogout.setEnabled(false);

        txtChangePass = new JTextField(20);
        cp.add(txtChangePass);
        txtChangePass.setEnabled(false);

        cmdChangePass = new JButton("Change Password");
        cp.add(cmdChangePass);
        cmdChangePass.addActionListener(this);
        cmdChangePass.setEnabled(false);
        try
        {
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
            con = DriverManager.getConnection("jdbc:odbc:Trying");
        }
        catch(Exception e)
        {
            JOptionPane.showMessageDialog(this,"Error");
            System.out.println(e+"");
        }

    }
    public void actionPerformed(ActionEvent ae)
    {
        if(ae.getSource() == cmdLogin)
        {
            try
            {
                if(check>0)
                {
                    Statement stmt = con.createStatement();
                    ResultSet rs = stmt.executeQuery("SELECT * FROM Access");
                    int i = 0;
                    while(rs.next())
                    {
                        if(txtUsername.getText().equals(rs.getString("Username")) && txtPassword.getText().equals(rs.getString("Password")))
                        {
                            i=1;
                            uName = txtUsername.getText();
                        }
                    }
                    if(i>0)
                    {
                        JOptionPane.showMessageDialog(this,"Access Granted");
                        check = 3;
                        txtChangePass.setEnabled(true);
                        cmdChangePass.setEnabled(true);
                        lblWelcome.setText("Welcome "+uName);
                        txtUsername.setEnabled(false);
                        txtPassword.setEnabled(false);
                        cmdLogin.setEnabled(false);
                        cmdLogout.setEnabled(true);
                        lblTries.setEnabled(false);
                    }
                    else
                    {
                        JOptionPane.showMessageDialog(this,"Access Denied");
                        check = check-1;
                        txtChangePass.setEnabled(false);
                        cmdChangePass.setEnabled(false);
                        uName = "Guest";
                        lblWelcome.setText("Welcome "+uName);
                        lblTries.setEnabled(true);
                        if(check == 0)
                        {
                            JOptionPane.showMessageDialog(this,"You used all three tries");
                            txtUsername.setEnabled(false);
                            txtPassword.setEnabled(false);
                            cmdLogin.setEnabled(false);
                            lblTries.setText("Tries Remaining: "+check);
                            lblTries.setEnabled(false);
                        }
                    }
                    lblTries.setText("Tries Remaining: "+check);
                }
            }
            catch(Exception e)
            {
                System.out.println(e.toString());
                JOptionPane.showMessageDialog(this,"Error");
            }

        }
        if(ae.getSource() == cmdLogout)
        {
            JOptionPane.showMessageDialog(this,"Logged out from "+uName);
            uName = "Guest";
            lblWelcome.setText("Welcome "+uName);
            txtUsername.setEnabled(true);
            txtPassword.setEnabled(true);
            cmdLogin.setEnabled(true);
            cmdLogout.setEnabled(false);
            txtChangePass.setText("");
            txtUsername.setText("");
            txtPassword.setText("");
            txtChangePass.setEnabled(false);
            cmdChangePass.setEnabled(false);
            lblTries.setEnabled(true);

        }
        if(ae.getSource() == cmdChangePass)
        {
            try
            {
                if((txtChangePass.getText()).length()>0)
                {
                Statement stmt= con.createStatement();
                int i = stmt.executeUpdate("UPDATE Access SET Password = '"+txtChangePass.getText()+"' WHERE Username = '"+uName+"'");
                JOptionPane.showMessageDialog(this,"Password Changed");
                txtPassword.setText(txtChangePass.getText());
                txtChangePass.setText("");

                }
                else
                    JOptionPane.showMessageDialog(this,"Please enter a Password");

            }
            catch(Exception e)
            {
                JOptionPane.showMessageDialog(this,"Error Changing Password");
                System.out.println(e+"");
            }
        }
    }
    public static void main(String args[])
    {
        AdvAccessTry at = new AdvAccessTry();
        at.setSize(300,300);
        at.setVisible(true);
    }
}