import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class intermediatep {
	static String subject;// main variable which contains the subject
							// entered/selected

	public static void main(String[] args) {
		try {
			// create a mysql database connection
			String myDriver = "com.mysql.jdbc.Driver";
			String myUrl = "jdbc:mysql://localhost:3307/quiz";
			Class.forName(myDriver);
			Connection conn = DriverManager.getConnection(myUrl, "root", "");
			String query = "select distinct subject from student";
			Statement st = conn.createStatement();
			ResultSet rs = st.executeQuery(query);
			int ctr = 0, i = 0;
			String sub[];
			while (rs.next()) {
				ctr++;
			}

			sub = new String[ctr];
			while(rs.next()) {
				sub[i] = rs.getString("subject"); //takes only the unique values from the database due to the query sent
				i++;
			}

			JFrame f = new JFrame("Quiz Portal");
			f.setSize(310, 300);
			JLabel l;
			l = new JLabel("Select Subject:\n");
			l.setBounds(50, 25, 100, 20);
			JTextArea t1, t2;
			JScrollPane p;
			t1 = new JTextArea();
			t1.setBounds(140, 25, 100, 20);
			DefaultListModel<String> s = new DefaultListModel<>();

			for (i = 0; i < ctr; i++) {
				s.addElement(sub[i]);
			}

			JList<String> list = new JList<>(s);
			// String j=list.getSelectedValue();

			p = new JScrollPane(list, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
					JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
			p.setBounds(90, 80, 110, 90);

			JButton b1 = new JButton("Start Quiz");

			b1.addActionListener(new ActionListener()

			{

				public void actionPerformed(ActionEvent e) {

					if (list.getSelectedValue() != null)
						subject = list.getSelectedValue().toString();
					else {
						subject = t1.getText();
					}

					// create object for the next panel-menu obj = new menu();
				}
			});
			b1.setBounds(95, 200, 100, 20);

			f.add(l);
			f.add(t1);
			f.add(p);
			f.add(b1);
			f.setLayout(null);
			f.setVisible(true);
			f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		} catch (Exception e) {
			System.err.println("Got an exception!");
			System.err.println(e.getMessage());

		}
	}
}