import org.hibernate.*;
import org.hibernate.cfg.Configuration;
import org.hibernate.cfg.Environment;

import javax.swing.*;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * User: Alan P. Sexton
 * Date: 26-Jan-2007
 * Time: 09:42:00
 */
public class Main
{
    private static final Log LOG = LogFactory.getLog(Main.class);
    private static SessionFactory sessions = null;

    public static void main(String[] args)
    {
        boolean createDb = false;
        if (args.length == 1 && "create".equals(args[0].toLowerCase()))
            createDb = true;
        else if (args.length != 0)
        {
            System.err.println("Usage: java Main [create]");
            System.exit(1);
        }

        Configuration cfg = new Configuration();
        try
        {
            cfg.addClass(Message.class);


            String username = cfg.getProperty("hibernate.connection.username");

            // get the username and password via a Swing JDialog box
            String[] userNamePassword = getUsernamePassword(username);
            if (userNamePassword == null)
            {
                LOG.info("No valid user name/password pair was entered");
                System.exit(1) ;
            }
            else
            {
                cfg.setProperty("hibernate.connection.username", userNamePassword[0]);
                cfg.setProperty("hibernate.connection.password", userNamePassword[1]);
            }
            if (createDb)
            {
                LOG.info("(Re-)creating the database: old data will be destroyed");
                cfg.setProperty(Environment.HBM2DDL_AUTO, "create");
            }

            LOG.debug("Building the Session Factory");
            sessions = cfg.buildSessionFactory();

            LOG.debug("About to add message");
            String msgText = "Hello World";
            Long id ;
            id = addMessage(msgText);
            LOG.debug("Added Message");

            LOG.debug("Message saved to database");
            System.out.println(getMessagesAsString()) ;

            String[] msgs = {"Take me to your leader...", "...(please)"};
            updateMessage(id, "Greetings Earthling", msgs);

            LOG.debug("Message Updated");
            System.out.println(getMessagesAsString()) ;
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        System.exit(0);
    }


    private static Long addMessage(String msgText)
            throws HibernateException
    {
        Session session = sessions.openSession();
        Transaction tx = null;
        Message message = null;
        try
        {
            tx = session.beginTransaction();

            message = new Message(msgText);
            // At this point, Message is "Transient"
            session.save(message);
            // Now it is "Persistent"

            tx.commit();
        }
        catch (HibernateException e)
        {
            if (tx != null)
                tx.rollback();
            throw e;
        }
        finally
        {
            session.close();
        }
        // Note that the following works even though message is no longer associated with a session,
        // i.e., it is "Detached":
        return message.getId();
    }

    private static String getMessagesAsString()
            throws HibernateException
    {
        StringBuilder retMessages = new StringBuilder();
        Session session = sessions.openSession();
        Transaction tx = null;
        try
        {
            tx = session.beginTransaction();


            List messages = session.createQuery("from Message as m order by m.id asc"). list();
            System.out.println("Number of messages found: " + messages.size());
            for (Object message : messages)
            {
                Message m = (Message) message;
                retMessages.append(String.format("%d:%s%n", m.getId(), m.getText()));
            }


            tx.commit();
        }
        catch (HibernateException e)
        {
            if (tx != null)
                tx.rollback();
            throw e;
        }
        finally
        {
            session.close();

        }
        return retMessages.toString() ;
    }

    private static void updateMessage(Long msgID, String msgText, String[] msgTexts)
            throws HibernateException
    {
        Session session = sessions.openSession();
        Transaction tx = null;
        try
        {
            tx = session.beginTransaction();


            Message message = (Message) session.load(Message.class, msgID);
            message.setText(msgText);
            for (String msgText1 : msgTexts)
            {
                Message nextMessage = new Message(msgText1);
                message.setNextMessage(nextMessage);
                message = nextMessage;
            }


            tx.commit();
        }
        catch (HibernateException e)
        {
            if (tx != null)
                tx.rollback();
            throw e;
        }
        finally
        {
            session.close();

        }
    }

    /**
     * Shows a dialog box for the user to enter a password and a username. Note that using this
     * method means that the application must be terminated by calling <code>System.exit(0)</code>
     * to ensure that all the Swing threads created by this method are terminated and the JVM
     * can exit.
     *
     * @param initialUsername the <code>String</code> that the username field in the dialog
     *                        should be initialised to.
     * @return <code>null</code> if the user clicked on the <code>CANCEL</code> button or on
     *         the window close button. Otherwise an array of 2 <code>String</code>s is returned.
     *         The first <code>String</code> in the array is the username entered, the second
     *         is the password.
     */
    private static String[] getUsernamePassword(String initialUsername)
    {
        JTextField username = new JTextField((initialUsername == null) ? "" : initialUsername, 20);
        JPasswordField password = new JPasswordField(20);

        final Object[] fields = {"Enter your database username:",
                                 username,
                                 "Enter your database password:",
                                 password
                                 };
        JOptionPane pane = new JOptionPane(fields,
                                           JOptionPane.QUESTION_MESSAGE,
                                           JOptionPane.OK_CANCEL_OPTION,
                                           null);
        JDialog d = pane.createDialog(null, "Database Access");
        d.setVisible(true);

        Integer returnValue =  (Integer) pane.getValue();
        d.dispose();

        if (returnValue == null || returnValue != JOptionPane.OK_OPTION)
            return null;
        return new String[]{username.getText(), new String(password.getPassword())};
    }
}