import java.applet.Applet;

import java.awt.Label;

import java.io.BufferedReader;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.IOException;

import java.net.URL;

import java.net.MalformedURLException;





/**

 * A simple applet that will to 'vote' for something on the web by

 * requesting a preset URL. The vote url is hard-coded so that 'other'

 * people cannot use this very same applet for the same 'election' to their

 * own use, e.g. steal a vote from me. 

 *

 * <p>Possible parameters are:<br><ol>

 * <li>Number of threads that will vote simultaneously: <tt>threads</tt>

 * </ol>

 *

 * <p>This applet will not circumvent 'smart' checks on the 

 * server side. But it will be a lesson to those script kiddies that thought

 * they didn't need to check if 'someone' already has cast a vote. </p>

 *

 * @author Jeroen Pulles

 */

public class Vote extends Applet

{

	private int          m_count; // totals

	private String       m_voteurl;

	private Label        m_numLabel;

	private VoteWorker[] m_workers;

	

	public Vote()

	{

		m_count = 0;

		m_workers = new VoteWorker[5];

		m_numLabel = new Label("0");

		// better off to put stuff in init() instead.

	}

	



	/**

	 * The applet is loaded, or reloaded. 

	 */

	public void init()

	{

		m_voteurl = getParameter("url");

		m_numLabel.setText(String.valueOf(m_count));

		m_numLabel.setLocation(8,8);

		add(m_numLabel);

		validate();

	}



	

	public void start()

	{

		System.out.println("Vote version 0.1");

		showStatus("Vote applet starting to vote.");

		try {

			for (int i = 0; i < m_workers.length; i++) {

				m_workers[i] = new VoteWorker(

					m_voteurl, this);

			}

		} catch (MalformedURLException e) {

			showStatus(

				"Malformed URL: " + e.getMessage());

			System.out.println(

				"Malformed URL: " + e.getMessage());

		} catch (SecurityException e) {

			System.out.println(

				"Security Exception: " + e.getMessage());

		}

		

	}

	

	

	public void stop()

	{

		// stop all voteworkers:

		for (int i = 0; i < m_workers.length; i++) {

			VoteWorker v = m_workers[i];

			if (v != null) {

				v.stop();

			}

		}

		m_count = 0;

		showStatus("Vote applet stopped.");

	}



	

	public void destroy()

	{

	}





	public synchronized void incrementCount()

	{

		m_numLabel.setText(String.valueOf(++m_count));

	}



	

	/** 

	 * Does the work of voting, by making a HTTP GET request to the URL.

	 */

	private class VoteWorker implements Runnable

	{

		private URL            m_url;

		private Vote           m_panel;

		private StringBuffer   m_result;

		private int            m_total;

		private Thread         m_VoteThread;



		public VoteWorker(String url, Vote vw) throws MalformedURLException

		{

			m_url = new URL(url);

			m_panel = vw;

			m_result = new StringBuffer();

			m_total = 0;

			m_VoteThread = new Thread(this, "VoteWorker");

			m_VoteThread.start();

		}

		

		public void run()

		{

			String line = "--->"; 

			BufferedReader in = null;

			Thread currentThread = Thread.currentThread();

			while (currentThread == m_VoteThread) {

				System.out.println("GET " + m_url.toString());

				try {

					in = new BufferedReader(

						new InputStreamReader(

							m_url.openStream())

						);

					while ((line = in.readLine()) != null) {

						m_result.append(line);

						// TODO ignore response after a few lines :-)

					}

					m_total++;

					m_panel.incrementCount();

				} catch (IOException e) {

					System.out.println(e.getMessage());

					// TODO show status message

				} catch (ClassCastException c) {

					System.out.println(c.getMessage());

				}

				try {

					in.close();

				} catch (IOException e) {

				} catch (NullPointerException e) {

				}

				try {

					Thread.sleep(1000);

				} catch (InterruptedException e) {

				}

			}

		}



		public String getResponse()

		{

			return m_result.toString();

		}



		public synchronized void stop()

		{

			m_VoteThread = null;

		}



		public int total()

		{	

			return m_total;

		}

	}

	

} // Vote.java