package cs132.markov;

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.net.URL;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Random;
import java.util.LinkedList;
import java.util.Scanner;
import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.ScrollPaneConstants;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;

public class MarkovTextApplet extends JApplet implements ActionListener {
	JButton loadButton;
	JButton generateButton;
	JTextArea trainArea;
	JTextArea textArea;
	JTextField orderTextField;
	JTextField urlTextField;
	Integer order;
	
	private void CreateWordGUI() {
		resize(800, 400);

		/* Name label and textfield */
		JLabel urlLabel = new JLabel("URL");
		urlTextField = new JTextField(60);
		urlTextField.setText("http://www.cs.umd.edu/class/spring2007/cmsc132/Projects/lamb.txt");
		urlTextField.addActionListener(this);
		
		JLabel orderLabel = new JLabel("Markov Order");
		orderTextField = new JTextField(3);
		orderTextField.setText("1");
		orderTextField.addActionListener(this);
		
		/* Adding buttons */
		loadButton = new JButton("Load URL training data");
		loadButton.addActionListener(this);
		
		generateButton = new JButton("Generate Markov text");
		generateButton.addActionListener(this);
		
		/* Text Area for training data */
		JLabel trainLabel = new JLabel("Training");
		trainArea = new JTextArea(6,50);
		trainArea.setEditable(true);
		trainArea.setLineWrap(true);
		trainArea.setWrapStyleWord(true);
		
		JScrollPane scrollPane = new JScrollPane(trainArea,
				ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
				ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
		
		/* Text area to type info */
		JLabel textLabel = new JLabel("Markov");
		textArea = new JTextArea(6,50);
		textArea.setEditable(false);
		textArea.setLineWrap(true);
		textArea.setWrapStyleWord(true);
		
		JScrollPane scrollPane2 = new JScrollPane(textArea,
				ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
				ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);

		// Lay out the GUI.
		BorderLayout layout = new BorderLayout();
		Container contentPane = getContentPane();
		contentPane.setLayout(layout);

		JPanel p1 = new JPanel(new BorderLayout());
		JPanel t1 = new JPanel(new FlowLayout());
		t1.add(urlLabel);
		t1.add(urlTextField);
		t1.add(loadButton);
		p1.add(t1,BorderLayout.NORTH);
		p1.add(scrollPane,BorderLayout.CENTER);
		p1.add(trainLabel,BorderLayout.LINE_START);
		
		JPanel p2 = new JPanel(new BorderLayout());
		JPanel t2 = new JPanel(new FlowLayout());
		t2.add(orderLabel);
		t2.add(orderTextField);
		t2.add(generateButton);
		p2.add(t2,BorderLayout.NORTH);
		p2.add(scrollPane2,BorderLayout.CENTER);
		p2.add(textLabel,BorderLayout.LINE_START);

		contentPane.add(p1, BorderLayout.NORTH);
		contentPane.add(p2, BorderLayout.CENTER);
	}

	// Called when this applet is loaded into the browser.
	@Override
	public void init() {

		// Execute a job on the event-dispatching thread:
		// creating this applet's GUI.
		try {
			SwingUtilities.invokeLater(new Runnable() {
				public void run() {
					CreateWordGUI();
				}
			});
		} catch (Exception e) {
			System.err.println("MarkovTextApplet didn't successfully complete");
		}

	}

	private static void parseWords(String s, List<String> words)
	{
		s = s.trim();
		List<String> theseWords = Arrays.asList(s.split("[ \t\n\r]+"));
		words.addAll(theseWords);
	}

	public void actionPerformed(ActionEvent e) {
		String trainStr = new String();

		String orderStr = orderTextField.getText();
		order = Integer.parseInt(orderStr);
		if ((order < 1) || (order > 100)) {
			order = 1;
			orderTextField.setText(order.toString());
		}

		if ((e.getSource() == loadButton) || (e.getSource() == urlTextField)) {
			trainStr = trainURL();
			if (trainStr != null) {
				trainArea.selectAll();
				trainArea.setText(trainStr);
			}
		}
	   	else if (e.getSource() == trainArea) {

	   	}
	   	else if (e.getSource() == generateButton) {
	   		String output = new String();
	   		trainArea.selectAll();
	   		trainStr = trainArea.getText();
	   		if (trainStr == null) {
	   			output = "No training text";
	   		}
	   		else {
	   			LinkedList<String> l = new LinkedList<String>();
	   			parseWords(trainStr,l);
	   			if ((trainStr.length() == 0) || (l.size() == 0)) {
	   				output = "No training text";
	   			}
	   			else {
	   				MarkovText mgen = new MarkovText(order);
	   				mgen.updateMarkovTransitions(l.iterator());
	   				Iterator<String> markovIterator = mgen.markovIterator(new Random());
	   				output = PublicTests.makeString(Words.characters(markovIterator));
	   			}
	   		}
	   		textArea.selectAll();
	   		textArea.setText(output);
	   	}
	}

	public String trainURL() {
		String val = new String();
		String urlStr = urlTextField.getText();

		URL userUrl = null;
		boolean UrlOnError = false;

		// Transform the String to a real URL
		try {
			userUrl = new URL(urlStr);
		} catch (Exception exc) {
			UrlOnError = true;
		}
		if (!UrlOnError && (userUrl != null)) {
			try {
				Scanner sc = new Scanner(userUrl.openStream());
				val = new String();
				while (sc.hasNextLine()) {
					val = val+sc.nextLine()+" ";
				}
			} catch (Exception exc) {
				UrlOnError = true;
			}

		}
		if (UrlOnError) {
			trainArea.selectAll();
			trainArea.setText("Problem reading URL: " + urlStr);
			val = null;
		} 
		return val;
	}
	
	public static void main(String[] args) {
		javax.swing.SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new MarkovTextApplet();
			}
		});
	}

	/* Static block for feel and look */
	/* Comment this block out and see how the feel and look changes */
	/* You can also try this experiment in a Mac */

	static {
		try {
			UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
		} catch (Exception e) {
			System.out.println(e.getMessage());
		}
	}
}