/*
This file is part of the algoviz@vt collection of algorithm
visualizations.

This program is free software: you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation, either version 3
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this distribution. If not, see
<http://www.gnu.org/licenses/>.
*/

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;

import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.ButtonGroup;
import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.JTextPane;
import javax.swing.text.BadLocationException;
import javax.swing.text.DefaultStyledDocument;
import javax.swing.text.Style;
import javax.swing.text.StyleConstants;
import javax.swing.text.StyleContext;

/**
 * This is the main class behind the BST applet. It has a feedback panel, main
 * panel, and control panel. The main panel holds a <code>TreePanel</code>
 * which controls manipulation of the BST itself.
 * 
 * @see TreePanel
 * @author Andrew Whitaker (aawhitak@vt.edu)
 */
public class TreeApplet extends JApplet
{
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    /*
     * Styles for feedback. INTERMEDIATE_STYLE = The style of an intermediate
     * step in an operation. FINAL_STYLE = The style of the last step of an
     * operation (could come in handy, not currently used). UNFOCUSED_STYLE =
     * The style of an unfocused step thats displayed in feedback. For example,
     * this style would be applied after a state is stepped over.
     */
    public static Style INTERMEDIATE_STYLE, MAIN_STYLE, UNFOCUSED_STYLE;
    private DefaultStyledDocument doc;
    private Container content;
    /* The main components of the TreeApplet. */
    private JPanel controlsPanel, feedbackPanel;
    /* Radio buttons the user will use to select an operation */
    private JRadioButton findRadioButton, deleteRadioButton, insertRadioButton;
    private JTextPane feedback;
    /* User-input text field */
    private JTextField insertTextField;
    /*
     * Not used, but could be used to display a message to the user in the
     * controls panel
     */
    private JLabel message;
    /* Control buttons */
    private JButton startButton, next, previous, first, last;
    /*
     * Represents the current step number while iterating through a BST
     * operation.
     */
    private int stepNum;
    private int docPos;
    /* TreePanel holding/controlling the BST */
    private TreePanel treePanel;

    /**
     * Creates a new TreeApplet. The applet has a BorderLayout with the
     * TreePanel in the center, feedback to the right, and controls at the
     * bottom.
     */
    public TreeApplet()
    {
	super();
	/* Setup styles and other things necessary for feedback. */
	initializeFeedback();
	/* Set up applet */
	content = new Container();
	content.setLayout(new BorderLayout());

	/* Controls */
	controlsPanel = new JPanel();
	controlsPanel.setLayout(new BoxLayout(controlsPanel, BoxLayout.X_AXIS));
	ButtonGroup modeGroup = new ButtonGroup();
	insertRadioButton = new JRadioButton("Insert");
	insertRadioButton.setBackground(Color.WHITE);
	insertRadioButton.addActionListener(new RadioButtonListener());
	findRadioButton = new JRadioButton("Find");
	findRadioButton.addActionListener(new RadioButtonListener());
	deleteRadioButton = new JRadioButton("Delete");
	deleteRadioButton.setBackground(Color.WHITE);
	deleteRadioButton.addActionListener(new RadioButtonListener());
	findRadioButton.setBackground(Color.WHITE);
	modeGroup.add(findRadioButton);
	modeGroup.add(deleteRadioButton);
	modeGroup.add(insertRadioButton);
	JPanel modePanel = new JPanel();
	modePanel.setLayout(new BoxLayout(modePanel, BoxLayout.Y_AXIS));
	modePanel.add(findRadioButton);
	modePanel.add(deleteRadioButton);
	modePanel.add(insertRadioButton);
	modePanel.setBackground(Color.WHITE);
	controlsPanel.add(modePanel);
	controlsPanel.setBackground(Color.WHITE);
	controlsPanel.setBorder(BorderFactory.createEtchedBorder());
	content.add(controlsPanel, BorderLayout.SOUTH);

	/* Text field and buttons */
	JPanel inputPanel = new JPanel();
	JPanel stepsPanel = new JPanel(new FlowLayout());
	inputPanel.setLayout(new BoxLayout(inputPanel, BoxLayout.Y_AXIS));
	insertTextField = new JTextField(10);
	stepsPanel.add(insertTextField);
	startButton = new JButton("Start");
	startButton.setEnabled(false);
	insertTextField.setEnabled(false);
	stepsPanel.add(startButton);
	next = new JButton(">");
	previous = new JButton("<");
	first = new JButton("<<");
	last = new JButton(">>");

	stepsPanel.add(first);
	stepsPanel.add(previous);
	stepsPanel.add(next);
	stepsPanel.add(last);
	first.setEnabled(false);
	previous.setEnabled(false);
	next.setEnabled(false);
	last.setEnabled(false);
	JPanel messagePanel = new JPanel();
	message = new JLabel();
	message.setForeground(Color.RED);
	messagePanel.add(message);
	inputPanel.add(stepsPanel);
	inputPanel.add(messagePanel);

	controlsPanel.add(inputPanel);
	/* Add Listeners */
	startButton.addActionListener(new ControlButtonListener());
	next.addActionListener(new ControlButtonListener());
	previous.addActionListener(new ControlButtonListener());
	first.addActionListener(new ControlButtonListener());
	last.addActionListener(new ControlButtonListener());

	/* End Controls */

	/* Feedback */
	feedbackPanel = new JPanel();
	feedbackPanel.setLayout(new BoxLayout(feedbackPanel, BoxLayout.Y_AXIS));
	JScrollPane scrollPanel = new JScrollPane(feedback);
	scrollPanel.setPreferredSize(new Dimension(150, 700));
	feedbackPanel.setBackground(Color.WHITE);
	JPanel labelPanel = new JPanel(new FlowLayout());
	labelPanel.add(new JLabel("Step History"));
	labelPanel.setBackground(Color.WHITE);
	feedbackPanel.add(labelPanel);
	feedbackPanel.add(scrollPanel);
	content.add(feedbackPanel, BorderLayout.EAST);
	setContentPane(content);
	/* End Feedback */

	/* Makes scrolling for large BST's possible */
	treePanel = new TreePanel(this);
	treePanel.setPreferredSize(new Dimension(2000, 1200));
	JScrollPane scroll = new JScrollPane(treePanel);
	// scroll.setPreferredSize(new Dimension(1200, 1200));
	content.add(scroll, BorderLayout.CENTER);

    }

    /**
     * Sets up styles and the Document that handles feedback. See the
     * <code>Document</code> javadocs for more information on how Documents in
     * Java work.
     */
    private void initializeFeedback()
    {
	StyleContext sc = new StyleContext();
	doc = new DefaultStyledDocument(sc);
	docPos = 0;
	feedback = new JTextPane(doc);
	feedback.setEditable(false);

	INTERMEDIATE_STYLE = sc.addStyle("Intermediate", null);
	INTERMEDIATE_STYLE
		.addAttribute(StyleConstants.Foreground, Color.ORANGE);

	INTERMEDIATE_STYLE.addAttribute(StyleConstants.LeftIndent, 1.2);

	MAIN_STYLE = sc.addStyle("Final", null);
	MAIN_STYLE.addAttribute(StyleConstants.Foreground, Color.BLUE);

	MAIN_STYLE.addAttribute(StyleConstants.LeftIndent, 1.2);

	UNFOCUSED_STYLE = sc.addStyle("Unfocused", null);
	UNFOCUSED_STYLE.addAttribute(StyleConstants.Foreground, Color.GRAY);

	UNFOCUSED_STYLE.addAttribute(StyleConstants.LeftIndent, 1.2);

    }

    /**
     * Focuses a state in the current BST operation.
     * 
     * @see BasicState.java
     * @param s
     *                The state to focus.
     */
    public void focusState(State s)
    {
	System.out.println("FOCUSING " + s.getNode().toString());
	String docText = new String(), text = s.getText();

	GraphicalNode currentNode = s.getNode();
	System.out.println(currentNode);
	/*
	 * If this is the first time the node will be displayed, animate it in.
	 * For more information about animation, see TreePanel.java
	 */
	if (currentNode.isHidden())
	{
	    treePanel.animateNodeEntry(currentNode);
	    // currentNode.select();
	    // treePanel.repaint();
	}
	else
	{
        		currentNode.select();
        		treePanel.setRepaint(true);
        		treePanel.setRecalculateTree(false);
        		treePanel.repaint();

	}
	try
	{
	    docText = doc.getText(0, doc.getLength());
	}
	catch (BadLocationException e)
	{
	    // TODO Auto-generated catch block
	    e.printStackTrace();
	}
	String workingText = docText.substring(docPos);
	if (workingText.lastIndexOf(text) != -1)
	{
	    doc.setCharacterAttributes(docText.lastIndexOf(text),
		    text.length(), INTERMEDIATE_STYLE, true);
	}
	else
	{
	    try
	    {
		doc.insertString(doc.getLength(), s.getText(),
			INTERMEDIATE_STYLE);
	    }
	    catch (BadLocationException e1)
	    {
		// TODO Auto-generated catch block
		e1.printStackTrace();
	    }
	}
    }

    /**
     * Unfocuses a state. Changes the color of the node and changes the selected
     * text in the feedback area.
     * 
     * @see BasicState.java
     * 
     * @param s
     *                The State to focus
     */
    public void unfocusState(State s)
    {
	System.out.println("UNFOCUSING: " + s.getNode().toString());
	String docText = new String(), text = s.getText();
	System.out.println(s.getNode());
	/* Unselect the node */
	s.getNode().unSelect();
	try
	{
	    docText = doc.getText(0, doc.getLength());
	}
	catch (BadLocationException e)
	{
	    // TODO Auto-generated catch block
	    e.printStackTrace();
	}
	doc.setCharacterAttributes(docText.lastIndexOf(text), text.length(),
		UNFOCUSED_STYLE, true);
    }

    /**
     * Listens to RadioButton clicks. This is only used when the application
     * initially loads. At first, no radiobuttons are selected, but when the
     * user selects one, the input text field should become visible, and so
     * should the "Start" button.
     * 
     * @author Andrew Whitaker (aawhitak@vt.edu)
     * 
     */
    public class RadioButtonListener implements ActionListener
    {
	public void actionPerformed(ActionEvent e)
	{
	    startButton.setEnabled(true);
	    insertTextField.setEnabled(true);
	}

    }

    /**
     * Internal class that handles control buttons (start, first, end, last,
     * prev).
     * 
     * @author Andrew Whitaker (aawhitak@vt.edu)
     * 
     */
    public class ControlButtonListener implements ActionListener
    {
	public void actionPerformed(ActionEvent e)
	{
	    JButton src = (JButton) e.getSource();
	    /* Handle a start button click */
	    if (src == startButton)
	    {
		if (insertTextField.getText() != "")
		{
		    ArrayList<State> l = treePanel.getStateList();
		    if (l.size() > 0)
		    {
			for (int n = 0; n < l.size(); n++)
			{
			    unfocusState(l.get(n));
			}
		    }
		    Integer i = new Integer(insertTextField.getText());
		    if (insertRadioButton.isSelected())
		    {
			treePanel.insert(i);
			try
			{
			    doc
				    .insertString(doc.getLength(),
					    "Operation: Insert " + i + "\n",
					    MAIN_STYLE);
			}
			catch (BadLocationException e1)
			{
			    // TODO Auto-generated catch block
			    e1.printStackTrace();
			}
		    }
		    else if (findRadioButton.isSelected())
		    {
			treePanel.find(i);
			try
			{
			    doc.insertString(doc.getLength(),
				    "Operation: Find " + i + "\n", MAIN_STYLE);
			}
			catch (BadLocationException e1)
			{
			    // TODO Auto-generated catch block
			    e1.printStackTrace();
			}
		    }
		    insertTextField.setText("");
		    /* Reset the start number */
		    stepNum = -1;
		    docPos = doc.getLength();
		    /* Set the buttons correctly */
		    next.setEnabled(true);
		    last.setEnabled(true);
		    previous.setEnabled(false);
		    first.setEnabled(false);
		}
	    }
	    /* Handle a next button click */
	    else if (src == next)
	    {
		stepNum++;
		previous.setEnabled(true);
		first.setEnabled(true);
		ArrayList<State> list = treePanel.getStateList();
		State s = list.get(stepNum);

		System.out.println("size: " + list.size());
		System.out.println("step: " + stepNum);

		if (stepNum > 0)
		{
		    System.out.println("unfocusing state " + (stepNum - 1));
		    unfocusState(list.get(stepNum - 1));

		}
		focusState(s);

		if (stepNum == list.size() - 1)
		{
		    last.setEnabled(false);
		    next.setEnabled(false);
		    startButton.setEnabled(true);
		}


	    }
	    /* Handle a previous button click */
	    else if (src == previous)
	    {
		ArrayList<State> list = treePanel.getStateList();
		unfocusState(list.get(stepNum));
		stepNum--;
		if (stepNum == 0)
		{
		    first.setEnabled(false);
		    previous.setEnabled(false);
		}
		next.setEnabled(true);
		last.setEnabled(true);
		State s = list.get(stepNum);
		
		focusState(s);
		
		System.out.println("previous");
		System.out.println("size: " + list.size());
		System.out.println("step: " + stepNum);
	    }
	    /* Handles when the first ('<<') button is pressed */
	    else if (src == first)
	    {
		// Count down from the current step number and
		while (previous.isEnabled())
		{
		    // Programmatically hammer down the prev button
		    // to go back all the way.
		    previous.doClick();
		}
		// Reset the step number.
	    }
	    else if (src == last)
	    {
		// See "first" button action for details.
		while (next.isEnabled())
		{
		    System.out.println("CLICK>>");
		    next.doClick();
		}
	    }
	}
    }

}