/*
 * @(#)SetBuilderExerciseApplet.java	0.0.2 99/08/10
 *
 * Copyright (c) 1999 by Willie Wheeler.  All rights reserved.
 */
package stats.exercises;

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import java.util.*;
import javax.help.*;
import javax.swing.*;
import exercise.*;
import stats.*;

/**
 * Exercise applet for set builder exercises.
 * <p>
 * Known bugs:
 * <ul>
 *   <li>We need to remove table model listeners when internal frames are
 *       closed, or else the listeners will not be garbage collected.
 *	 Try adding <tt>println()</tt>'s to a event callback to see what is
 *	 happening.
 *   <li>Under appletviewer, the help system throws exceptions when trying
 *       to paint an image onto the content view.  This does not occur when
 *       running the applet in a browser equipped with the Java plug-in.
 * </ul>
 *
 * @version	0.0.2 08/10/99
 * @author	Willie Wheeler
 */
public class SetBuilderExerciseApplet extends ExerciseApplet
    implements ActionListener {

    /** @serial */
    protected JDesktopPane		desktopPane;

    /** @serial */
    protected SetBuilderExercise	exercise;

    /** @serial */
    protected SetBuilder		builder;

    /** @serial */
    protected Tabulator			tabulator;

    /** @serial */
    protected int			chartFrameX = CHART_FRAME_X_MIN;

    /** @serial */
    protected int			chartFrameY = CHART_FRAME_Y_MIN;

    // Action commands
    protected static final String	SUBMIT = "submit";
    protected static final String	EXIT = "exit";
    protected static final String	ADD_BAR = "add bar";
    protected static final String	ADD_PIE = "add pie";
    protected static final String	ADD_MULTIPLE_BARS = "add multi bars";
    protected static final String	ADD_MULTIPLE_PIES = "add multi pies";
    protected static final String	HELP_COURSEWARE = "help courseware";
    protected static final String	HELP_ABOUT = "help about";

    // Fields for managing placement of chart frames.
    protected static final int		CHART_FRAME_X_MIN = 420;
    protected static final int		CHART_FRAME_X_MAX = 600;
    protected static final int		CHART_FRAME_Y_MIN = 10;
    protected static final int		CHART_FRAME_Y_MAX = 400;

    public void init() {
	super.init();			// Map to exercise servlet.
	ConcretePLAF.install();		// Install the Concrete PLAF.
	this.desktopPane = new JDesktopPane();

	// Install the builder.
	String exerciseID = getParameter("exercise_id");
	this.exercise = (SetBuilderExercise)requestExercise(exerciseID);
	this.builder =
	    new SetBuilder(exercise.getVariables(), exercise.getAtoms());
	JInternalFrame builderFrame =
	    new JInternalFrame("Set Builder", true, true, true, true);
	builderFrame.getContentPane().add(builder);
	builderFrame.setBounds(10, 10, 400, 550);
	desktopPane.add(builderFrame);

	this.tabulator = new Tabulator(builder.getData());
	installInstructions();

	// Frame the desktop pane, and add a menu bar to the frame.
	JFrame desktopFrame = new JFrame("Set Builder Exercise");
	desktopFrame.setJMenuBar(buildMenuBar());
	desktopFrame.setContentPane(desktopPane);
	desktopFrame.setBounds(0, 0, 650, 650);
	desktopFrame.setVisible(true);
    }

    /** Helper method for init().  Installs instructions panel. */
    protected void installInstructions() {
	JPanel panel = new JPanel();
	panel.setLayout(new GridBagLayout());
	GridBagConstraints gbc = new GridBagConstraints();
	panel.setBackground(Color.white);

	JTextArea textArea = new JTextArea("Build a set as follows:\n");
	Vector constraints = exercise.getConstraints();
	for (int i = 0; i < constraints.size(); i++) {
	    SetBuilderExercise.Constraint constraint =
		(SetBuilderExercise.Constraint)constraints.get(i);
	    textArea.append("\n  " + constraint);
	}
	textArea.append("\n\nThen submit your solution.");
	textArea.setFont(new Font("SansSerif", Font.PLAIN, 12));
	textArea.setEditable(false);
	gbc.gridy = 0;
	gbc.insets = new Insets(5, 5, 5, 5);
	panel.add(textArea, gbc);

	JButton button = new JButton("Submit solution");
	button.setActionCommand(SUBMIT);
	button.addActionListener(this);
	gbc.gridy = 1;
	gbc.insets = new Insets(0, 5, 5, 5);
	panel.add(button, gbc);

	JInternalFrame fr = new JInternalFrame();
	fr.putClientProperty("JInternalFrame.isPalette", Boolean.TRUE);
	fr.getContentPane().add(panel);
	fr.setLocation(420, 350);
	fr.pack();
	desktopPane.add(fr, JDesktopPane.PALETTE_LAYER);
    }

    /** Helper method for init().  Builds exercise menu bar. */
    protected JMenuBar buildMenuBar() {

	// Step 1.  Build icons for chart menu.
	String base = "resources/images/icons/";
	Icon[] icons = new ImageIcon[2];
	try {
	    icons[0] =
		new ImageIcon(new URL(getCodeBase(), base + "hist_icon.gif"));
	    icons[1] =
		new ImageIcon(new URL(getCodeBase(), base + "pie_icon.gif"));
	} catch (MalformedURLException e) { System.out.println(e); }

	// Step 2.  Build courseware help system and help listener.
	CSH.DisplayHelpFromSource helpListener = null;
	try {
	    URL hsURL = new URL(getCodeBase(), "resources/help/cwHS.hs");
	    HelpSet hs = new HelpSet(null, hsURL);
	    HelpBroker hb = hs.createHelpBroker();
	    helpListener = new CSH.DisplayHelpFromSource(hb);
	} catch (Exception e) { e.printStackTrace(); }

	// Step 3.  Use the icons and help system to build the menu bar.
	JMenuBar bar = new JMenuBar();
	JMenu menu;

	// Step 3.1.  Build "File" menu.
	menu = buildMenu("File", 'f', new String[] { "Exit" },
        new char[] { 'x' }, new String[] { EXIT }, this, bar);
	menu.getItem(0).setEnabled(false);          // temp

	// Step 3.2.  Build "Chart" menu.
	String[] chartItems = new String[] { "Add bar chart", "Add pie chart",
					     "Add multiple bar charts",
					     "Add multiple pie charts" };
	String[] chartCmds = new String[] { ADD_BAR, ADD_PIE,
					    ADD_MULTIPLE_BARS,
					    ADD_MULTIPLE_PIES };
	menu = buildMenu("Chart", 'c', chartItems,
			 new char[] { 'b', 'p', 'm', 'u' },
			 chartCmds, this, bar);
	menu.getItem(0).setIcon(icons[0]);
	menu.getItem(1).setIcon(icons[1]);
	menu.insertSeparator(2);

	// Step 3.3.  Build "Help" menu.
	menu = buildMenu("Help", 'h',
			 new String[] { "Courseware Help System" },
			 new char[] { 'c' }, new String[] { HELP_COURSEWARE },
			 helpListener, bar);
	JMenuItem item = new JMenuItem("About", 'a');
	item.setActionCommand(HELP_ABOUT);
	item.addActionListener(this);
	menu.add(item);

	// Step 4.  Return menu bar.
	return bar;
    }

    /** Helper method for buildMenuBar(). */
    protected static JMenu buildMenu(String s,
				     char mnemonic,
				     String[] items,
				     char[] mnemonics,
				     String[] cmds,
				     ActionListener listener,
				     JMenuBar bar) {

	JMenu menu = new JMenu(s);
	menu.setMnemonic(mnemonic);
	for (int i=0; i<items.length; i++) {
	    JMenuItem item = new JMenuItem(items[i], mnemonics[i]);
	    item.setActionCommand(cmds[i]);
	    item.addActionListener(listener);
	    menu.add(item);
	}
	bar.add(menu);
	return menu;
    }




    //
    // Handling action events
    //

    public void actionPerformed(ActionEvent e) {
	String cmd = e.getActionCommand();

	if (cmd == SUBMIT) {
	    ContingencyTableModel model = tabulator.getDataOut();

	    // Need to clone the model without copying its listeners.  The
	    // reason is that the listeners (i.e., the charts) don't
	    // serialize and so building a Solution from the original model
	    // would prevent the Solution from serializing.
	    ContingencyTableModel clone =
		new ContingencyTableModel(model.getIndependents());
	    Vector tableData = clone.getDataVector();
	    int colIndex = model.getFrequencyColumnIndex();
	    for (int i = 0; i < model.getRowCount(); i++) {
		Vector rowData = (Vector)tableData.get(i);
		rowData.set(colIndex, model.getValueAt(i, colIndex));
	    }
	    clone.updateEstimates();

	    String exerciseID = getParameter("exercise_id");
	    Solution solution = new SetBuilderSolution(clone);
	    SetBuilderGrade grade =
		(SetBuilderGrade)submitSolution(exerciseID, solution);
	    JOptionPane.showInternalMessageDialog(desktopPane,
		grade.toString(), "Grade", JOptionPane.INFORMATION_MESSAGE);
	} else if (cmd == EXIT) {
	    return;	// temp
	} else if (cmd == HELP_ABOUT) {
	    String msg = "Set Builder Exercise\n" +
		"Copyright (c) 1999 by Willie Wheeler.  All rights reserved.";
	    JOptionPane.showInternalMessageDialog(desktopPane, msg, "About",
		JOptionPane.INFORMATION_MESSAGE);
	} else {	// Add one or more charts...
	    addChart(cmd);
	}
    }

    protected void addChart(String cmd) {

	// Ask the user to choose a distribution to chart.
	ContingencyTableModel model = tabulator.getDataOut();
	int type = (cmd == ADD_PIE || cmd == ADD_BAR ?
		    DistributionChooser.CONDITIONING_STATE :
		    DistributionChooser.CONDITIONING_VARIABLES);
	DistributionChooser chooser = new DistributionChooser(model, type);
	int option = JOptionPane.showInternalOptionDialog
	    (desktopPane, chooser, "Distribution Chooser",
	     JOptionPane.OK_CANCEL_OPTION, JOptionPane.QUESTION_MESSAGE,
	     null, null, null);
	int[] indeps = chooser.getSelectedIndependents();
	int dep = chooser.getSelectedDependent();
	int[][] condStates = chooser.getSelectedConditioningStates();

	// Make sure the user hasn't cancelled.  The user can cancel in
	// either of two ways: (1) by pressing the 'Cancel' button
	// explicitly, or (2) by selecting none of the independents and
	// pressing 'OK'.
	if (option == JOptionPane.CANCEL_OPTION || indeps.length == 0) {
	    return;
	}

	// Build the required chart(s).
	Vector charts = new Vector();
	Vector frameTitles = new Vector();
	for (int i = 0; i < condStates.length; i++) {
	    if (cmd == ADD_BAR || cmd == ADD_MULTIPLE_BARS) {
		charts.add(new BarChart(model, indeps, dep, condStates[i]));
		frameTitles.add("Bar Chart");
	    } else if (cmd == ADD_PIE || cmd == ADD_MULTIPLE_PIES) {
		charts.add(new PieChart(model, indeps, dep, condStates[i]));
		frameTitles.add("Pie Chart");
	    }
	}

	// Wrap and frame the chart(s).
	for (int i = 0; i < charts.size(); i++) {
	    Chart chart = (Chart)charts.get(i);
	    String frameTitle = (String)frameTitles.get(i);
	    ChartWrapper chartWrapper = new ChartWrapper(chart);
	    JInternalFrame chartFrame =
		new JInternalFrame(frameTitle, true, true, true, true);
	    chartFrame.getContentPane().add(chartWrapper);
	    chartFrame.setBounds(buildChartFrameBounds());
	    desktopPane.add(chartFrame);
	    desktopPane.moveToFront(chartFrame);
	}
    }

    /** Helper method for addChart().  Updates chartFrameX and chartFrameY
     *  as a side effect. */
    private Rectangle buildChartFrameBounds() {
	Rectangle bounds = new Rectangle(chartFrameX, chartFrameY, 200, 200);
	chartFrameY += 20;
	if (chartFrameY > CHART_FRAME_Y_MAX) {
	    chartFrameY = CHART_FRAME_Y_MIN;
	    chartFrameX += 20;
	    if (chartFrameX > CHART_FRAME_X_MAX) {
		chartFrameX = CHART_FRAME_X_MIN;
	    }
	}
	return bounds;
    }


    public String getExerciseServletClassID() {
	return "stats.exercises.SetBuilderExerciseServlet";
    }
}