package edu.princeton.toy;

import java.awt.*;
import java.io.*;

import javax.swing.*;

/**
 * TMain is the class which contains the main function for the X-TOY application.  It also parses
 * the version file.
 *
 * @author btsang
 * @version 7.1
 */

public class TMain
{
    private static final TMain INSTANCE = new TMain();

    private Image frameIcon;
    private String version;
    private String buildDate;

    /**
     * Constructs a new TMain.
     */
    private TMain()
    {
        version = "(Error)";
        buildDate = "(Error)";
    }

    /**
     * Parses the version file, launches a splash window until all the example, image, and parameter
     * managers are ready.  Then launches an untitled frame.
     */
    public static void main(String arguments[])
    {
        System.out.println("Visual X-TOY");

        // Load the version
        try
        {
            StringBuffer buffer = new StringBuffer();
            Reader reader = TResourceLoader.getReader("version");
            int character = reader.read();

            while (character != '\n' && character != -1)
            {
                buffer.append((char)character);
                character = reader.read();
            }

            if (character == '\n')
            {
                INSTANCE.version = buffer.toString();
                character = reader.read();
                buffer.delete(0, buffer.length());

                while (character != '\n' && character != -1)
                {
                    buffer.append((char)character);
                    character = reader.read();
                }

                if (character == '\n')
                {
                    INSTANCE.buildDate = buffer.toString();
                    character = reader.read();
                }
            }
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }

        System.out.println("Version:       " + INSTANCE.version);
        System.out.println("Build Date:    " + INSTANCE.buildDate);
        System.out.println("OS Name:       " + System.getProperty("os.name"));
        System.out.println("User Home:     " + System.getProperty("user.home"));
        System.out.println("Class Version: " + System.getProperty("java.class.version"));
        System.out.println("JVM Version:   " + System.getProperty("java.version"));

        // Test to make sure that this version wasn't compiled with Java >= 1.4 when this JVM
        // is < 1.4.
        try
        {
            // This is an interesting test because it uses the fact that in Java >= 1.4, appending
            // a StringBuffer to a StringBuffer is handled by a special method which treats the
            // appendee as a StringBuffer.  Whereas previous versions of Java did not have this
            // method and would treat the StringBuffer as just any old Object, inefficiently
            // calling the toString() method of it.

            StringBuffer buffer1 = new StringBuffer("foo");
            StringBuffer buffer2 = new StringBuffer("bar");

            // This would cause a NoSuchMethodException if a >= 1.4 compiler tried to use the
            // special method which a < 1.4 JVM would not have.
            buffer1.append(buffer2);
        }
        catch (NoSuchMethodError e)
        {
            e.printStackTrace();

            JOptionPane.showMessageDialog(
                null,
                "You are executing a version of Visual X-TOY that requires Java 1.4 or better,\n" +
                "but your version of java is " + System.getProperty("java.version") + ".\n" +
                "Please upgrade your JVM or use the Java 1.3 compatible version of Visual X-TOY.",
                "JVM Error",
                JOptionPane.ERROR_MESSAGE
                );

            System.exit(-1);
        }


        try
        {
            // Show the spash screen
            TImageManager.prepare(TImageManager.STARTUP_UNSCALED_IMAGE_GROUP);
            TSplashWindow splashWindow = new TSplashWindow();
            splashWindow.setVisible(true);
            splashWindow.requestFocus();
            splashWindow.toFront();

            // Wait for the resources to load
            while (!TExampleManager.isReady() || !TConfigurationManager.isReady())
            {
                Thread.sleep(500);
            }

            TImageManager.prepare(TImageManager.REGULAR_UNSCALED_IMAGE_GROUP);

            {   // Have the JFileChooser do some warm ups (if this is not done, the first showing
                // of the dialog will make it look like the button that launched it froze the
                // entire program for about 20 seconds)
                JFileChooser chooser = new JFileChooser();

                File currentDirectory = TOptionsFrame.getCurrentDirectory();
                if (currentDirectory != null)
                    chooser.setCurrentDirectory(currentDirectory);

                chooser.rescanCurrentDirectory();
            }

            // Figure out which icon to show
            String osName = System.getProperty("os.name").toLowerCase();
            if (osName.indexOf("windows") != -1)
            {
                INSTANCE.frameIcon = TImageManager.getImage(
                    TImageManager.REGULAR_UNSCALED_IMAGE_GROUP,
                    TImageManager.REGULAR_UNSCALED_FRAME_ICON_WINDOWS
                    );
            }
            else {
                INSTANCE.frameIcon = TImageManager.getImage(
                    TImageManager.REGULAR_UNSCALED_IMAGE_GROUP,
                    TImageManager.REGULAR_UNSCALED_FRAME_ICON_OTHER_OS
                    );
            }

            // Create a frame and show it
            TFrame.createInitialFrame();

            // Get rid of the splash screen
            splashWindow.setVisible(false);
            splashWindow.dispose();
        }
        catch (Exception e)
        {
            e.printStackTrace();
            System.exit(0);
        }
    }

    /**
     * Returns the version, as parsed from the version file.
     *
     * @return The version of this application.
     */
    public static String getVersion()
    {
        return INSTANCE.version;
    }

    /**
     * Returns the build date, as parsed from the version file.
     *
     * @return The build date of this application.
     */
    public static String getBuildDate()
    {
        return INSTANCE.buildDate;
    }

    /**
     * Returns the frame icon that should be used in this OS.
     *
     * @return The image for the frame icon that should be used in this OS.
     */
    public static Image getFrameIcon()
    {
        return INSTANCE.frameIcon;
    }
}