/*
 * Jalview - A Sequence Alignment Editor and Viewer ($$Version-Rel$$)
 * Copyright (C) $$Year-Rel$$ The Jalview Authors
 * 
 * This file is part of Jalview.
 * 
 * Jalview 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.
 *  
 * Jalview 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 Jalview.  If not, see <http://www.gnu.org/licenses/>.
 * The Jalview Authors are detailed in the 'AUTHORS' file.
 */
package jalview.gui;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.JInternalFrame;
import javax.swing.JLabel;
import javax.swing.JLayeredPane;
import javax.swing.JPanel;
import javax.swing.JTextPane;
import javax.swing.event.HyperlinkEvent;
import javax.swing.event.HyperlinkListener;

import jalview.util.ChannelProperties;
import jalview.util.Platform;

import javajs.async.SwingJSUtils.StateHelper;
import javajs.async.SwingJSUtils.StateMachine;

/**
 * DOCUMENT ME!
 * 
 * @author $author$
 * @version $Revision$
 */
@SuppressWarnings("serial")
public class SplashScreen extends JPanel
        implements HyperlinkListener, StateMachine
{
  
  private static final int STATE_INIT = 0;

  private static final int STATE_LOOP = 1;

  private static final int STATE_DONE = 2;
  private static final int SHOW_FOR_SECS = 5;

  private static final int FONT_SIZE = (Platform.isJS() ? 14 : 11);

  private boolean visible = true;

  private JPanel iconimg = new JPanel(new BorderLayout());

  // could change fg, bg, font later to use ChannelProperties (these are not
  // actually being used!)
  private static Color bg = Color.WHITE;

  private static Color fg = Color.BLACK;

  private static Font font = new Font("SansSerif", Font.PLAIN, FONT_SIZE);

  private JPanel imgPanel = new JPanel(new BorderLayout());

  /*
   * as JTextPane in Java, JLabel in javascript
   */
  private Component splashText;

  private JInternalFrame iframe;

  private Image image, logo;

  private boolean transientDialog = false;

  private long oldTextLength = -1;

  private StateHelper helper;
  public static int logoSize = 32;

  /*
   * allow click in the initial splash screen to dismiss it
   * immediately (not if opened from About menu)
   */
  private MouseAdapter closer = new MouseAdapter()
  {
    @Override
    public void mousePressed(MouseEvent evt)
    {
      if (transientDialog)
      {
        try
        {
          closeSplash();
        } catch (Exception ex)
        {
        }
      }
    }
  };

  /**
   * Constructor that displays the splash screen
   * 
   * @param isStartup
   *          if true the panel removes itself on click or after a few seconds;
   *          if false it stays up until closed by the user (from Help..About menu)
   */
  public SplashScreen(boolean isStartup)
  {
    this.transientDialog = isStartup;
    // we must get the image in JavaScript BEFORE starting the helper,
    // as it will take a 1 ms clock tick to obtain width and height information.
    image = ChannelProperties.getImage("banner");
    logo = ChannelProperties.getImage("logo.48");
    font = new Font("SansSerif", Font.PLAIN, FONT_SIZE);
    helper = new StateHelper(this);
    helper.next(STATE_INIT);
  }

  protected void initSplashScreenWindow()
  {
    addMouseListener(closer);
    waitForImages();
    setLayout(new BorderLayout());
    iframe = new JInternalFrame();
    iframe.setFrameIcon(null);
    iframe.setClosable(true);
    iframe.setContentPane(this);
    iframe.setLayer(JLayeredPane.PALETTE_LAYER);  
    SplashImage splashimg = new SplashImage(image);
    imgPanel.add(splashimg, BorderLayout.CENTER);
    add(imgPanel, BorderLayout.NORTH);
    Desktop.getDesktopPane().add(iframe);
    refreshText();
  }

  /**
   * Both Java and JavaScript have to wait for images, but this method will
   * accomplish nothing for JavaScript. We have already taken care of image
   * loading with our state loop in JavaScript.
   * 
   */
  private void waitForImages()
  {
    if (Platform.isJS())
      return;
    MediaTracker mt = new MediaTracker(this);
    mt.addImage(image, 0);
    mt.addImage(logo, 1);
    do
    {
      try
      {
        mt.waitForAll();
      } catch (InterruptedException x)
      {
      }
      if (mt.isErrorAny())
      {
        System.err.println("Error when loading images!");
        break;
      }
    } while (!mt.checkAll());
    if (logo != null)
    {
      Desktop.getInstance().setIconImage(logo);
    }

    this.setBackground(bg);
    this.setForeground(fg);
    this.setFont(font);
  }

  /**
   * update text in author text panel reflecting current version information
   */
  protected boolean refreshText()
  {
    String newtext = Desktop.getInstance().getAboutMessage();
    // System.err.println("Text found: \n"+newtext+"\nEnd of newtext.");
    if (oldTextLength == newtext.length())
    {
      return false;
    }
  
    iframe.setVisible(false);
    oldTextLength = newtext.length();
    if (Platform.isJS()) // BH 2019
    {
      /*
       * SwingJS doesn't have HTMLEditorKit, required for a JTextPane
       * to display formatted html, so we use a simple alternative
       */
      String text = "<html><br><img src=\""
              + ChannelProperties.getImageURL("banner") + "\"/>" + newtext
              + "<br></html>";
      JLabel ta = new JLabel(text);
      ta.setOpaque(true);
      ta.setBackground(Color.white);
      splashText = ta;
    }
    else
    /**
     * Java only
     *
     * @j2sIgnore
     */
    {
      JTextPane jtp = new JTextPane();
      jtp.setEditable(false);
      jtp.setBackground(bg);
      jtp.setForeground(fg);
      jtp.setFont(font);
      jtp.setContentType("text/html");
      jtp.setText("<html>" + newtext + "</html>");
      jtp.addHyperlinkListener(this);
      splashText = jtp;
    }
    splashText.addMouseListener(closer);

    splashText.setVisible(true);
    splashText.setSize(new Dimension(750,
            375 + logoSize + (Platform.isJS() ? 40 : 0)));
    splashText.setBackground(bg);
    splashText.setForeground(fg);
    splashText.setFont(font);
    add(splashText, BorderLayout.CENTER);
    revalidate();
    int width = Math.max(splashText.getWidth(), iconimg.getWidth());
    int height = splashText.getHeight() + iconimg.getHeight();
    iframe.setBounds((iframe.getParent().getWidth() - width) / 2,
            (iframe.getParent().getHeight() - height) / 2,
            width,height);
    iframe.validate();
    iframe.setVisible(true);
    return true;
  }

  protected void closeSplash()
  {
    try
    {

      iframe.setClosed(true);
    } catch (Exception ex)
    {
    }
  }

  /**
   * A simple state machine with just three states: init, loop, and done. Ideal
   * for a simple while/sleep loop that works in Java and JavaScript
   * identically.
   * 
   */
  @Override
  public boolean stateLoop()
  {
    while (true)
    {
      switch (helper.getState())
      {
      case STATE_INIT:
        initSplashScreenWindow();
        helper.setState(STATE_LOOP);
        continue;
      case STATE_LOOP:
        if (!isVisible())
        {
          helper.setState(STATE_DONE);
          continue;
        }
        if (refreshText())
        {
          iframe.repaint();
        }
        if (transientDialog)
          helper.delayedState(SHOW_FOR_SECS * 1000, STATE_DONE);
        return true;
      default:
      case STATE_DONE:
        setVisible(false);
        closeSplash();
        Desktop.getInstance().startDialogQueue();
        return true;
      }
    }

  }

  private class SplashImage extends JPanel
  {
    Image image;

    public SplashImage(Image todisplay)
    {
      image = todisplay;
      if (image != null)
      {
        setPreferredSize(new Dimension(image.getWidth(this) + 8,
                image.getHeight(this)));
      }
    }

    @Override
    public Dimension getPreferredSize()
    {
      return new Dimension(image.getWidth(this) + 8, image.getHeight(this));
    }

    @Override
    public void paintComponent(Graphics g)
    {
      g.setColor(bg);
      g.fillRect(0, 0, getWidth(), getHeight());
      g.setColor(fg);
      g.setFont(new Font(font.getFontName(), Font.BOLD, FONT_SIZE + 6));

      if (image != null)
      {
        g.drawImage(image, (getWidth() - image.getWidth(this)) / 2,
                (getHeight() - image.getHeight(this)) / 2, this);
      }
    }
  }

  @Override
  public void hyperlinkUpdate(HyperlinkEvent e)
  {
    Desktop.hyperlinkUpdate(e);

  }
}