package com.onaro.sanscreen.client.login;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.Icon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JLayeredPane;
import javax.swing.JPanel;
import javax.swing.JWindow;
import javax.swing.Timer;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import com.onaro.commons.swing.OnaroSwingUtilities;
import com.onaro.sanscreen.client.Resources;
import com.onaro.sanscreen.client.SANscreenClientPlugin;

/**
 * Displays a border less window with an image and a progress indicator. Used
 * to pass the time while the application initializes.
 */
/*package*/ class SplashWindow extends JWindow {

    /**
     * Initializes a splash screen and displays it in the center of the screen.
     */
    public SplashWindow (JFrame owner) {
        super (owner);
        
        /*
         * Make splash window non-opaque if possible, so there isn't a white rectangle under the image.
         * Use new Java 7 methods to do this.
         */
        try {
            setBackground (OnaroSwingUtilities.TRANSPARENT);
        } catch (Exception e) {
            // Not that big a deal if window has to be opaque. Just a visual artifact.
            logger.info ("Can't make splash screen non-opaque. " + e.getMessage()); //$NON-NLS-1$
        }

        // Create back panel and make it the content pane;
        Icon splashIcon = SANscreenClientPlugin.getDefault().getBranding().getSplashScreenIcon();
        backPanel = new BackPanel (splashIcon);
        setSize(backPanel.getSize());
        setContentPane (backPanel);

        // Put on top of other windows, in center of screen.
        setVisible (true);
        setLocationRelativeTo (null);
        toFront();
    }
    
    /**
     * Show a message indicating that login is in process
     */
    public void showMessageLoggingIn() {
        // Make sure copyright or login prompt isn't visible.
        showProgressBackground();

        // Display image for message.
        JLabel label = getMessageLabel();
        startMessageAnimation (
                Resources.INSTANCE.getLoggingIn0(),
                Resources.INSTANCE.getLoggingIn1(),
                Resources.INSTANCE.getLoggingIn2(),
                Resources.INSTANCE.getLoggingIn3()
                );
        label.setVisible (true);
    }

    /**
     * Show a message indicating that initialization is in process
     */
    public void showMessageInitializing() {
        // Make sure copyright or login prompt isn't visible.
        showProgressBackground();
        
        // Display image for message.
        JLabel label = getMessageLabel();
        startMessageAnimation (
                Resources.INSTANCE.getInitializing0(),
                Resources.INSTANCE.getInitializing1(),
                Resources.INSTANCE.getInitializing2(),
                Resources.INSTANCE.getInitializing3()
                );
        label.setVisible (true);
    }
    
    /**
     * If a message is currently being displayed, change the message icon
     * @param icon message icon or {@code null} to display no icon
     * @see #showMessage
     */
    public void setMessage (Icon icon) {
        if (icon == null) {
            stopMessageAnimation();
        }
        if (messageLabel != null && messageLabel.isVisible()) {
            messageLabel.setIcon (icon);
            messageLabel.repaint();
        }
    }
    
    /**
     * If a message is currently being displayed, change the status text
     * @param text status text or {@code null} to display no text
     * @see #showMessage
     */
    public void setStatus (String text) {
        if (messageLabel != null && messageLabel.isVisible()) {
            getStatusLabel().setText (text);
            getStatusLabel().repaint();
        }
    }
    
    /**
     * Hide any message that is displayed
     */
    public void hideMessage() {
        stopMessageAnimation();
        if (messageLabel != null) {
            messageLabel.setVisible (false);
            messageLabel.repaint();
        }
        if (statusLabel != null) {
            statusLabel.setVisible (false);
            statusLabel.repaint();
        }
    }
    /**
     * Hides and disposes the splash window and its owner frame.
     */
    public void done() {
        stopMessageAnimation();
        setVisible (false);
        dispose();
    }
    
    private JLabel getMessageLabel() {
        if (messageLabel == null) {
            // Create message label.
            messageLabel = new JLabel();
            messageLabel.setBackground (Color.white);
            
			// Add label to dialog.
			messageLabel.setBounds (MESSAGE_LABEL_X, MESSAGE_LABEL_Y, MESSAGE_LABEL_WIDTH, MESSAGE_LABEL_HEIGHT);
			messageLabel.setOpaque (true);
			JLayeredPane layer = getLayeredPane();
			layer.add (messageLabel, JLayeredPane.POPUP_LAYER);
        }
        return messageLabel;
    }
    
    private JLabel getStatusLabel() {
        if (statusLabel == null) {
            // Create status label.
            statusLabel = new JLabel();
            statusLabel.setForeground (Color.gray);
            statusLabel.setBackground (Color.white);
            
			// Add label to dialog.
			statusLabel.setBounds (STATUS_LABEL_X, STATUS_LABEL_Y, STATUS_LABEL_WIDTH, STATUS_LABEL_HEIGHT);
			statusLabel.setOpaque (true);
			JLayeredPane layer = getLayeredPane();
			layer.add (statusLabel, JLayeredPane.POPUP_LAYER);
        }
        return statusLabel;
    }

    private void showProgressBackground() {
        backPanel.setIcon (Resources.INSTANCE.getSplashNoCopyright());
    }

    public void showLoginBackground() {
        backPanel.setIcon (Resources.INSTANCE.getSplashLogin());
    }
    
    /*
     * The resource bundle mechanism doesn't handle required animated GIFs
     * correctly (because it relies on MediaTracker to find out when loading is done)
     * so we load the icons individually and animate them ourself.
     * 
     */
    private void startMessageAnimation (final Icon... icons) {
        // Stop previous animation, if any.
        stopMessageAnimation();
        
        // Start by showing last icon.
        final int nIcons = icons.length;
        setMessage (icons[nIcons - 1]);
        
        // Display first icon after initial timer delay.
        iIcon = 0;
        
        // Create Swing timer to show each icon for about half a second.
        timer = new Timer (500, new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                setMessage (icons[iIcon]);
                if (++iIcon == nIcons) {
                    iIcon = 0;
                }
            }
        });
        timer.start();
    }
    
    private void stopMessageAnimation() {
        if (timer != null) {
            timer.stop();
            timer = null;
            if (messageLabel != null) {
                messageLabel.setIcon (null);
                messageLabel.repaint();
            }
        }
    }
    
    private class BackPanel extends JPanel {
        private static final long serialVersionUID = 1L;
        private final Dimension size;
        private Icon icon;
        
        public BackPanel (Icon icon) {
            this.size = new Dimension (icon.getIconWidth(), icon.getIconHeight());
            this.icon = icon;
            this.setBackground (OnaroSwingUtilities.TRANSPARENT);
        }
        
        public void setIcon (Icon newIcon) {
            // May often be called with same icon. Don't repaint unnecessarily.
            if (this.icon != newIcon) {
                this.icon = newIcon;
                // Note this will darken any translucent image areas, such as shadows in the image.
                // Work-around to this was to only draw a shadow in the initial image.
                repaint();
            }
        }
        
        @Override
        public Dimension getSize() {
            return size;
        }
        
        @Override
        protected void paintComponent (Graphics graphics) {
            icon.paintIcon (this, graphics, 0, 0);
        }
    }
    
    private static final long serialVersionUID = 1L;
    private static final Logger logger = LogManager.getLogger (SplashWindow.class);
    
    private static final int MESSAGE_LABEL_X = 205;
    private static final int MESSAGE_LABEL_Y = 180;
    private static final int MESSAGE_LABEL_WIDTH = 300;
    private static final int MESSAGE_LABEL_HEIGHT = 40;
    
    private static final int STATUS_LABEL_X = 205;
    private static final int STATUS_LABEL_Y = 215;
    private static final int STATUS_LABEL_WIDTH = 300;
    private static final int STATUS_LABEL_HEIGHT = 30;
    
    private BackPanel backPanel = null;
	private JLabel messageLabel = null;
	private JLabel statusLabel = null;
	private Timer timer = null;
	private int iIcon = 0;
}