package com.onaro.sanscreen.client.login;

import java.awt.Point;
import java.io.IOException;

import javax.security.auth.callback.Callback;
import javax.security.auth.callback.UnsupportedCallbackException;
import javax.swing.Icon;
import javax.swing.JButton;
import javax.swing.JFrame;

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.
 */
public class SplashScreen extends JFrame implements LoginHandlerDialog {

    /**
     * Initializes a splash screen and displays it in the center of the screen.
     */
    public SplashScreen() {
        /*
         * The following statement is needed just for Mac OS X transparency. It doesn't
         * affect Linux or Windows.
         *
         * Note: This statement stopped having the desired effect at some point due to
         * an Oracle bug (JDK-8013450). Oracle says the bug will be fixed in Java 9.
         * Meanwhile, a gray box is displayed behind the splash screen on Mac OS.
         * Not too bad, so will leave it as is and hope Oracle gets it working again.
         */
        getRootPane().putClientProperty ("Window.alpha", new Float(0.0F)); //$NON-NLS-1$
        
        // Create frame. Only seen by user in OS task bar and task switcher.
        setTitle (SANscreenClientPlugin.getDefault().getBranding().getProductName());
        setIconImage (SANscreenClientPlugin.getDefault().getBranding().getWindowIcon());
        setResizable (false);
        setUndecorated (true);
        setDefaultCloseOperation (EXIT_ON_CLOSE);
        
        // Create window that user sees.
        window = new SplashWindow (this);
        
        // Must call setVisible to make frame visible in OS task list, though we won't see frame.
        setVisible (true);
        
        // Repaint needed to force display of initial image, which is now the only image with a shadow.
        window.repaint();
    }
    
    @Override
    public CallbackHandlerPane getCallbackHandlerPane() {
        return getLoginDialog().getCallbackHandlerPane();
    }

    @Override
    public JButton getOkButton() {
        return getLoginDialog().getOkButton();
    }

    @Override
    public JButton getCancelButton() {
        return getLoginDialog().getCancelButton();
    }

    @Override
    public void handle(Callback[] callbacks) throws IOException, UnsupportedCallbackException {
        getLoginDialog().handle (callbacks);
    }
    
    @Override
    public void setLoginEnabled(boolean enabled) {
        getLoginDialog().setLoginEnabled (enabled);
    }

    @Override
    public void requestLogin() {
        // Make sure splash window is visible. Made invisible after login failure.
        window.showLoginBackground();
        window.setVisible (true);
        window.toFront();
        getLoginDialog().requestLogin();
    }

    @Override
    public void failLogin() {
        // Hide splash window while showing About box that's displayed when login fails.
        hideMessage();
        window.setVisible (false);
        getLoginDialog().failLogin();
        // LoginHandler calls requestLogin() after failure.
    }
    
    @Override
    public void endLogin() {
        hideMessage();
        if (loginDialog != null) {
            loginDialog.endLogin();
        }
        window.toFront();
    }
    
    /**
     * Show a message indicating that login is in process
     */
    public void showMessageLoggingIn() {
        window.showMessageLoggingIn();
    }

    /**
     * Show a message indicating that initialization is in process
     */
    public void showMessageInitializing() {
        window.showMessageInitializing();
    }
    
    /**
     * 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) {
        window.setMessage (icon);
    }
    
    /**
     * 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) {
        window.setStatus (text);
    }
    
    /**
     * Hide any message that is displayed
     */
    public void hideMessage() {
        window.hideMessage();
    }
    
    /**
     * Hides and disposes the splash window and its owner frame.
     */
    public void done() {
        setVisible (false);
        window.done();
        dispose();
    }
    

    private LoginHandlerDialog getLoginDialog() {
		if (loginDialog == null) {
		    // Align login dialog to splash window.
		    Point location = window.getLocationOnScreen();
		    location.x += LOGIN_DIALOG_X_OFFSET;
		    location.y += LOGIN_DIALOG_Y_OFFSET;
		    
		    // Create login dialog box.
			CallbackHandlerDialog dialog = new CallbackHandlerDialog(this);
			dialog.setBounds (location.x, location.y, LOGIN_DIALOG_WIDTH, LOGIN_DIALOG_HEIGHT);
			loginDialog = dialog;
		}
		return loginDialog;
    }
    
    private static final long serialVersionUID = 1L;
    
    private static final int LOGIN_DIALOG_X_OFFSET = 205;
    private static final int LOGIN_DIALOG_Y_OFFSET = 80;
    private static final int LOGIN_DIALOG_WIDTH = 260;
    private static final int LOGIN_DIALOG_HEIGHT = 160;
    
    private final SplashWindow window;
    private LoginHandlerDialog loginDialog = null;
}