/*
 * DavMail POP/IMAP/SMTP/CalDav/LDAP Exchange Gateway
 * Copyright (C) 2009  Mickael Guessant
 *
 * This program 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 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package davmail.ui.tray;

import davmail.BundleMessage;
import davmail.DavGateway;
import davmail.Settings;
import davmail.ui.AboutFrame;
import davmail.ui.SettingsFrame;
import davmail.util.IOUtil;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.DeviceData;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.internal.gtk.OS;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.ToolTip;
import org.eclipse.swt.widgets.Tray;
import org.eclipse.swt.widgets.TrayItem;

import javax.swing.*;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;

/**
 * Tray icon handler based on SWT
 */
public class SwtGatewayTray implements DavGatewayTrayInterface {
    private static final Logger LOGGER = Logger.getLogger(SwtGatewayTray.class);

    private static final Object LOCK = new Object();

    protected SwtGatewayTray() {
    }

    SettingsFrame settingsFrame;
    AboutFrame aboutFrame;

    private static TrayItem trayItem;
    private static ArrayList<java.awt.Image> frameIcons;

    private static Image image;
    private static Image image2;
    private static Image inactiveImage;
    private static Display display;
    private static Shell shell;
    private boolean isActive = true;
    private boolean isReady;
    private Error error;
    private boolean firstMessage = true;

    /**
     * Return AWT Image icon for frame title.
     *
     * @return frame icon
     */
    @Override
    public java.util.List<java.awt.Image> getFrameIcons() {
        return frameIcons;
    }

    /**
     * Switch tray icon between active and standby icon.
     */
    public void switchIcon() {
        isActive = true;
        display.syncExec(() -> {
            Image currentImage = trayItem.getImage();
            if (currentImage != null && currentImage.equals(image)) {
                trayItem.setImage(image2);
            } else {
                trayItem.setImage(image);
            }
        });

    }

    /**
     * Set tray icon to inactive (network down)
     */
    public void resetIcon() {
        display.syncExec(() -> trayItem.setImage(image));
    }

    /**
     * Set tray icon to inactive (network down)
     */
    public void inactiveIcon() {
        isActive = false;
        display.syncExec(() -> trayItem.setImage(inactiveImage));
    }

    /**
     * Check if current tray status is inactive (network down).
     *
     * @return true if inactive
     */
    public boolean isActive() {
        return isActive;
    }

    /**
     * Log and display balloon message according to log level.
     *
     * @param message text message
     * @param level   log level
     */
    public void displayMessage(final String message, final Level level) {
        if (trayItem != null) {
            display.asyncExec(() -> {
                int messageType = 0;
                if (level.equals(Level.INFO)) {
                    messageType = SWT.ICON_INFORMATION;
                } else if (level.equals(Level.WARN)) {
                    messageType = SWT.ICON_WARNING;
                } else if (level.equals(Level.ERROR)) {
                    messageType = SWT.ICON_ERROR;
                }
                if (messageType != 0) {
                    final ToolTip toolTip = new ToolTip(shell, SWT.BALLOON | messageType);
                    toolTip.setText(BundleMessage.format("UI_DAVMAIL_GATEWAY"));
                    toolTip.setMessage(message);
                    trayItem.setToolTip(toolTip);
                    // Wait for tray init 1 second on first message
                    if (firstMessage) {
                        firstMessage = false;
                        try {
                            Thread.sleep(1000);
                        } catch (InterruptedException e) {
                            Thread.currentThread().interrupt();
                        }
                    }
                    toolTip.setVisible(true);
                }
                trayItem.setToolTipText(BundleMessage.format("UI_DAVMAIL_GATEWAY") + '\n' + message);
            });
        }
    }

    /**
     * Load image with current class loader.
     *
     * @param fileName image resource file name
     * @return image
     */
    public static Image loadSwtImage(String fileName) {
        Image result = null;
        try {
            ClassLoader classloader = DavGatewayTray.class.getClassLoader();
            URL imageUrl = classloader.getResource(fileName);
            if (imageUrl == null) {
                throw new IOException(fileName);
            }
            byte[] imageContent = IOUtil.readFully(imageUrl.openStream());
            Image tempImage = new Image(display, new ByteArrayInputStream(imageContent));
            Image backgroundImage = new Image(null, 24, 24);
            ImageData imageData = backgroundImage.getImageData();
            imageData.transparentPixel = imageData.getPixel(0, 0);
            backgroundImage.dispose();
            result = new Image(null, imageData);

            GC gc = new GC(result);
            gc.drawImage(tempImage, 4, 4);
            tempImage.dispose();

        } catch (IOException e) {
            DavGatewayTray.warn(new BundleMessage("LOG_UNABLE_TO_LOAD_IMAGE"), e);
        }
        return result;
    }

    /**
     * Create tray icon and register frame listeners.
     */
    public void init() {
        boolean isGTK3;
        // SWT 4.9 and later
        try {
            Class gtk = Class.forName("org.eclipse.swt.internal.gtk.GTK");
            isGTK3 = (Boolean) gtk.getDeclaredField("GTK3").get(null);
            LOGGER.debug("org.eclipse.swt.internal.gtk.GTK.GTK3="+isGTK3);
            if (isGTK3) {
                LOGGER.warn("GTK 3 not supported, please set SWT_GTK3=0");
            }
        } catch (Throwable e) {
            // ignore
        }
        try {
            Class gdk = Class.forName("org.eclipse.swt.internal.gtk.GDK");
            //noinspection unchecked
            gdk.getDeclaredMethod("gdk_error_trap_push").invoke(null);
            LOGGER.debug("Called org.eclipse.swt.internal.gtk.GDK.gdk_error_trap_push");
        } catch (Throwable e) {
            // ignore
        }

        try {
            //noinspection JavaReflectionMemberAccess
            OS.class.getDeclaredMethod("gdk_error_trap_push").invoke(null);
            LOGGER.debug("Called org.eclipse.swt.internal.gtk.OS.gdk_error_trap_push");
        } catch (Exception e) {
            // ignore
        }
        try {
            // workaround for bug when SWT and AWT both try to access Gtk
            UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName());
        } catch (Exception e) {
            DavGatewayTray.warn(new BundleMessage("LOG_UNABLE_TO_SET_LOOK_AND_FEEL"));
        }

        new Thread("SWT") {
            @Override
            public void run() {
                try {
                    DeviceData data = new DeviceData();
                    data.debug = true;
                    display = new Display(data);
                    shell = new Shell(display);

                    final Tray tray = display.getSystemTray();
                    if (tray != null) {

                        trayItem = new TrayItem(tray, SWT.NONE);
                        trayItem.setToolTipText(BundleMessage.format("UI_DAVMAIL_GATEWAY"));

                        frameIcons = new ArrayList<>();
                        frameIcons.add(DavGatewayTray.loadImage(AwtGatewayTray.TRAY128_PNG));
                        frameIcons.add(DavGatewayTray.loadImage(AwtGatewayTray.TRAY_PNG));

                        image = loadSwtImage(AwtGatewayTray.TRAY_PNG);
                        image2 = loadSwtImage(AwtGatewayTray.TRAY_ACTIVE_PNG);
                        inactiveImage = loadSwtImage(AwtGatewayTray.TRAY_INACTIVE_PNG);

                        trayItem.setImage(image);
                        trayItem.addDisposeListener(e -> {
                            if (image != null && !image.isDisposed()) {
                                image.dispose();
                            }
                            if (image2 != null && !image2.isDisposed()) {
                                image2.dispose();
                            }
                            if (inactiveImage != null && !inactiveImage.isDisposed()) {
                                inactiveImage.dispose();
                            }
                        });

                        // create a popup menu
                        final Menu popup = new Menu(shell, SWT.POP_UP);
                        trayItem.addListener(SWT.MenuDetect, event -> display.asyncExec(
                                () -> popup.setVisible(true)));

                        MenuItem aboutItem = new MenuItem(popup, SWT.PUSH);
                        aboutItem.setText(BundleMessage.format("UI_ABOUT"));
                        aboutItem.addListener(SWT.Selection, event -> SwingUtilities.invokeLater(
                                () -> {
                                    if (aboutFrame == null) {
                                        aboutFrame = new AboutFrame();
                                    }
                                    aboutFrame.update();
                                    aboutFrame.setVisible(true);
                                    aboutFrame.toFront();
                                    aboutFrame.requestFocus();
                                }));

                        // create menu item for the default action
                        trayItem.addListener(SWT.DefaultSelection, event -> SwingUtilities.invokeLater(
                                () -> openSettingsFrame()));

                        MenuItem defaultItem = new MenuItem(popup, SWT.PUSH);
                        defaultItem.setText(BundleMessage.format("UI_SETTINGS"));
                        defaultItem.addListener(SWT.Selection, event -> SwingUtilities.invokeLater(
                                () -> openSettingsFrame()));

                        MenuItem logItem = new MenuItem(popup, SWT.PUSH);
                        logItem.setText(BundleMessage.format("UI_SHOW_LOGS"));
                        logItem.addListener(SWT.Selection, event -> SwingUtilities.invokeLater(DavGatewayTray::showLogs));

                        MenuItem exitItem = new MenuItem(popup, SWT.PUSH);
                        exitItem.setText(BundleMessage.format("UI_EXIT"));
                        exitItem.addListener(SWT.Selection, event -> DavGateway.stop());

                        // display settings frame on first start
                        if (Settings.isFirstStart()) {
                            SwingUtilities.invokeLater(() -> {
                                // create frame on first call
                                if (settingsFrame == null) {
                                    settingsFrame = new SettingsFrame();
                                }
                                settingsFrame.setVisible(true);
                                settingsFrame.toFront();
                                settingsFrame.requestFocus();
                            });

                        }

                        synchronized (LOCK) {
                            // ready
                            isReady = true;
                            LOCK.notifyAll();
                        }

                        while (!shell.isDisposed()) {
                            if (!display.readAndDispatch()) {
                                display.sleep();
                            }
                        }
                    }
                    // dispose AWT frames
                    if (settingsFrame != null) {
                        settingsFrame.dispose();
                    }
                    if (aboutFrame != null) {
                        aboutFrame.dispose();
                    }
                } catch (Exception exc) {
                    DavGatewayTray.error(exc);
                } catch (Error exc) {
                    error = exc;
                    throw exc;
                }
                // make sure we do exit
                System.exit(0);
            }
        }.start();
        while (true) {
            // wait for SWT init
            try {
                synchronized (LOCK) {
                    if (error != null) {
                        throw error;
                    }
                    if (isReady) {
                        break;
                    }
                    LOCK.wait(1000);
                }
            } catch (InterruptedException e) {
                DavGatewayTray.error(new BundleMessage("LOG_ERROR_WAITING_FOR_SWT_INIT"), e);
                Thread.currentThread().interrupt();
            }
        }
    }

    private void openSettingsFrame() {
        // create frame on first call
        if (settingsFrame == null) {
            settingsFrame = new SettingsFrame();
        }
        settingsFrame.reload();
        settingsFrame.setVisible(true);
        settingsFrame.toFront();
        settingsFrame.requestFocus();
    }

    public void dispose() {
        shell.dispose();
    }

}
