package envoy.client.ui;

import java.awt.*;
import java.awt.TrayIcon.MessageType;

import javafx.application.Platform;
import javafx.stage.Stage;

import envoy.client.util.IconUtil;
import envoy.data.Message;

import dev.kske.eventbus.*;
import dev.kske.eventbus.Event;

/**
 * @author Kai S. K. Engelbart
 * @since Envoy Client v0.2-alpha
 */
public final class StatusTrayIcon implements EventListener {

	/**
	 * The {@link TrayIcon} provided by the System Tray API for controlling the
	 * system tray. This includes displaying the icon, but also creating
	 * notifications when new messages are received.
	 */
	private final TrayIcon trayIcon;

	/**
	 * A received {@link Message} is only displayed as a system tray notification if
	 * this variable is set to {@code true}.
	 */
	private boolean displayMessages;

	/**
	 * @return {@code true} if the status tray icon is supported on this platform
	 * @since Envoy Client v0.2-beta
	 */
	public static boolean isSupported() { return SystemTray.isSupported(); }

	/**
	 * Creates a {@link StatusTrayIcon} with the Envoy logo, a tool tip and a pop-up
	 * menu.
	 *
	 * @param stage the stage whose focus determines if message
	 *              notifications are displayed
	 * @since Envoy Client v0.2-beta
	 */
	public StatusTrayIcon(Stage stage) {
		trayIcon = new TrayIcon(IconUtil.loadAWTCompatible("/icons/envoy_logo.png"), "Envoy");
		trayIcon.setImageAutoSize(true);
		trayIcon.setToolTip("You are notified if you have unread messages.");

		final PopupMenu popup = new PopupMenu();

		final MenuItem exitMenuItem = new MenuItem("Exit");
		exitMenuItem.addActionListener(evt -> { Platform.exit(); System.exit(0); });
		popup.add(exitMenuItem);

		trayIcon.setPopupMenu(popup);

		// Only display messages if the stage is not focused
		stage.focusedProperty().addListener((ov, onHidden, onShown) -> displayMessages = !ov.getValue());

		// Show the window if the user clicks on the icon
		trayIcon.addActionListener(evt -> Platform.runLater(() -> { stage.setIconified(false); stage.toFront(); stage.requestFocus(); }));

		// Start processing message events
		EventBus.getInstance().registerListener(this);
	}

	/**
	 * Makes the icon appear in the system tray.
	 *
	 * @since Envoy Client v0.2-alpha
	 */
	public void show() {
		try {
			SystemTray.getSystemTray().add(trayIcon);
		} catch (final AWTException e) {}
	}

	/**
	 * Removes the icon from the system tray.
	 *
	 * @since Envoy Client v0.2-beta
	 */
	public void hide() { SystemTray.getSystemTray().remove(trayIcon); }

	@Event
	private void onMessage(Message message) {
		if (displayMessages) trayIcon.displayMessage(
				message.hasAttachment() ? "New " + message.getAttachment().getType().toString().toLowerCase() + " message received" : "New message received",
				message.getText(),
				MessageType.INFO);
	}
}