package envoy.client.ui;

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

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

import envoy.client.event.OwnStatusChange;
import envoy.client.helper.ShutdownHelper;
import envoy.client.util.*;
import envoy.data.Message;
import envoy.data.User.UserStatus;

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 var popup = new PopupMenu();

		// Adding the exit menu item
		final var exitMenuItem = new MenuItem("Exit");
		exitMenuItem.addActionListener(evt -> ShutdownHelper.exit(true));
		popup.add(exitMenuItem);

		// Adding the logout menu item
		final var logoutMenuItem = new MenuItem("Logout");
		logoutMenuItem.addActionListener(evt -> { hide(); Platform.runLater(UserUtil::logout); });
		popup.add(logoutMenuItem);

		// Adding the status change items
		final var statusSubMenu = new Menu("Change status");
		for (final var status : UserStatus.values()) {
			final var statusMenuItem = new MenuItem(status.toString().toLowerCase());
			statusMenuItem.addActionListener(evt -> Platform.runLater(() -> UserUtil.changeStatus(status)));
			statusSubMenu.add(statusMenuItem);
		}
		popup.add(statusSubMenu);

		trayIcon.setPopupMenu(popup);

		// Only display messages if the stage is not focused and the current user status
		// is not BUSY (if BUSY, displayMessages will be false)
		stage.focusedProperty().addListener((ov, wasFocused, isFocused) -> displayMessages = !displayMessages && wasFocused ? false : !isFocused);

		// 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 onOwnStatusChange(OwnStatusChange statusChange) { displayMessages = !statusChange.get().equals(UserStatus.BUSY); }

	@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);
	}
}