package com.ts3client.ui;

import com.ts3client.ui.tray.AwtTray;
import com.ts3client.ui.tray.TrayBackend;
import com.ts3client.ui.tray.X11Tray;

import javax.swing.JMenuItem;
import javax.swing.JPopupMenu;
import javax.swing.JWindow;
import javax.swing.SwingUtilities;
import javax.swing.event.PopupMenuEvent;
import javax.swing.event.PopupMenuListener;
import java.awt.Frame;
import java.awt.Image;
import java.awt.MenuItem;
import java.awt.PopupMenu;
import java.util.function.IntFunction;

/**
 * The system tray icon. It shows the local client's state on the active server —
 * the same badge the tree draws next to a nickname, so it turns green while
 * speaking and into the muted microphone or speaker when muted — and brings the
 * window back to the front when clicked.
 *
 * <p>The icon is docked by {@link X11Tray} where the panel can show a transparent
 * one, and by {@link AwtTray} everywhere else. On a desktop with no tray at all
 * nothing is installed and every call here is a no-op.
 */
final class TrayController {

    private final MainFrame frame;
    private final Runnable onQuit;

    private final TrayBackend tray;

    /** What is on screen now, so repeated updates don't touch the tray. */
    private SelfState state;
    private String tooltip = "";

    TrayController(MainFrame frame, Runnable onQuit) {
        this.frame = frame;
        this.onQuit = onQuit;
        this.tray = install();
    }

    /** What happened when the icon was installed, for the diagnostics in the chat log. */
    String status() {
        return tray == null
                ? "System tray: no icon could be installed (run with -Dts3j.tray.debug=true for why)."
                : "System tray: " + tray.description() + ".";
    }

    /** @return the backend that took the icon, or {@code null} when none could */
    private TrayBackend install() {
        TrayBackend.Listener listener = new TrayBackend.Listener() {
            @Override
            public void activated() {
                SwingUtilities.invokeLater(TrayController.this::show);
            }

            @Override
            public void menuRequested(int x, int y) {
                SwingUtilities.invokeLater(() -> showMenu(x, y));
            }
        };
        // -Dts3j.tray=awt|x11 pins the backend; by default the transparent one is
        // tried first and AWT's picks up whatever it leaves.
        String choice = System.getProperty("ts3j.tray", "auto");
        IntFunction<Image> initial = size -> SelfState.DISCONNECTED.icon(size).getImage();
        TrayBackend backend = choice.equals("awt") ? null : X11Tray.create(listener, initial);
        if (backend == null && !choice.equals("x11")) {
            backend = AwtTray.create(listener, buildAwtMenu(), initial);
        }
        return backend;
    }

    /** Shows the state of the given server, named by {@code serverName} in the tooltip. */
    void update(SelfState newState, String serverName) {
        if (tray == null) return;
        String newTooltip = "TS3J — " + (serverName == null || serverName.isBlank()
                ? newState.label()
                : serverName + ": " + newState.label());
        if (newState == state && newTooltip.equals(tooltip)) return;
        state = newState;
        tooltip = newTooltip;
        tray.setIcon(size -> newState.icon(size).getImage());
        tray.setTooltip(newTooltip);
    }

    /** Redraws after the icon pack changed. */
    void refreshIcon() {
        if (tray == null || state == null) return;
        SelfState current = state;
        tray.setIcon(size -> current.icon(size).getImage());
    }

    void dispose() {
        if (tray != null) tray.dispose();
    }

    // ---- menus ----

    /** The menu for AWT's icon, which shows one of its own. */
    private PopupMenu buildAwtMenu() {
        PopupMenu menu = new PopupMenu();
        MenuItem showItem = new MenuItem("Show TS3J");
        showItem.addActionListener(e -> SwingUtilities.invokeLater(this::show));
        MenuItem quitItem = new MenuItem("Quit");
        quitItem.addActionListener(e -> SwingUtilities.invokeLater(onQuit));
        menu.add(showItem);
        menu.addSeparator();
        menu.add(quitItem);
        return menu;
    }

    /**
     * The same menu for backends that have none — a Swing popup needs a component to
     * hang off, so it is given an empty window at the pointer.
     */
    private void showMenu(int x, int y) {
        JWindow anchor = new JWindow(frame);
        anchor.setLocation(x, y);
        anchor.setSize(1, 1);
        anchor.setVisible(true);

        JPopupMenu menu = new JPopupMenu();
        JMenuItem showItem = new JMenuItem("Show TS3J", Icons.app());
        showItem.addActionListener(e -> show());
        JMenuItem quitItem = new JMenuItem("Quit", Icons.of("QUIT"));
        quitItem.addActionListener(e -> onQuit.run());
        menu.add(showItem);
        menu.addSeparator();
        menu.add(quitItem);
        menu.addPopupMenuListener(new PopupMenuListener() {
            @Override
            public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
            }

            @Override
            public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
                anchor.dispose();
            }

            @Override
            public void popupMenuCanceled(PopupMenuEvent e) {
                anchor.dispose();
            }
        });
        menu.show(anchor, 0, 0);
    }

    /** Brings the window back from the taskbar or an iconified state. */
    private void show() {
        frame.setVisible(true);
        frame.setExtendedState(frame.getExtendedState() & ~Frame.ICONIFIED);
        frame.toFront();
        frame.requestFocus();
    }
}