using Godot;
using System;

// The in-VR menu content: plain Godot Controls, rendered by MenuScreen into its SubViewport.
// Built in code (no .tscn) so the spike can instantiate it without XR. Actions are C# events;
// WorldPanel wires them to the game. Sized for a 960x640 viewport on a 0.36x0.24 m panel
// (~2.7 px/mm): 26 px body text ≈ 1.2° at 45 cm, 64 px buttons ≈ 24 mm touch targets.
public partial class MainMenu : PanelContainer
{
    public const string CalibrationGroup = "calibration";

    private const int FontSize = 26;
    private const int ButtonHeight = 64;
    private const int MaxLogLines = 40;

    public event Action ReturnToSpawnRequested;
    public event Action ResetPropsRequested;
    public event Action PingRequested;
    public event Action CloseRequested;
    public event Action Clicked;
    public event Action<bool> SpectatorToggled;
    public event Action<bool> SmoothTurnToggled;
    public event Action<float> StrengthChanged;

    public TabContainer Tabs { get; private set; }
    public Button ReturnToSpawnButton { get; private set; }
    public Button RecalibrateButton { get; private set; }
    public Button ResetPropsButton { get; private set; }
    public Button PingButton { get; private set; }
    public Button CloseButton { get; private set; }
    public Button HeaderCloseButton { get; private set; }
    public HSlider ClickVolumeSlider { get; private set; }
    public HSlider StrengthSlider { get; private set; }
    public Button SpectatorButton { get; private set; }
    public Button TurnModeButton { get; private set; }
    public ScrollContainer LogScroll { get; private set; }

    private Label _fpsLabel;
    private Label _calibrationStatus;
    private VBoxContainer _logLines;
    private double _refreshTimer;

    public MainMenu()
    {
        Theme = BuildTheme();
        BuildLayout();
    }

    public override void _Ready() => RefreshCalibration();

    public override void _Process(double delta)
    {
        _refreshTimer -= delta;
        if (_refreshTimer > 0)
            return;
        _refreshTimer = 0.25;
        _fpsLabel.Text = $"{Engine.GetFramesPerSecond():0} fps";
        RefreshCalibration();
    }

    // Contract with the body-calibration work: a node in group "calibration" exposing
    // Recalibrate(). Absent → button disabled. We never create that node here.
    public Node FindCalibration()
    {
        if (!IsInsideTree())
            return null;
        Node node = GetTree().GetFirstNodeInGroup(CalibrationGroup);
        return node != null && node.HasMethod("Recalibrate") ? node : null;
    }

    public void RefreshCalibration()
    {
        bool available = FindCalibration() != null;
        RecalibrateButton.Disabled = !available;
        _calibrationStatus.Text = available ? "" : "Not available";
    }

    public void Log(string line)
    {
        _logLines.AddChild(new Label { Text = line, AutowrapMode = TextServer.AutowrapMode.WordSmart });
        while (_logLines.GetChildCount() > MaxLogLines)
        {
            Node oldest = _logLines.GetChild(0);
            _logLines.RemoveChild(oldest);
            oldest.QueueFree();
        }
    }

    private void BuildLayout()
    {
        VBoxContainer root = new();
        root.AddThemeConstantOverride("separation", 10);
        AddChild(root);

        HBoxContainer header = new();
        header.AddThemeConstantOverride("separation", 16);
        root.AddChild(header);
        Label title = new() { Text = "VR Messs", SizeFlagsHorizontal = SizeFlags.ExpandFill, VerticalAlignment = VerticalAlignment.Center };
        title.AddThemeFontSizeOverride("font_size", 30);
        header.AddChild(title);
        _fpsLabel = new Label { Text = "-- fps", VerticalAlignment = VerticalAlignment.Center };
        _fpsLabel.AddThemeColorOverride("font_color", new Color(0.6f, 0.68f, 0.8f));
        header.AddChild(_fpsLabel);
        HeaderCloseButton = MakeButton("Close", () => CloseRequested?.Invoke());
        HeaderCloseButton.CustomMinimumSize = new Vector2(120, 52);
        header.AddChild(HeaderCloseButton);

        Tabs = new TabContainer { SizeFlagsVertical = SizeFlags.ExpandFill, TabFocusMode = FocusModeEnum.None };
        Tabs.TabChanged += _ => Clicked?.Invoke();
        root.AddChild(Tabs);

        // Player
        VBoxContainer player = MakePage("Player");
        ReturnToSpawnButton = MakeButton("Return to spawn", () => ReturnToSpawnRequested?.Invoke());
        player.AddChild(ReturnToSpawnButton);
        HBoxContainer calibRow = new();
        calibRow.AddThemeConstantOverride("separation", 16);
        RecalibrateButton = MakeButton("Recalibrate body", Recalibrate);
        RecalibrateButton.SizeFlagsHorizontal = SizeFlags.ExpandFill;
        calibRow.AddChild(RecalibrateButton);
        _calibrationStatus = new Label { VerticalAlignment = VerticalAlignment.Center };
        _calibrationStatus.AddThemeColorOverride("font_color", new Color(0.6f, 0.6f, 0.65f));
        calibRow.AddChild(_calibrationStatus);
        player.AddChild(calibRow);

        // Nimso's single strength value: every muscle and the hand guides scale with it.
        HBoxContainer strengthRow = new();
        strengthRow.AddThemeConstantOverride("separation", 20);
        Label strengthLabel = new() { Text = "Strength 1.00×", VerticalAlignment = VerticalAlignment.Center, CustomMinimumSize = new Vector2(220, 0) };
        strengthRow.AddChild(strengthLabel);
        StrengthSlider = new HSlider
        {
            MinValue = 0.25,
            MaxValue = 3,
            Step = 0.05,
            Value = 1,
            SizeFlagsHorizontal = SizeFlags.ExpandFill,
            SizeFlagsVertical = SizeFlags.ShrinkCenter,
            CustomMinimumSize = new Vector2(0, 48),
            FocusMode = FocusModeEnum.None,
        };
        StrengthSlider.ValueChanged += v =>
        {
            strengthLabel.Text = $"Strength {v:0.00}×";
            StrengthChanged?.Invoke((float)v);
        };
        strengthRow.AddChild(StrengthSlider);
        player.AddChild(strengthRow);

        HBoxContainer modeRow = new();
        modeRow.AddThemeConstantOverride("separation", 16);
        TurnModeButton = MakeToggle("Turning: snap", "Turning: smooth", on => SmoothTurnToggled?.Invoke(on));
        modeRow.AddChild(TurnModeButton);
        // Spectator: no body; fly around by grabbing the air (the old drag movement).
        SpectatorButton = MakeToggle("Spectator: off", "Spectator: on (grab-fly)", on => SpectatorToggled?.Invoke(on));
        modeRow.AddChild(SpectatorButton);
        player.AddChild(modeRow);
        Tabs.AddChild(player);

        // World
        VBoxContainer world = MakePage("World");
        ResetPropsButton = MakeButton("Reset props", () => ResetPropsRequested?.Invoke());
        world.AddChild(ResetPropsButton);
        PingButton = MakeButton("Ping sound", () => PingRequested?.Invoke());
        world.AddChild(PingButton);
        Tabs.AddChild(world);

        // System
        VBoxContainer system = MakePage("System");
        HBoxContainer volumeRow = new();
        volumeRow.AddThemeConstantOverride("separation", 20);
        volumeRow.AddChild(new Label { Text = "Click volume", VerticalAlignment = VerticalAlignment.Center, CustomMinimumSize = new Vector2(200, 0) });
        ClickVolumeSlider = new HSlider
        {
            MinValue = 0,
            MaxValue = 100,
            Step = 1,
            Value = 70,
            SizeFlagsHorizontal = SizeFlags.ExpandFill,
            SizeFlagsVertical = SizeFlags.ShrinkCenter,
            CustomMinimumSize = new Vector2(0, 48),
            FocusMode = FocusModeEnum.None,
        };
        volumeRow.AddChild(ClickVolumeSlider);
        system.AddChild(volumeRow);
        CloseButton = MakeButton("Close menu", () => CloseRequested?.Invoke());
        system.AddChild(CloseButton);
        Label logTitle = new() { Text = "Log (swipe or thumbstick to scroll)" };
        logTitle.AddThemeColorOverride("font_color", new Color(0.6f, 0.68f, 0.8f));
        system.AddChild(logTitle);
        LogScroll = new ScrollContainer
        {
            SizeFlagsVertical = SizeFlags.ExpandFill,
            HorizontalScrollMode = ScrollContainer.ScrollMode.Disabled,
        };
        _logLines = new VBoxContainer { SizeFlagsHorizontal = SizeFlags.ExpandFill };
        _logLines.AddThemeConstantOverride("separation", 2);
        LogScroll.AddChild(_logLines);
        system.AddChild(LogScroll);
        Tabs.AddChild(system);
    }

    private void Recalibrate()
    {
        Node calibration = FindCalibration();
        if (calibration == null)
        {
            RefreshCalibration();
            return;
        }
        GD.Print("MainMenu: Recalibrate body → calibration.Recalibrate()");
        calibration.Call("Recalibrate");
    }

    private static VBoxContainer MakePage(string title)
    {
        VBoxContainer page = new() { Name = title };
        page.AddThemeConstantOverride("separation", 14);
        return page;
    }

    private Button MakeToggle(string offText, string onText, Action<bool> changed)
    {
        Button button = new()
        {
            Text = offText,
            ToggleMode = true,
            CustomMinimumSize = new Vector2(0, ButtonHeight),
            SizeFlagsHorizontal = SizeFlags.ExpandFill,
            FocusMode = FocusModeEnum.None,
        };
        button.Toggled += on =>
        {
            button.Text = on ? onText : offText;
            Clicked?.Invoke();
            Callable.From(() => changed(on)).CallDeferred();
        };
        return button;
    }

    private Button MakeButton(string text, Action action)
    {
        Button button = new()
        {
            Text = text,
            CustomMinimumSize = new Vector2(0, ButtonHeight),
            FocusMode = FocusModeEnum.None,
        };
        button.Pressed += () =>
        {
            Clicked?.Invoke();
            // Deferred: actions may hide/move the panel; never do that from inside the
            // input event MenuScreen is injecting.
            Callable.From(action).CallDeferred();
        };
        return button;
    }

    private static StyleBoxFlat Box(Color bg, int radius, float marginX, float marginY, Color? border = null, int borderWidth = 0)
    {
        StyleBoxFlat box = new() { BgColor = bg };
        box.SetCornerRadiusAll(radius);
        box.ContentMarginLeft = marginX;
        box.ContentMarginRight = marginX;
        box.ContentMarginTop = marginY;
        box.ContentMarginBottom = marginY;
        if (border is Color c)
        {
            box.BorderColor = c;
            box.SetBorderWidthAll(borderWidth);
        }
        return box;
    }

    private static Theme BuildTheme()
    {
        Color accent = new(0.35f, 0.6f, 0.95f);
        Theme theme = new() { DefaultFontSize = FontSize };

        theme.SetStylebox("panel", "PanelContainer", Box(new Color(0.07f, 0.08f, 0.11f), 0, 18, 14));

        theme.SetStylebox("normal", "Button", Box(new Color(0.17f, 0.2f, 0.27f), 10, 20, 8));
        theme.SetStylebox("hover", "Button", Box(new Color(0.24f, 0.31f, 0.44f), 10, 20, 8, accent, 3));
        theme.SetStylebox("pressed", "Button", Box(new Color(0.33f, 0.5f, 0.78f), 10, 20, 8, new Color(0.7f, 0.85f, 1f), 3));
        theme.SetStylebox("hover_pressed", "Button", Box(new Color(0.33f, 0.5f, 0.78f), 10, 20, 8, new Color(0.7f, 0.85f, 1f), 3));
        theme.SetStylebox("disabled", "Button", Box(new Color(0.11f, 0.12f, 0.15f), 10, 20, 8));
        theme.SetStylebox("focus", "Button", new StyleBoxEmpty());
        theme.SetColor("font_color", "Button", new Color(0.92f, 0.94f, 0.98f));
        theme.SetColor("font_hover_color", "Button", Colors.White);
        theme.SetColor("font_pressed_color", "Button", Colors.White);
        theme.SetColor("font_disabled_color", "Button", new Color(0.45f, 0.47f, 0.52f));

        theme.SetStylebox("panel", "TabContainer", Box(new Color(0.1f, 0.12f, 0.16f), 10, 18, 16));
        StyleBoxFlat tabSelected = Box(new Color(0.1f, 0.12f, 0.16f), 0, 28, 12);
        tabSelected.CornerRadiusTopLeft = 10;
        tabSelected.CornerRadiusTopRight = 10;
        tabSelected.BorderColor = accent;
        tabSelected.BorderWidthTop = 4;
        theme.SetStylebox("tab_selected", "TabContainer", tabSelected);
        StyleBoxFlat tabUnselected = Box(new Color(0.13f, 0.15f, 0.2f), 0, 28, 12);
        tabUnselected.CornerRadiusTopLeft = 10;
        tabUnselected.CornerRadiusTopRight = 10;
        theme.SetStylebox("tab_unselected", "TabContainer", tabUnselected);
        StyleBoxFlat tabHovered = Box(new Color(0.2f, 0.26f, 0.37f), 0, 28, 12);
        tabHovered.CornerRadiusTopLeft = 10;
        tabHovered.CornerRadiusTopRight = 10;
        theme.SetStylebox("tab_hovered", "TabContainer", tabHovered);
        theme.SetStylebox("tab_focus", "TabContainer", new StyleBoxEmpty());
        theme.SetConstant("tab_separation", "TabContainer", 6);
        theme.SetFontSize("font_size", "TabContainer", FontSize);

        // Slider: thick track, big round grabber (default icons are ~16 px — too small in VR).
        StyleBoxFlat track = Box(new Color(0.17f, 0.2f, 0.27f), 6, 0, 6);
        theme.SetStylebox("slider", "HSlider", track);
        theme.SetStylebox("grabber_area", "HSlider", Box(accent, 6, 0, 6));
        theme.SetStylebox("grabber_area_highlight", "HSlider", Box(accent.Lightened(0.2f), 6, 0, 6));
        theme.SetIcon("grabber", "HSlider", Circle(36, new Color(0.9f, 0.94f, 1f)));
        theme.SetIcon("grabber_highlight", "HSlider", Circle(36, Colors.White));
        theme.SetIcon("grabber_disabled", "HSlider", Circle(36, new Color(0.4f, 0.4f, 0.45f)));

        // Wide scrollbar so it is touchable.
        theme.SetStylebox("scroll", "VScrollBar", Box(new Color(0.13f, 0.15f, 0.2f), 8, 14, 0));
        theme.SetStylebox("grabber", "VScrollBar", Box(new Color(0.3f, 0.36f, 0.48f), 8, 14, 0));
        theme.SetStylebox("grabber_highlight", "VScrollBar", Box(new Color(0.4f, 0.5f, 0.68f), 8, 14, 0));
        theme.SetStylebox("grabber_pressed", "VScrollBar", Box(accent, 8, 14, 0));

        theme.SetColor("font_color", "Label", new Color(0.88f, 0.9f, 0.95f));
        return theme;
    }

    private static ImageTexture Circle(int size, Color color)
    {
        Image image = Image.CreateEmpty(size, size, false, Image.Format.Rgba8);
        float r = size * 0.5f;
        for (int y = 0; y < size; y++)
        {
            for (int x = 0; x < size; x++)
            {
                float d = new Vector2(x + 0.5f - r, y + 0.5f - r).Length();
                float a = Mathf.Clamp(r - d, 0f, 1f); // 1 px anti-aliased edge
                image.SetPixel(x, y, new Color(color, a));
            }
        }
        return ImageTexture.CreateFromImage(image);
    }
}