using System.Numerics;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using Hexa.NET.ImGui;
using SDL3;

namespace SDL3_TestingSuite.SDL3;

/// <summary>
/// Implementation of SDL3 platform backend for ImGui.
/// https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_sdl3.h
/// </summary>
public unsafe static class ImGuiSDL3Platform
{
    public class PlatformData
    {
        public nint Window;
        public uint WindowID;
        public nint Renderer;
        public ulong Time;
        public nint ClipboardTextData;
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 48)]
        public byte[] BackendPlatformName = new byte[48];
        public bool UseVulkan;
        public bool WantUpdateMonitors;

        // IME Handling
        public nint ImeWindow;
        public ImGuiPlatformImeData ImeData;
        public bool ImeDirty;

        // Mouse Handling
        public uint MouseWindowID;
        public int MouseButtonsDown;
        public readonly nint[] MouseCursors = new nint[(int)ImGuiMouseCursor.Count];
        public nint MouseLastCursor;
        public int MouseLastLeaveFrame;
        public bool MouseCanUseGlobalState;
        public bool MouseCanReportHoveredViewport;
        public MouseCaptureMode MouseCaptureMode;

        // Gamepad Handling
        public readonly nint[] Gamepads = new nint[16];
        public int GamepadCount;
        public GamepadMode GamepadMode;
        public bool WantUpdateGamepadsList;

        public PlatformData()
        {
            MouseLastCursor = nint.Zero;

            for (int i = 0; i < MouseCursors.Length; i++)
                MouseCursors[i] = nint.Zero;

            for (int i = 0; i < Gamepads.Length; i++)
                Gamepads[i] = nint.Zero;
        }
    }

    public class ViewPortData
    {
        public nint Window;
        public nint Renderer;
        public nint ParentWindow;
        public uint WindowID; // Stored in ImGuiViewport.PlatformHandle. Use SDL.GetWindowFromID() to get SDL.Window* from Uint32 WindowID.
        public bool WindowOwned;
        public bool RendererOwned;
    }

    // ReSharper disable NotAccessedField.Local
    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate nint PlatformGetClipboardTextFn(nint ctx);
    private static readonly PlatformGetClipboardTextFn GetClipboardDelegate = GetClipboardText;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate void PlatformSetClipboardTextFn(nint ctx, nint text);
    private static readonly PlatformSetClipboardTextFn SetClipboardDelegate = SetClipboardText;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate void PlatformSetImeDataFn(nint ctx, nint userData, nint imeData);
    private static readonly PlatformSetImeDataFn SetImeDataDelegate = SetImeData;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate bool PlatformOpenInShellFn(nint ctx, nint url);
    private static readonly PlatformOpenInShellFn OpenInShellDelegate = OpenInShell;
    // ReSharper restore NotAccessedField.Local

    public static PlatformData Data => ImGui.GetCurrentContext().Handle != null ? ImGuiUserData<PlatformData>.Get(ImGui.GetIO().BackendPlatformUserData)! : null!;

    public static bool Init(nint window, nint renderer)
    {
        ImGuiIOPtr io = ImGui.GetIO();
        PlatformData data = new PlatformData
        {
            Window = window,
            Renderer = renderer,
            WindowID = SDL.GetWindowID(window)
        };

        io.BackendPlatformUserData = ImGuiUserData<PlatformData>.Store(data);
        io.BackendFlags |= ImGuiBackendFlags.HasMouseCursors;
        io.BackendFlags |= ImGuiBackendFlags.HasSetMousePos;

        data.MouseCanUseGlobalState = false;
        data.MouseCaptureMode = MouseCaptureMode.Disabled;

        string? backend = SDL.GetCurrentVideoDriver();
        string[] captureAndGlobalStateWhitelist = new string[] { "windows", "cocoa", "x11", "DIVE", "VMAN", "wayland" };
        foreach (var item in captureAndGlobalStateWhitelist)
        {
            if (item != backend) continue;
            data.MouseCanUseGlobalState = true;
            data.MouseCaptureMode = item == "x11" ? MouseCaptureMode.EnabledAfterDrag : MouseCaptureMode.Enabled;
        }
        if (data.MouseCanUseGlobalState)
        {
            io.BackendFlags |= ImGuiBackendFlags.PlatformHasViewports; // We can create multi-viewports on the Platform side (optional)
        }

#if __APPLE__
        data.MouseCanReportHoveredViewport = false;
#else
        data.MouseCanReportHoveredViewport = data.MouseCanUseGlobalState;
#endif

        ImGuiPlatformIOPtr platformIo = ImGui.GetPlatformIO();
        platformIo.PlatformGetClipboardTextFn = (void*)Marshal.GetFunctionPointerForDelegate(GetClipboardDelegate);
        platformIo.PlatformSetClipboardTextFn = (void*)Marshal.GetFunctionPointerForDelegate(SetClipboardDelegate);
        platformIo.PlatformSetImeDataFn = (void*)Marshal.GetFunctionPointerForDelegate(SetImeDataDelegate);
        platformIo.PlatformOpenInShellFn = (void*)Marshal.GetFunctionPointerForDelegate(OpenInShellDelegate);

        UpdateMonitors();

        data.GamepadMode = GamepadMode.AutoFirst;
        data.WantUpdateGamepadsList = true;

        data.MouseCursors[(int)ImGuiMouseCursor.Arrow] = SDL.CreateSystemCursor(SDL.SystemCursor.Default);
        data.MouseCursors[(int)ImGuiMouseCursor.TextInput] = SDL.CreateSystemCursor(SDL.SystemCursor.Text);
        data.MouseCursors[(int)ImGuiMouseCursor.ResizeAll] = SDL.CreateSystemCursor(SDL.SystemCursor.Move);
        data.MouseCursors[(int)ImGuiMouseCursor.ResizeNs] = SDL.CreateSystemCursor(SDL.SystemCursor.NSResize);
        data.MouseCursors[(int)ImGuiMouseCursor.ResizeEw] = SDL.CreateSystemCursor(SDL.SystemCursor.EWResize);
        data.MouseCursors[(int)ImGuiMouseCursor.ResizeNesw] = SDL.CreateSystemCursor(SDL.SystemCursor.NESWResize);
        data.MouseCursors[(int)ImGuiMouseCursor.ResizeNwse] = SDL.CreateSystemCursor(SDL.SystemCursor.NWSEResize);
        data.MouseCursors[(int)ImGuiMouseCursor.Hand] = SDL.CreateSystemCursor(SDL.SystemCursor.Pointer);
        data.MouseCursors[(int)ImGuiMouseCursor.Wait] = SDL.CreateSystemCursor(SDL.SystemCursor.Wait);
        data.MouseCursors[(int)ImGuiMouseCursor.Progress] = SDL.CreateSystemCursor(SDL.SystemCursor.Progress);
        data.MouseCursors[(int)ImGuiMouseCursor.NotAllowed] = SDL.CreateSystemCursor(SDL.SystemCursor.NotAllowed);

        SetupPlatformHandles(ImGui.GetMainViewport(), window);

        SDL.SetHint(SDL.Hints.MouseFocusClickthrough, "1");
        SDL.SetHint(SDL.Hints.MouseAutoCapture, "0");
        SDL.SetHint("SDL_BORDERLESS_WINDOWED_STYLE", "0");

        if ((io.BackendFlags & ImGuiBackendFlags.PlatformHasViewports) != 0)
            InitMultiViewportSupport(window);

        return true;
    }

    private static void GetWindowSizeAndFramebufferScale(nint window, out Vector2 out_size, out Vector2 out_framebuffer_scale)
    {
        SDL.GetWindowSize(window, out int w, out int h);
        if ((SDL.GetWindowFlags(window) & SDL.WindowFlags.Minimized) != 0)
            w = h = 0;

        SDL.GetWindowSizeInPixels(window, out int displayW, out int displayH);
        float fbScaleX = w > 0 ? displayW / (float)w : 1.0f;
        float fbScaleY = h > 0 ? displayH / (float)h : 1.0f;

        out_size = new Vector2(w, h);
        out_framebuffer_scale = new Vector2(fbScaleX, fbScaleY);
    }


    public static void NewFrame()
    {
        ImGuiIOPtr io = ImGui.GetIO();
        PlatformData data = Data;

        GetWindowSizeAndFramebufferScale(data.Window, out Vector2 size, out Vector2 framebufferScale);

        if (data.WantUpdateMonitors)
        {
            UpdateMonitors();
        }
        
        ulong frequency = SDL.GetPerformanceFrequency();
        ulong currentTime = SDL.GetPerformanceCounter();
        if (currentTime <= data.Time)
            currentTime = data.Time + 1;
        io.DeltaTime = data.Time > 0 ? (float)((currentTime - data.Time) / (double)frequency) : 1.0f / 60.0f;
        data.Time = currentTime;

        io.DisplaySize = size;
        io.DisplayFramebufferScale = framebufferScale;

        if (data.MouseLastLeaveFrame > 0 && data.MouseLastLeaveFrame >= ImGui.GetFrameCount() && data.MouseButtonsDown == 0)
        {
            data.MouseWindowID = 0;
            data.MouseLastLeaveFrame = 0;
            io.AddMousePosEvent(-float.MaxValue, -float.MaxValue);
        }

        if (data.MouseCanReportHoveredViewport && ImGui.GetDragDropPayload().Equals(nint.Zero))
        {
            io.BackendFlags |= ImGuiBackendFlags.HasMouseHoveredViewport;
        }
        else
        {
            io.BackendFlags &= ~ImGuiBackendFlags.HasMouseHoveredViewport;
        }

        UpdateMouseData(data);
        UpdateMouseCursor(data);
        UpdateIme(data);

        UpdateGamepads(data);
    }

    public static bool ProcessEvent(SDL.Event e)
    {
        ImGuiIOPtr io = ImGui.GetIO();
        PlatformData data = Data;

        switch ((SDL.EventType)e.Type)
        {
            case SDL.EventType.MouseMotion:
                if (GetViewportForWindowId(e.Motion.WindowID) == null)
                    return false;

                io.AddMouseSourceEvent(e.Motion.Which == SDL.TouchMouseID ? ImGuiMouseSource.TouchScreen : ImGuiMouseSource.Mouse);
                io.AddMousePosEvent(e.Motion.X, e.Motion.Y);
                return true;
            case SDL.EventType.MouseWheel:
                if (GetViewportForWindowId(e.Wheel.WindowID) == null)
                    return false;

                float wheelX = -e.Wheel.X;
                float wheelY = e.Wheel.Y;

                io.AddMouseSourceEvent(e.Wheel.Which == SDL.TouchMouseID ? ImGuiMouseSource.TouchScreen : ImGuiMouseSource.Mouse);
                io.AddMouseWheelEvent(wheelX, wheelY);
                return true;
            case SDL.EventType.MouseButtonDown:
            case SDL.EventType.MouseButtonUp:
                if (GetViewportForWindowId(e.Button.WindowID) == null)
                    return false;

                int mouseButton = e.Button.Button switch
                {
                    SDL.ButtonLeft   => 0,
                    SDL.ButtonRight  => 1,
                    SDL.ButtonMiddle => 2,
                    SDL.ButtonX1     => 3,
                    SDL.ButtonX2     => 4,
                    _                => -1
                };
                if (mouseButton == -1) break;

                io.AddMouseSourceEvent(e.Button.Which == SDL.TouchMouseID ? ImGuiMouseSource.TouchScreen : ImGuiMouseSource.Mouse);
                io.AddMouseButtonEvent(mouseButton, (SDL.EventType)e.Type == SDL.EventType.MouseButtonDown);
                data.MouseButtonsDown = (SDL.EventType)e.Type == SDL.EventType.MouseButtonDown ? data.MouseButtonsDown | 1 << mouseButton : data.MouseButtonsDown & ~(1 << mouseButton);
                return true;
            case SDL.EventType.TextInput:
                if (GetViewportForWindowId(e.Text.WindowID) == null)
                    return false;

                ImGui.GetIO().AddInputCharactersUTF8((byte*)e.Text.Text);
                return true;
            case SDL.EventType.KeyDown:
            case SDL.EventType.KeyUp:
                if (GetViewportForWindowId(e.Key.WindowID) == null)
                    return false;

                UpdateKeyModifiers(e.Key.Mod);
                ImGuiKey imguiKey = KeyEventToImGui(e.Key.Key, e.Key.Scancode);
                bool pressed = (SDL.EventType)e.Type == SDL.EventType.KeyDown;

                io.AddKeyEvent(imguiKey, pressed);
                io.SetKeyEventNativeData(imguiKey, (int)e.Key.Key, (int)e.Key.Scancode, (int)e.Key.Scancode);

                return true;
            case SDL.EventType.WindowMouseEnter:
                if (GetViewportForWindowId(e.Window.WindowID) == null)
                    return false;

                data.MouseWindowID = e.Window.WindowID;
                data.MouseLastLeaveFrame = 0;
                return true;
            case SDL.EventType.WindowMouseLeave:
                if (GetViewportForWindowId(e.Window.WindowID) == null)
                    return false;

                data.MouseLastLeaveFrame = ImGui.GetFrameCount() + 1;
                return true;
            case SDL.EventType.WindowFocusGained:
            case SDL.EventType.WindowFocusLost:
                if (GetViewportForWindowId(e.Window.WindowID) == null)
                    return false;

                io.AddFocusEvent((SDL.EventType)e.Type == SDL.EventType.WindowFocusGained);
                return true;
        }

        return false;
    }

    private static void UpdateMouseData(PlatformData data)
    {
        if (SDL.GetKeyboardFocus() == data.Window && ImGui.GetIO().WantSetMousePos)
            SDL.WarpMouseInWindow(data.Window, (int)ImGui.GetIO().MousePos.X, (int)ImGui.GetIO().MousePos.Y);
    }

    private static void UpdateMouseCursor(PlatformData data)
    {
        ImGuiIOPtr io = ImGui.GetIO();

        if ((io.ConfigFlags & ImGuiConfigFlags.NoMouseCursorChange) != 0)
            return;

        ImGuiMouseCursor cursor = ImGui.GetMouseCursor();

        if (io.MouseDrawCursor || cursor == ImGuiMouseCursor.None)
        {
            SDL.HideCursor();
            return;
        }

        nint expected = data.MouseCursors[(int)cursor];

        if (data.MouseLastCursor != expected)
        {
            SDL.SetCursor(expected);
            data.MouseLastCursor = expected;
        }

        SDL.ShowCursor();
    }

    private static void CloseGamepads()
    {
        PlatformData bd = Data;

        if (bd.GamepadMode != GamepadMode.Manual)
        {
            for (int i = 0; i < bd.GamepadCount; i++)
            {
                SDL.CloseGamepad(bd.Gamepads[i]);
                bd.Gamepads[i] = nint.Zero;
            }
        }

        bd.GamepadCount = 0;
    }

    private static void SetGamepadMode(GamepadMode mode, nint[] manual_gamepads_array, int manual_gamepads_count)
    {
        PlatformData bd = Data;

        CloseGamepads();

        if (mode == GamepadMode.Manual)
        {
            int count = manual_gamepads_count;

            if (count > bd.Gamepads.Length)
                count = bd.Gamepads.Length;

            for (int n = 0; n < count; n++)
                bd.Gamepads[n] = manual_gamepads_array[n];

            bd.GamepadCount = count;
        }
        else
        {
            bd.WantUpdateGamepadsList = true;
        }

        bd.GamepadMode = mode;
    }

    private static void UpdateGamepadButton(PlatformData bd, ImGuiIOPtr io, ImGuiKey key, SDL.GamepadButton button_no)
    {
        bool mergedValue = false;

        for (int i = 0; i < bd.GamepadCount; i++)
        {
            nint gamepad = bd.Gamepads[i];
            mergedValue |= SDL.GetGamepadButton(gamepad, button_no);
        }

        io.AddKeyEvent(key, mergedValue);
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    private static float Saturate(float v)
    {
        return v < 0.0f ? 0.0f : v > 1.0f ? 1.0f : v;
    }
    private static void UpdateGamepadAnalog(PlatformData bd, ImGuiIOPtr io, ImGuiKey key, SDL.GamepadAxis axis_no, float v0, float v1)
    {
        float mergedValue = 0.0f;

        for (int i = 0; i < bd.GamepadCount; i++)
        {
            nint gamepad = bd.Gamepads[i];

            float raw = SDL.GetGamepadAxis(gamepad, axis_no);
            float vn = Saturate((raw - v0) / (v1 - v0));

            if (mergedValue < vn)
                mergedValue = vn;
        }

        io.AddKeyAnalogEvent(key, mergedValue > 0.1f, mergedValue);
    }

    private static void UpdateGamepads(PlatformData data)
    {
        ImGuiIOPtr io = ImGui.GetIO();

        if (data.WantUpdateGamepadsList && data.GamepadMode != GamepadMode.Manual)
        {
            CloseGamepads();

            uint[] sdlGamepads = SDL.GetGamepads(out int count);

            for (int n = 0; n < count; n++)
            {
                if (data.GamepadCount >= data.Gamepads.Length)
                    break;

                data.Gamepads[data.GamepadCount++] = SDL.OpenGamepad(sdlGamepads[n]);

                if (data.GamepadMode == GamepadMode.AutoFirst)
                    break;
            }

            data.WantUpdateGamepadsList = false;
        }

        io.BackendFlags &= ~ImGuiBackendFlags.HasGamepad;

        if (data.GamepadCount == 0)
            return;

        io.BackendFlags |= ImGuiBackendFlags.HasGamepad;

        const int thumbDeadZone = 8000;

        UpdateGamepadButton(data, io, ImGuiKey.GamepadStart, SDL.GamepadButton.Start);
        UpdateGamepadButton(data, io, ImGuiKey.GamepadBack, SDL.GamepadButton.Back);
        UpdateGamepadButton(data, io, ImGuiKey.GamepadFaceLeft, SDL.GamepadButton.West);
        UpdateGamepadButton(data, io, ImGuiKey.GamepadFaceRight, SDL.GamepadButton.East);
        UpdateGamepadButton(data, io, ImGuiKey.GamepadFaceUp, SDL.GamepadButton.North);
        UpdateGamepadButton(data, io, ImGuiKey.GamepadFaceDown, SDL.GamepadButton.South);
        UpdateGamepadButton(data, io, ImGuiKey.GamepadDpadLeft, SDL.GamepadButton.DPadLeft);
        UpdateGamepadButton(data, io, ImGuiKey.GamepadDpadRight, SDL.GamepadButton.DPadRight);
        UpdateGamepadButton(data, io, ImGuiKey.GamepadDpadUp, SDL.GamepadButton.DPadUp);
        UpdateGamepadButton(data, io, ImGuiKey.GamepadDpadDown, SDL.GamepadButton.DPadDown);
        UpdateGamepadButton(data, io, ImGuiKey.GamepadL1, SDL.GamepadButton.LeftShoulder);
        UpdateGamepadButton(data, io, ImGuiKey.GamepadR1, SDL.GamepadButton.RightShoulder);

        UpdateGamepadAnalog(data, io, ImGuiKey.GamepadL2, SDL.GamepadAxis.LeftTrigger, 0.0f, 32767);
        UpdateGamepadAnalog(data, io, ImGuiKey.GamepadR2, SDL.GamepadAxis.RightTrigger, 0.0f, 32767);

        UpdateGamepadButton(data, io, ImGuiKey.GamepadL3, SDL.GamepadButton.LeftStick);
        UpdateGamepadButton(data, io, ImGuiKey.GamepadR3, SDL.GamepadButton.RightStick);

        UpdateGamepadAnalog(data, io, ImGuiKey.GamepadLStickLeft, SDL.GamepadAxis.LeftX, -thumbDeadZone, -32768);
        UpdateGamepadAnalog(data, io, ImGuiKey.GamepadLStickRight, SDL.GamepadAxis.LeftX, thumbDeadZone, 32767);
        UpdateGamepadAnalog(data, io, ImGuiKey.GamepadLStickUp, SDL.GamepadAxis.LeftY, -thumbDeadZone, -32768);
        UpdateGamepadAnalog(data, io, ImGuiKey.GamepadLStickDown, SDL.GamepadAxis.LeftY, thumbDeadZone, 32767);

        UpdateGamepadAnalog(data, io, ImGuiKey.GamepadRStickLeft, SDL.GamepadAxis.RightX, -thumbDeadZone, -32768);
        UpdateGamepadAnalog(data, io, ImGuiKey.GamepadRStickRight, SDL.GamepadAxis.RightX, thumbDeadZone, 32767);
        UpdateGamepadAnalog(data, io, ImGuiKey.GamepadRStickUp, SDL.GamepadAxis.RightY, -thumbDeadZone, -32768);
        UpdateGamepadAnalog(data, io, ImGuiKey.GamepadRStickDown, SDL.GamepadAxis.RightY, thumbDeadZone, 32767);
    }

    public static void UpdateMonitors()
    {
        PlatformData bd = Data;
        ImGuiPlatformIOPtr platformio = ImGui.GetPlatformIO();
        platformio.Monitors.Resize(0);
        bd.WantUpdateMonitors = false;

        var displays = SDL.GetDisplays(out int displayCount);
        for (int n = 0; n < displayCount; n++)
        {
            // Warning: the validity of monitor DPI information on Windows depends on the application DPI awareness settings, which generally needs to be set in the manifest or at runtime.
            var displayID = displays[n];
            ImGuiPlatformMonitor monitor = new ImGuiPlatformMonitor();
            SDL.GetDisplayBounds(displayID, out SDL.Rect r);
            monitor.MainPos = monitor.WorkPos = new Vector2(r.X, r.Y);
            monitor.MainSize = monitor.WorkSize = new Vector2(r.W, r.H);
            if (SDL.GetDisplayUsableBounds(displayID, out SDL.Rect r2) && r2.W > 0 && r2.H > 0)
            {
                monitor.WorkPos = new Vector2(r2.X, r2.Y);
                monitor.WorkSize = new Vector2(r2.W, r2.H);
            }
            monitor.DpiScale = SDL.GetDisplayContentScale(displayID); // See https://wiki.libsdl.org/SDL3/README-highdpi for details.
            monitor.PlatformHandle = (void*)n;
            if (monitor.DpiScale <= 0.0f)
                continue; // Some accessibility applications are declaring virtual monitors with a DPI of 0, see #7902.
            platformio.Monitors.PushBack(monitor);
        }
    }

    private static ImGuiKey KeyEventToImGui(SDL.Keycode keycode, SDL.Scancode scancode)
    {
        return scancode switch
        {
            SDL.Scancode.Kp0        => ImGuiKey.Keypad0,
            SDL.Scancode.Kp1        => ImGuiKey.Keypad1,
            SDL.Scancode.Kp2        => ImGuiKey.Keypad2,
            SDL.Scancode.Kp3        => ImGuiKey.Keypad3,
            SDL.Scancode.Kp4        => ImGuiKey.Keypad4,
            SDL.Scancode.Kp5        => ImGuiKey.Keypad5,
            SDL.Scancode.Kp6        => ImGuiKey.Keypad6,
            SDL.Scancode.Kp7        => ImGuiKey.Keypad7,
            SDL.Scancode.Kp8        => ImGuiKey.Keypad8,
            SDL.Scancode.Kp9        => ImGuiKey.Keypad9,
            SDL.Scancode.KpPeriod   => ImGuiKey.KeypadDecimal,
            SDL.Scancode.KpDivide   => ImGuiKey.KeypadDivide,
            SDL.Scancode.KpMultiply => ImGuiKey.KeypadMultiply,
            SDL.Scancode.KpMinus    => ImGuiKey.KeypadSubtract,
            SDL.Scancode.KpPlus     => ImGuiKey.KeypadAdd,
            SDL.Scancode.KpEnter    => ImGuiKey.KeypadEnter,
            SDL.Scancode.KpEquals   => ImGuiKey.KeypadEqual,
            _ => keycode switch
            {
                SDL.Keycode.Tab          => ImGuiKey.Tab,
                SDL.Keycode.Left         => ImGuiKey.LeftArrow,
                SDL.Keycode.Right        => ImGuiKey.RightArrow,
                SDL.Keycode.Up           => ImGuiKey.UpArrow,
                SDL.Keycode.Down         => ImGuiKey.DownArrow,
                SDL.Keycode.Pageup       => ImGuiKey.PageUp,
                SDL.Keycode.Pagedown     => ImGuiKey.PageDown,
                SDL.Keycode.Home         => ImGuiKey.Home,
                SDL.Keycode.End          => ImGuiKey.End,
                SDL.Keycode.Insert       => ImGuiKey.Insert,
                SDL.Keycode.Delete       => ImGuiKey.Delete,
                SDL.Keycode.Backspace    => ImGuiKey.Backspace,
                SDL.Keycode.Space        => ImGuiKey.Space,
                SDL.Keycode.Return       => ImGuiKey.Enter,
                SDL.Keycode.Escape       => ImGuiKey.Escape,
                SDL.Keycode.Apostrophe   => ImGuiKey.Apostrophe,
                SDL.Keycode.Comma        => ImGuiKey.Comma,
                SDL.Keycode.Minus        => ImGuiKey.Minus,
                SDL.Keycode.Period       => ImGuiKey.Period,
                SDL.Keycode.Slash        => ImGuiKey.Slash,
                SDL.Keycode.Semicolon    => ImGuiKey.Semicolon,
                SDL.Keycode.Equals       => ImGuiKey.Equal,
                SDL.Keycode.LeftBracket  => ImGuiKey.LeftBracket,
                SDL.Keycode.Backslash    => ImGuiKey.Backslash,
                SDL.Keycode.RightBracket => ImGuiKey.RightBracket,
                SDL.Keycode.Grave        => ImGuiKey.GraveAccent,
                SDL.Keycode.Capslock     => ImGuiKey.CapsLock,
                SDL.Keycode.ScrollLock   => ImGuiKey.ScrollLock,
                SDL.Keycode.NumLockClear => ImGuiKey.NumLock,
                SDL.Keycode.PrintScreen  => ImGuiKey.PrintScreen,
                SDL.Keycode.Pause        => ImGuiKey.Pause,
                SDL.Keycode.LCtrl        => ImGuiKey.LeftCtrl,
                SDL.Keycode.LShift       => ImGuiKey.LeftShift,
                SDL.Keycode.LAlt         => ImGuiKey.LeftAlt,
                SDL.Keycode.LGui         => ImGuiKey.LeftSuper,
                SDL.Keycode.RCtrl        => ImGuiKey.RightCtrl,
                SDL.Keycode.RShift       => ImGuiKey.RightShift,
                SDL.Keycode.RAlt         => ImGuiKey.RightAlt,
                SDL.Keycode.RGUI         => ImGuiKey.RightSuper,
                SDL.Keycode.Application  => ImGuiKey.Menu,
                SDL.Keycode.Alpha0       => ImGuiKey.Key0,
                SDL.Keycode.Alpha1       => ImGuiKey.Key1,
                SDL.Keycode.Alpha2       => ImGuiKey.Key2,
                SDL.Keycode.Alpha3       => ImGuiKey.Key3,
                SDL.Keycode.Alpha4       => ImGuiKey.Key4,
                SDL.Keycode.Alpha5       => ImGuiKey.Key5,
                SDL.Keycode.Alpha6       => ImGuiKey.Key6,
                SDL.Keycode.Alpha7       => ImGuiKey.Key7,
                SDL.Keycode.Alpha8       => ImGuiKey.Key8,
                SDL.Keycode.Alpha9       => ImGuiKey.Key9,
                SDL.Keycode.A            => ImGuiKey.A,
                SDL.Keycode.B            => ImGuiKey.B,
                SDL.Keycode.C            => ImGuiKey.C,
                SDL.Keycode.D            => ImGuiKey.D,
                SDL.Keycode.E            => ImGuiKey.E,
                SDL.Keycode.F            => ImGuiKey.F,
                SDL.Keycode.G            => ImGuiKey.G,
                SDL.Keycode.H            => ImGuiKey.H,
                SDL.Keycode.I            => ImGuiKey.I,
                SDL.Keycode.J            => ImGuiKey.J,
                SDL.Keycode.K            => ImGuiKey.K,
                SDL.Keycode.L            => ImGuiKey.L,
                SDL.Keycode.M            => ImGuiKey.M,
                SDL.Keycode.N            => ImGuiKey.N,
                SDL.Keycode.O            => ImGuiKey.O,
                SDL.Keycode.P            => ImGuiKey.P,
                SDL.Keycode.Q            => ImGuiKey.Q,
                SDL.Keycode.R            => ImGuiKey.R,
                SDL.Keycode.S            => ImGuiKey.S,
                SDL.Keycode.T            => ImGuiKey.T,
                SDL.Keycode.U            => ImGuiKey.U,
                SDL.Keycode.V            => ImGuiKey.V,
                SDL.Keycode.W            => ImGuiKey.W,
                SDL.Keycode.X            => ImGuiKey.X,
                SDL.Keycode.Y            => ImGuiKey.Y,
                SDL.Keycode.Z            => ImGuiKey.Z,
                SDL.Keycode.F1           => ImGuiKey.F1,
                SDL.Keycode.F2           => ImGuiKey.F2,
                SDL.Keycode.F3           => ImGuiKey.F3,
                SDL.Keycode.F4           => ImGuiKey.F4,
                SDL.Keycode.F5           => ImGuiKey.F5,
                SDL.Keycode.F6           => ImGuiKey.F6,
                SDL.Keycode.F7           => ImGuiKey.F7,
                SDL.Keycode.F8           => ImGuiKey.F8,
                SDL.Keycode.F9           => ImGuiKey.F9,
                SDL.Keycode.F10          => ImGuiKey.F10,
                SDL.Keycode.F11          => ImGuiKey.F11,
                SDL.Keycode.F12          => ImGuiKey.F12,
                SDL.Keycode.F13          => ImGuiKey.F13,
                SDL.Keycode.F14          => ImGuiKey.F14,
                SDL.Keycode.F15          => ImGuiKey.F15,
                SDL.Keycode.F16          => ImGuiKey.F16,
                SDL.Keycode.F17          => ImGuiKey.F17,
                SDL.Keycode.F18          => ImGuiKey.F18,
                SDL.Keycode.F19          => ImGuiKey.F19,
                SDL.Keycode.F20          => ImGuiKey.F20,
                SDL.Keycode.F21          => ImGuiKey.F21,
                SDL.Keycode.F22          => ImGuiKey.F22,
                SDL.Keycode.F23          => ImGuiKey.F23,
                SDL.Keycode.F24          => ImGuiKey.F24,
                SDL.Keycode.AcBack       => ImGuiKey.AppBack,
                SDL.Keycode.AcForward    => ImGuiKey.AppForward,
                _                        => ImGuiKey.None
            }
        };

    }

    public static nint GetClipboardText(nint ctx)
    {
        PlatformData data = Data;

        string text = SDL.GetClipboardText();
        data.ClipboardTextData = Marshal.StringToHGlobalAnsi(text ?? string.Empty);
        return data.ClipboardTextData;
    }

    public static void SetClipboardText(nint ctx, nint text)
    {
        string? managedText = Marshal.PtrToStringAnsi(text);
        if (managedText != null)
        {
            SDL.SetClipboardText(managedText);
        }
    }

    private static void SetImeData(nint ctx, nint userData, nint imeData)
    {
        PlatformData data = Data;
        data.ImeData = Marshal.PtrToStructure<ImGuiPlatformImeData>(imeData);
        data.ImeDirty = true;
    }

    public static void UpdateIme(PlatformData data)
    {
        ImGuiPlatformImeData imeData = data.ImeData;
        nint window = SDL.GetKeyboardFocus();

        // Stop previous input
        if ((imeData.WantVisible != 1 || data.ImeWindow != window) && data.ImeWindow != nint.Zero)
        {
            SDL.StopTextInput(data.ImeWindow);
            data.ImeWindow = nint.Zero;
        }
        if (!data.ImeDirty && data.ImeWindow == window || window == nint.Zero)
            return;

        // Start/update current input
        data.ImeDirty = false;
        if (imeData.WantVisible == 1)
        {
            SDL.Rect r = new SDL.Rect
            {
                X = (int)imeData.InputPos.X,
                Y = (int)imeData.InputPos.Y,
                W = 1,
                H = (int)imeData.InputLineHeight
            };
            SDL.SetTextInputArea(window, r, 0);
            data.ImeWindow = window;
        }
        if (!SDL.TextInputActive(window) && imeData.WantVisible == 1)
            SDL.StartTextInput(window);
    }

    private static bool OpenInShell(nint ctx, nint url)
    {
        string managedUrl = Marshal.PtrToStringUTF8(url) ?? string.Empty;
        return SDL.OpenURL(managedUrl);
    }

    // !! This is sorta fucked
    // public static void UpdateKeyModifiers(SDL.Keymod keymods)
    // {
    //     ImGuiIOPtr io = ImGui.GetIO();
    //     io.KeyCtrl = keymods.HasFlag(SDL.Keymod.LCtrl) || keymods.HasFlag(SDL.Keymod.RCtrl);
    //     io.KeyShift = keymods.HasFlag(SDL.Keymod.LShift) || keymods.HasFlag(SDL.Keymod.RShift);
    //     io.KeyAlt = keymods.HasFlag(SDL.Keymod.LAlt) || keymods.HasFlag(SDL.Keymod.RAlt);
    //     io.KeySuper = keymods.HasFlag(SDL.Keymod.LGUI) || keymods.HasFlag(SDL.Keymod.RGUI);
    // }

    private static void UpdateKeyModifiers(SDL.Keymod mod)
    {
        ImGuiIOPtr io = ImGui.GetIO();
        io.AddKeyEvent(ImGuiKey.ModCtrl, (mod & SDL.Keymod.Ctrl) != 0);
        io.AddKeyEvent(ImGuiKey.ModShift, (mod & SDL.Keymod.Shift) != 0);
        io.AddKeyEvent(ImGuiKey.ModAlt, (mod & SDL.Keymod.Alt) != 0);
        io.AddKeyEvent(ImGuiKey.ModSuper, (mod & SDL.Keymod.GUI) != 0);
    }

    private static void CreateWindow(ImGuiViewportPtr viewport)
    {
        Program.Logger.Log(null);
        PlatformData bd = Data;

        ViewPortData vd = new ViewPortData();
        viewport.PlatformUserData = ImGuiUserData<ViewPortData>.Store(vd);

        SDL.WindowFlags flags = SDL.WindowFlags.Hidden;

        flags |= SDL.GetWindowFlags(bd.Window) & SDL.WindowFlags.HighPixelDensity;

        string? videoDriver = SDL.GetCurrentVideoDriver();
        bool isWayland = string.Equals(videoDriver, "wayland", StringComparison.OrdinalIgnoreCase);

        if ((viewport.Flags & ImGuiViewportFlags.NoDecoration) != 0 && !isWayland)
        {
            flags |= SDL.WindowFlags.Borderless;
        }
        else
        {
            flags |= SDL.WindowFlags.Resizable;
        }

        if ((viewport.Flags & ImGuiViewportFlags.NoTaskBarIcon) != 0)
        {
            flags |= SDL.WindowFlags.Utility;
        }

        if ((viewport.Flags & ImGuiViewportFlags.TopMost) != 0)
        {
            flags |= SDL.WindowFlags.AlwaysOnTop;
        }

        vd.Window = SDL.CreateWindow("Untitled", (int)viewport.Size.X, (int)viewport.Size.Y, flags);

        ImGuiViewportPtr? parentViewport = viewport.ParentViewportId != 0 ? ImGui.FindViewportByID(viewport.ParentViewportId) : null;
        if (parentViewport != null && parentViewport.Value.Handle != null)
        {
            vd.ParentWindow = GetSDLWindowFromViewport(parentViewport.Value);
            if (vd.ParentWindow != nint.Zero)
                SDL.SetWindowParent(vd.Window, vd.ParentWindow);
        }

        SDL.SetWindowPosition(vd.Window, (int)viewport.Pos.X, (int)viewport.Pos.Y);
        vd.WindowOwned = true;

        SetupPlatformHandles(viewport, vd.Window);

        Program.Logger.Log($"SDL Window: {vd.Window} {vd.WindowID} {viewport.Pos.X} {viewport.Pos.Y} {viewport.Size.X} {viewport.Size.Y}");

#if WINDOWS
    viewport.PlatformHandleRaw = SDL.GetPointerProperty(
        SDL.GetWindowProperties(vd.Window),
        SDL.Properties.WindowWin32HWNDPointer,
        nint.Zero
    ).ToPointer();
#endif
    }

    private static void DestroyWindow(ImGuiViewportPtr viewport)
    {
        Program.Logger.Log(null);
        ViewPortData? vd = ImGuiUserData<ViewPortData>.Get(viewport.PlatformUserData);

        if (vd != null)
        {
            if (vd.Window != nint.Zero && vd.WindowOwned)
            {
                SDL.DestroyWindow(vd.Window);
            }
        }

        ImGuiUserData<ViewPortData>.Free(viewport.PlatformUserData);

        viewport.PlatformUserData = null;
        viewport.PlatformHandle = null;
        viewport.PlatformHandleRaw = null;

        Program.Logger.Log(null);
    }

    private static void ShowWindow(ImGuiViewportPtr viewport)
    {
        Program.Logger.Log(null);
        ViewPortData vd = ImGuiUserData<ViewPortData>.Get(viewport.PlatformUserData)!;

        string? oldHint = SDL.GetHint(SDL.Hints.WindowActivateWhenShown);

        SDL.SetHint(SDL.Hints.WindowActivateWhenShown, ((viewport.Flags & ImGuiViewportFlags.NoFocusOnAppearing) != 0) ? "0" : "1");

        SDL.ShowWindow(vd.Window);

        SDL.SetHint(SDL.Hints.WindowActivateWhenShown, oldHint);
        Program.Logger.Log(null);
    }

    private static void UpdateWindow(ImGuiViewportPtr viewport)
    {
        Program.Logger.Log(null);
        ViewPortData vd = ImGuiUserData<ViewPortData>.Get(viewport.PlatformUserData)!;

        if ((viewport.Flags & ImGuiViewportFlags.TopMost) != 0)
        {
            SDL.SetWindowAlwaysOnTop(vd.Window, true);
        }
        else
        {
            SDL.SetWindowAlwaysOnTop(vd.Window, false);
        }
        Program.Logger.Log(null);
    }

    private static Vector2 GetWindowPos(ImGuiViewportPtr viewport)
    {
        ViewPortData vd = ImGuiUserData<ViewPortData>.Get(viewport.PlatformUserData)!;

        SDL.GetWindowPosition(vd.Window, out int x, out int y);
        
        // Program.Logger.Log(null);

        return new Vector2(x, y);
    }

    private static void SetWindowPos(ImGuiViewportPtr viewport, Vector2 pos)
    {
        ViewPortData vd = ImGuiUserData<ViewPortData>.Get(viewport.PlatformUserData)!;

        SDL.SetWindowPosition(vd.Window, (int)pos.X, (int)pos.Y);
        Program.Logger.Log(null);
    }

    private static Vector2 GetWindowSize(ImGuiViewportPtr viewport)
    {
        ViewPortData vd = ImGuiUserData<ViewPortData>.Get(viewport.PlatformUserData)!;

        SDL.GetWindowSize(vd.Window, out int w, out int h);

        // Program.Logger.Log(null);
        return new Vector2(w, h);
    }

    private static void SetWindowSize(ImGuiViewportPtr viewport, Vector2 size)
    {
        ViewPortData vd = ImGuiUserData<ViewPortData>.Get(viewport.PlatformUserData)!;

        SDL.SetWindowSize(vd.Window, (int)size.X, (int)size.Y);
        Program.Logger.Log(null);
    }

    private static Vector2 GetWindowFramebufferScale(ImGuiViewportPtr viewport)
    {
        ViewPortData vd = ImGuiUserData<ViewPortData>.Get(viewport.PlatformUserData)!;

        GetWindowSizeAndFramebufferScale(vd.Window, out Vector2 framebufferSize, out Vector2 framebufferScale);
        // Program.Logger.Log(null);

        return framebufferScale;
    }

    private static void SetWindowTitle(ImGuiViewportPtr viewport, string title)
    {
        ViewPortData vd = ImGuiUserData<ViewPortData>.Get(viewport.PlatformUserData)!;

        SDL.SetWindowTitle(vd.Window, title);
        Program.Logger.Log(null);
    }

    private static void SetWindowAlpha(ImGuiViewportPtr viewport, float alpha)
    {
        ViewPortData vd = ImGuiUserData<ViewPortData>.Get(viewport.PlatformUserData)!;

        SDL.SetWindowOpacity(vd.Window, alpha);
        Program.Logger.Log(null);
    }

    private static void SetWindowFocus(ImGuiViewportPtr viewport)
    {
        ViewPortData vd = ImGuiUserData<ViewPortData>.Get(viewport.PlatformUserData)!;

        SDL.RaiseWindow(vd.Window);
        Program.Logger.Log(null);
    }

    private static bool GetWindowFocus(ImGuiViewportPtr viewport)
    {
        ViewPortData vd = ImGuiUserData<ViewPortData>.Get(viewport.PlatformUserData)!;
        // Program.Logger.Log(null);

        return (SDL.GetWindowFlags(vd.Window) & SDL.WindowFlags.InputFocus) != 0;
    }

    private static bool GetWindowMinimized(ImGuiViewportPtr viewport)
    {
        ViewPortData vd = ImGuiUserData<ViewPortData>.Get(viewport.PlatformUserData)!;
        // Program.Logger.Log(null);

        return (SDL.GetWindowFlags(vd.Window) & SDL.WindowFlags.Minimized) != 0;
    }

    private static void RenderWindow(ImGuiViewportPtr viewport)
    {
        // Renderer-backed viewport rendering is handled by ImGuiSDL3Renderer.
        Program.Logger.Log(null);
    }

    private static void SwapBuffers(ImGuiViewportPtr viewport)
    {
        // Renderer-backed viewport presentation is handled by ImGuiSDL3Renderer.
        Program.Logger.Log(null);
    }


    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate void CreateWindowDelegatelFn(ImGuiViewportPtr ctx);

    private static readonly CreateWindowDelegatelFn CreateWindowDelegate = CreateWindow;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate void DestroyWindowDelegatelFn(ImGuiViewportPtr ctx);

    private static readonly DestroyWindowDelegatelFn DestroyWindowDelegate = DestroyWindow;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate void ShowWindowDelegatelFn(ImGuiViewportPtr ctx);

    private static readonly ShowWindowDelegatelFn ShowWindowDelegate = ShowWindow;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate void UpdateWindowDelegatelFn(ImGuiViewportPtr ctx);

    private static readonly UpdateWindowDelegatelFn UpdateWindowDelegate = UpdateWindow;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate void SetWindowPosDelegatelFn(ImGuiViewportPtr ctx, Vector2 pos);

    private static readonly SetWindowPosDelegatelFn SetWindowPosDelegate = SetWindowPos;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate Vector2 GetWindowPosDelegatelFn(ImGuiViewportPtr ctx);

    private static readonly GetWindowPosDelegatelFn GetWindowPosDelegate = GetWindowPos;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate void SetWindowSizeDelegatelFn(ImGuiViewportPtr ctx, Vector2 size);

    private static readonly SetWindowSizeDelegatelFn SetWindowSizeDelegate = SetWindowSize;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate Vector2 GetWindowSizeDelegateFn(ImGuiViewportPtr ctx);

    private static readonly GetWindowSizeDelegateFn GetWindowSizeDelegate = GetWindowSize;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate Vector2 GetWindowFramebufferScaleDelegatelFn(ImGuiViewportPtr ctx);

    private static readonly GetWindowFramebufferScaleDelegatelFn GetWindowFramebufferScaleDelegate = GetWindowFramebufferScale;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate void SetWindowFocusDelegatelFn(ImGuiViewportPtr ctx);

    private static readonly SetWindowFocusDelegatelFn SetWindowFocusDelegate = SetWindowFocus;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate bool GetWindowFocusDelegatelFn(ImGuiViewportPtr ctx);

    private static readonly GetWindowFocusDelegatelFn GetWindowFocusDelegate = GetWindowFocus;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate bool GetWindowMinimizedDelegatelFn(ImGuiViewportPtr ctx);

    private static readonly GetWindowMinimizedDelegatelFn GetWindowMinimizedDelegate = GetWindowMinimized;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate void SetWindowTitleDelegatelFn(ImGuiViewportPtr ctx, string title);

    private static readonly SetWindowTitleDelegatelFn SetWindowTitleDelegate = SetWindowTitle;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate void RenderWindowDelegatelFn(ImGuiViewportPtr ctx);

    private static readonly RenderWindowDelegatelFn RenderWindowDelegate = RenderWindow;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate void SwapBuffersDelegatelFn(ImGuiViewportPtr ctx);

    private static readonly SwapBuffersDelegatelFn SwapBuffersDelegate = SwapBuffers;

    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
    private delegate void SetWindowAlphaDelegatelFn(ImGuiViewportPtr ctx, float alpha);

    private static readonly SetWindowAlphaDelegatelFn SetWindowAlphaDelegate = SetWindowAlpha;

    private static void InitMultiViewportSupport(nint window)
    {
        Program.Logger.Log(null);
        
        ImGuiPlatformIOPtr platformIO = ImGui.GetPlatformIO();

        platformIO.PlatformCreateWindow = (void*)Marshal.GetFunctionPointerForDelegate(CreateWindowDelegate);
        platformIO.PlatformDestroyWindow = (void*)Marshal.GetFunctionPointerForDelegate(DestroyWindowDelegate);
        platformIO.PlatformShowWindow = (void*)Marshal.GetFunctionPointerForDelegate(ShowWindowDelegate);
        platformIO.PlatformSetWindowPos = (void*)Marshal.GetFunctionPointerForDelegate(SetWindowPosDelegate);
        platformIO.PlatformGetWindowPos = (void*)Marshal.GetFunctionPointerForDelegate(GetWindowPosDelegate);
        platformIO.PlatformSetWindowSize = (void*)Marshal.GetFunctionPointerForDelegate(SetWindowSizeDelegate);
        platformIO.PlatformGetWindowSize = (void*)Marshal.GetFunctionPointerForDelegate(GetWindowSizeDelegate);
        platformIO.PlatformSetWindowFocus = (void*)Marshal.GetFunctionPointerForDelegate(SetWindowFocusDelegate);
        platformIO.PlatformGetWindowFocus = (void*)Marshal.GetFunctionPointerForDelegate(GetWindowFocusDelegate);
        platformIO.PlatformGetWindowMinimized = (void*)Marshal.GetFunctionPointerForDelegate(GetWindowMinimizedDelegate);
        platformIO.PlatformSetWindowTitle = (void*)Marshal.GetFunctionPointerForDelegate(SetWindowTitleDelegate);
        platformIO.PlatformSetWindowAlpha = (void*)Marshal.GetFunctionPointerForDelegate(SetWindowAlphaDelegate);
        platformIO.PlatformUpdateWindow = (void*)Marshal.GetFunctionPointerForDelegate(UpdateWindowDelegate);
        platformIO.PlatformGetWindowFramebufferScale = (void*)Marshal.GetFunctionPointerForDelegate(GetWindowFramebufferScaleDelegate);

        ImGuiViewportPtr mainViewport = ImGui.GetMainViewport();

        ViewPortData vd = new ViewPortData
        {
            Window = window,
            Renderer = Data.Renderer,
            WindowID = SDL.GetWindowID(window),
            WindowOwned = false,
            RendererOwned = false
        };

        mainViewport.PlatformUserData = ImGuiUserData<ViewPortData>.Store(vd);
        mainViewport.PlatformHandle = (void*)(nint)SDL.GetWindowID(window);
        
        Program.Logger.Log(null);

#if WINDOWS
    mainViewport.PlatformHandleRaw = SDL.GetPointerProperty(
        SDL.GetWindowProperties(window),
        SDL.Properties.WindowWin32HWNDPointer,
        nint.Zero
    ).ToPointer();
#endif
    }

    public static ImGuiViewportPtr? GetViewportForWindowId(uint id)
    {
        return ImGui.FindViewportByPlatformHandle((void*)(nint)id);
    }

    private static nint GetSDLWindowFromViewport(ImGuiViewportPtr viewport)
    {
        return SDL.GetWindowFromID((uint)(nint)viewport.PlatformHandle);
    }

    private static void SetupPlatformHandles(ImGuiViewportPtr viewport, nint window)
    {
        viewport.PlatformHandle = (void*)(nint)SDL.GetWindowID(window);
        viewport.PlatformHandleRaw = (void*)nint.Zero;
#if _WIN32 && !__WINTR__
        SDL.GetPointerProperty(SDL.GetWindowProperties(window), SDL.Props.WindowWin32HWNDPointer, 0);
#elif __APPLE__ && SDL_VIDEO_DRIVER_COCOA
        SDL.GetPointerProperty(SDL.GetWindowProperties(window), SDL.Props.WindowCocoaWindow, 0);
#endif
    }
    
    public static void Dispose()
    {
        PlatformData? data = Data;

        if (data != null)
        {
            foreach (nint cursor in data.MouseCursors)
            {
                if (cursor != nint.Zero)
                    SDL.DestroyCursor(cursor);
            }
        }

        ImGuiIOPtr io = ImGui.GetIO();
        ImGuiPlatformIOPtr platformIo = ImGui.GetPlatformIO();
        platformIo.PlatformGetClipboardTextFn = null;
        platformIo.PlatformSetClipboardTextFn = null;
        platformIo.PlatformSetImeDataFn = null;
        platformIo.PlatformOpenInShellFn = null;
        ImGuiUserData<PlatformData>.Free(io.BackendPlatformUserData);
        io.BackendPlatformUserData = null;
    }
}

public enum GamepadMode
{
    AutoFirst,
    AutoAll,
    Manual
}

public enum MouseCaptureMode
{
    Enabled,
    EnabledAfterDrag,
    Disabled
}

public unsafe static class ImGuiUserData<T> where T : class
{
    public static void* Store(T value)
    {
        if (value == null)
            return null;

        GCHandle handle = GCHandle.Alloc(value, GCHandleType.Normal);
        return (void*)GCHandle.ToIntPtr(handle);
    }

    public static T Get(void* ptr)
    {
        if (ptr == null)
            return null;

        GCHandle handle = GCHandle.FromIntPtr((nint)ptr);
        return (T)handle.Target;
    }

    public static void Free(void* ptr)
    {
        if (ptr == null)
            return;

        GCHandle handle = GCHandle.FromIntPtr((nint)ptr);

        if (handle.IsAllocated)
            handle.Free();
    }
}