pub const Impl = struct {
    allocator: std.mem.Allocator,
    device: *gpu.GPUDevice = undefined,

    drawData: [*c]ig.DrawData = undefined,
    rendererDebug: bool = true,
    context: *ig.Context = undefined,

    beginCount: u32 = 0,

    pub var NeonObjectTable: core.EngineObjectVTable = core.EngineObjectVTable.from(@This(), "imgui.BackendImpl");

    pub const Settings = struct {
        x: u32 = 0,
    };

    // renderer plugin
    pub fn create(allocator: std.mem.Allocator) !*@This() {
        const self = try allocator.create(@This());

        self.* = .{
            .allocator = allocator,
        };

        return self;
    }

    const ImguiArgs = struct { imguiIni: []const u8 = "imgui.ini" };

    pub fn setup(self: *@This()) !void {
        core.graphics_log("imgui startup", .{});
        self.device = rend.context().device;
        try rend.registerRendererObject(@This(), self);

        const args = try core.ParseArgs(ImguiArgs);

        c.Imgui_SDL3_Init(@ptrCast(platform.getInstance().window), @ptrCast(self.device));
        ig.getIO().?.ini_file_name = @ptrCast(args.imguiIni.ptr);
        ig.loadIniSettingsFromDisk(@ptrCast(args.imguiIni.ptr));

        try platform.getInstance().addSDLProcessFunction(processSDLEvents);
        core.engine_log("using imgui ini: {s}", .{args.imguiIni});

        self.context = ig.getCurrentContext().?;
        self.setupBeginCount();
    }

    pub fn setupBeginCount(self: *@This()) void {
        ig.setBeginCount(&self.beginCount);
    }

    pub fn processSDLEvents(event: *sdl3.Event) void {
        if (platform.getInstance().enableImguiEvents) {
            c.Imgui_SDL3_ProcessEvent(@ptrCast(event));
        }
    }

    pub fn onPreDraw(p: *anyopaque, cmd: *gpu.GPUCommandBuffer) void {
        const self: *@This() = @ptrCast(@alignCast(p));
        platform.context().imguiMouseConsumed = ig.isWindowHovered(.{ .any_window = true });

        const count = self.beginCount;
        while (self.beginCount > 0) {
            ig.end();
        }
        if (count > 0) {
            _ = ig.begin("error", null, .{});
            ig.textf("IMGUI ERORR", .{});
            core.engine_logs("error");
            ig.end();
        }
        ig.render();

        if (platform.getInstance().imguiVisible) {
            self.drawData = ig.getDrawData();

            c.Imgui_SDL3_PrepareRender(@ptrCast(self.drawData), @ptrCast(cmd));
        }
    }

    pub fn postRender(p: *anyopaque, cmd: *gpu.GPUCommandBuffer) void {
        const self: *@This() = @ptrCast(@alignCast(p));
        if (platform.getInstance().imguiVisible) {

            //const renderpass = cmd.beginGPURenderPass(color_target_infos: [*c]const GPUColorTargetInfo, num_color_targets: u32, depth_stencil_target_info: [*c]const GPUDepthStencilTargetInfo);
            var targetInfo: gpu.GPUColorTargetInfo = std.mem.zeroes(gpu.GPUColorTargetInfo);
            targetInfo.texture = rend.context().state.swapchainTargetTexture.?;
            targetInfo.clear_color = .{ .r = 0.0, .g = 0.0, .b = 0.0, .a = 0.0 };
            targetInfo.load_op = .loadopLoad;
            targetInfo.store_op = .storeopStore;
            const renderpass = cmd.beginGPURenderPass(&targetInfo, 1, null);

            c.ImGui_SDLGPU3_RenderDrawData(
                @ptrCast(self.drawData),
                @ptrCast(cmd),
                @ptrCast(renderpass),
            );

            renderpass.endGPURenderPass();
        }
    }

    pub fn preTick(self: *@This(), dt: f64) core.EngineDataEventError!void {
        _ = self;

        c.Imgui_SDL3_NewFrame();
        c.igNewFrame();

        _ = ig.dockSpaceOverViewport(ig.getMainViewport(), .{ .passthru_central_node = true }, null);
        _ = dt;
    }

    // renderer plugin
    pub fn destroy(self: *@This()) void {
        self.allocator.destroy(self);
    }
};
const c = @import("cimgui").c;
const ig = @import("cimgui");
const sdl3 = @import("sdl3");
const gpu = sdl3.gpu;
const rend = @import("rend");
const platform = @import("platform");
const std = @import("std");
const core = @import("core");