//
// Created by atdunbg on 2026/9/23.
//

#include <Engine/Renderer/Passes/ImGuiPass.h>
#include <Engine/ImGui/ImGuiLayer.h>

namespace Engine::Passes
{
    void ImGuiPass::Register(RG::RenderGraph& rg)
    {
        rg.AddPass("ImGui", [this](RG::RenderGraphContext& ctx) {
            const vk::CommandBuffer cmd = ctx.cmd;

            // loadOp 按显示模式分支：Direct = blit 已铺满场景（Load 叠加）；
            // Viewport = 本 pass 是唯一写入者（Clear 为"桌面底色"）
            const bool direct = (m_Frame.displayMode == kDisplayDirect);

            vk::ClearValue clearValue;
            clearValue.color = vk::ClearColorValue(
                std::array<float, 4>{0.04f, 0.045f, 0.06f, 1.0f});

            vk::RenderingAttachmentInfo colorAttachment;
            colorAttachment.setImageView(ctx.View(m_Backbuffer))
                           .setImageLayout(vk::ImageLayout::eColorAttachmentOptimal)
                           .setLoadOp(direct ? vk::AttachmentLoadOp::eLoad
                                             : vk::AttachmentLoadOp::eClear)
                           .setStoreOp(vk::AttachmentStoreOp::eStore)
                           .setClearValue(clearValue);

            vk::RenderingInfo renderingInfo;
            // 渲染区域 = backbuffer 物理尺寸（窗口大小），不是 ctx.extent
            //（= RG 目标尺寸 = 场景渲染分辨率）。Editor 视口模式下场景链
            // 按面板尺寸渲染，而 backbuffer 是全窗口——若跟随目标尺寸，
            // 整个 ImGui 会被裁剪到面板大小
            renderingInfo.setRenderArea({{0, 0}, ctx.Extent(m_Backbuffer)})
                         .setLayerCount(1)
                         .setColorAttachments(colorAttachment);

            cmd.beginRendering(renderingInfo);

            if (*m_Layer) {
                (*m_Layer)->RenderDrawData(cmd);
            }

            cmd.endRendering();
        }).Write(m_Backbuffer, RG::ResourceUse::ColorAttachment)
          // 场景纹理在本 pass 内被 ImGui::Image 的描述符采样：声明读让 RG
          // 补 ColorAttachment→ShaderRead barrier，并推导 eSampled usage
          .Read(m_PresentTarget, RG::ResourceUse::ShaderRead,
                vk::ShaderStageFlagBits::eFragment);
    }

} // namespace Engine::Passes