#include "Rendering/D3D12/D3D12WindowSwapChainPresenter.h"

namespace XCEngine::UI::Editor::Host {

using ::XCEngine::RHI::D3D12SwapChain;
using ::XCEngine::RHI::D3D12Texture;
using ::XCEngine::RHI::Format;
using ::XCEngine::RHI::ResourceStates;
using ::XCEngine::RHI::ResourceViewDesc;
using ::XCEngine::RHI::ResourceViewDimension;

void D3D12WindowSwapChainPresenter::ReleaseBackBufferCommandReferences() {
    if (m_hostDevice == nullptr) {
        return;
    }

    for (std::uint32_t frameIndex = 0u;
         frameIndex < D3D12HostDevice::kFrameContextCount;
         ++frameIndex) {
        auto* commandList = m_hostDevice->GetCommandList(frameIndex);
        if (commandList == nullptr) {
            continue;
        }

        commandList->Reset();
        commandList->Close();
    }
}

void D3D12WindowSwapChainPresenter::ReleaseBackBufferViews() {
    for (auto* view : m_backBufferViews) {
        if (view != nullptr) {
            view->Shutdown();
            delete view;
        }
    }

    m_backBufferViews.clear();
    m_backBufferSurfaces.clear();
}

bool D3D12WindowSwapChainPresenter::RecreateBackBufferViews() {
    D3D12SwapChain* d3d12SwapChain = GetD3D12SwapChain();
    if (m_hostDevice == nullptr ||
        m_hostDevice->GetRHIDevice() == nullptr ||
        d3d12SwapChain == nullptr) {
        return false;
    }

    m_backBufferViews.resize(kSwapChainBufferCount, nullptr);
    m_backBufferSurfaces.resize(kSwapChainBufferCount);

    ResourceViewDesc viewDesc = {};
    viewDesc.format = static_cast<std::uint32_t>(Format::R8G8B8A8_UNorm);
    viewDesc.dimension = ResourceViewDimension::Texture2D;

    for (std::uint32_t backBufferIndex = 0u;
         backBufferIndex < kSwapChainBufferCount;
         ++backBufferIndex) {
        D3D12Texture* backBufferTexture = d3d12SwapChain->TryGetBackBuffer(backBufferIndex);
        if (backBufferTexture == nullptr) {
            ReleaseBackBufferViews();
            m_lastError = "RecreateBackBufferViews could not resolve swap chain back buffer " +
                std::to_string(backBufferIndex) + ".";
            return false;
        }

        m_backBufferViews[backBufferIndex] = m_hostDevice->GetRHIDevice()->CreateRenderTargetView(
            backBufferTexture,
            viewDesc);
        if (m_backBufferViews[backBufferIndex] == nullptr) {
            ReleaseBackBufferViews();
            m_lastError = "RecreateBackBufferViews failed to create RTV for swap chain back buffer " +
                std::to_string(backBufferIndex) + ".";
            return false;
        }

        ::XCEngine::Rendering::RenderSurface& surface = m_backBufferSurfaces[backBufferIndex];
        surface = ::XCEngine::Rendering::RenderSurface(
            static_cast<std::uint32_t>(m_width),
            static_cast<std::uint32_t>(m_height));
        surface.SetColorAttachment(m_backBufferViews[backBufferIndex]);
        surface.SetAutoTransitionEnabled(false);
        surface.SetColorStateBefore(ResourceStates::RenderTarget);
        surface.SetColorStateAfter(ResourceStates::RenderTarget);
    }

    m_lastError.clear();
    return true;
}

} // namespace XCEngine::UI::Editor::Host