#include <gtest/gtest.h>

#include "../RenderingIntegrationMain.h"

#include <XCEngine/Components/CameraComponent.h>
#include <XCEngine/Components/GameObject.h>
#include <XCEngine/Components/MeshFilterComponent.h>
#include <XCEngine/Components/MeshRendererComponent.h>
#include <XCEngine/Core/Asset/IResource.h>
#include <XCEngine/Core/Math/Color.h>
#include <XCEngine/Core/Math/Vector2.h>
#include <XCEngine/Core/Math/Vector3.h>
#include <XCEngine/Rendering/Execution/CameraRenderer.h>
#include <XCEngine/Rendering/Passes/BuiltinColorScalePostProcessPass.h>
#include <XCEngine/Rendering/RenderContext.h>
#include <XCEngine/Rendering/RenderSurface.h>
#include <XCEngine/Resources/BuiltinResources.h>
#include <XCEngine/Resources/Material/Material.h>
#include <XCEngine/Resources/Mesh/Mesh.h>
#include <XCEngine/Resources/Shader/Shader.h>
#include <XCEngine/Resources/Texture/Texture.h>
#include <XCEngine/RHI/RHITexture.h>
#include <XCEngine/Scene/Scene.h>
#include "../../../RHI/integration/fixtures/RHIIntegrationFixture.h"

#include <memory>
#include <vector>

using namespace XCEngine::Components;
using namespace XCEngine::Math;
using namespace XCEngine::Rendering;
using namespace XCEngine::Resources;
using namespace XCEngine::RHI;
using namespace XCEngine::RHI::Integration;

namespace {

constexpr const char* kD3D12Screenshot = "post_process_scene_d3d12.ppm";
constexpr const char* kOpenGLScreenshot = "post_process_scene_opengl.ppm";
constexpr const char* kVulkanScreenshot = "post_process_scene_vulkan.ppm";
constexpr uint32_t kFrameWidth = 1280;
constexpr uint32_t kFrameHeight = 720;

Mesh* CreateQuadMesh() {
    auto* mesh = new Mesh();
    IResource::ConstructParams params = {};
    params.name = "PostProcessQuad";
    params.path = "Tests/Rendering/PostProcessQuad.mesh";
    params.guid = ResourceGUID::Generate(params.path);
    mesh->Initialize(params);

    StaticMeshVertex vertices[4] = {};
    vertices[0].position = Vector3(-1.0f, -1.0f, 0.0f);
    vertices[0].uv0 = Vector2(0.0f, 1.0f);
    vertices[1].position = Vector3(-1.0f, 1.0f, 0.0f);
    vertices[1].uv0 = Vector2(0.0f, 0.0f);
    vertices[2].position = Vector3(1.0f, -1.0f, 0.0f);
    vertices[2].uv0 = Vector2(1.0f, 1.0f);
    vertices[3].position = Vector3(1.0f, 1.0f, 0.0f);
    vertices[3].uv0 = Vector2(1.0f, 0.0f);

    const uint32_t indices[6] = { 0, 2, 1, 2, 3, 1 };
    mesh->SetVertexData(
        vertices,
        sizeof(vertices),
        4,
        sizeof(StaticMeshVertex),
        VertexAttribute::Position | VertexAttribute::UV0);
    mesh->SetIndexData(indices, sizeof(indices), 6, true);

    MeshSection section = {};
    section.baseVertex = 0;
    section.vertexCount = 4;
    section.startIndex = 0;
    section.indexCount = 6;
    section.materialID = 0;
    mesh->AddSection(section);
    return mesh;
}

Texture* CreateCheckerTexture() {
    auto* texture = new Texture();
    IResource::ConstructParams params = {};
    params.name = "PostProcessChecker";
    params.path = "Tests/Rendering/PostProcessChecker.texture";
    params.guid = ResourceGUID::Generate(params.path);
    texture->Initialize(params);

    const unsigned char pixels[16] = {
        255,  96,  64, 255,
         64, 255,  96, 255,
         48,  96, 255, 255,
        255, 240,  96, 255
    };
    texture->Create(
        2,
        2,
        1,
        1,
        XCEngine::Resources::TextureType::Texture2D,
        XCEngine::Resources::TextureFormat::RGBA8_UNORM,
        pixels,
        sizeof(pixels));
    return texture;
}

Material* CreateQuadMaterial(Texture* texture) {
    auto* material = new Material();
    IResource::ConstructParams params = {};
    params.name = "PostProcessQuadMaterial";
    params.path = "Tests/Rendering/PostProcessQuad.material";
    params.guid = ResourceGUID::Generate(params.path);
    material->Initialize(params);
    material->SetShader(ResourceManager::Get().Load<Shader>(GetBuiltinUnlitShaderPath()));
    material->SetTexture("_MainTex", ResourceHandle<Texture>(texture));
    return material;
}

const char* GetScreenshotFilename(RHIType backendType) {
    switch (backendType) {
        case RHIType::D3D12:
            return kD3D12Screenshot;
        case RHIType::Vulkan:
            return kVulkanScreenshot;
        case RHIType::OpenGL:
        default:
            return kOpenGLScreenshot;
    }
}

int GetComparisonThreshold(RHIType backendType) {
    return backendType == RHIType::D3D12 ? 0 : 6;
}

class PostProcessSceneTest : public RHIIntegrationFixture {
protected:
    void SetUp() override;
    void TearDown() override;
    void RenderFrame() override;

private:
    void BuildScene();
    RHIResourceView* GetCurrentBackBufferView();

    std::unique_ptr<Scene> mScene;
    std::unique_ptr<CameraRenderer> mCameraRenderer;
    RenderPassSequence mPostProcessPasses;
    std::vector<RHIResourceView*> mBackBufferViews;
    RHITexture* mSceneColorTexture = nullptr;
    RHIResourceView* mSceneColorTargetView = nullptr;
    RHIResourceView* mSceneColorShaderView = nullptr;
    RHITexture* mDepthTexture = nullptr;
    RHIResourceView* mDepthView = nullptr;
    Mesh* mMesh = nullptr;
    Material* mMaterial = nullptr;
    Texture* mTexture = nullptr;
    CameraComponent* mCamera = nullptr;
};

void PostProcessSceneTest::SetUp() {
    RHIIntegrationFixture::SetUp();

    mCameraRenderer = std::make_unique<CameraRenderer>();
    mScene = std::make_unique<Scene>("PostProcessScene");
    mMesh = CreateQuadMesh();
    mTexture = CreateCheckerTexture();
    mMaterial = CreateQuadMaterial(mTexture);
    mPostProcessPasses.AddPass(std::make_unique<Passes::BuiltinColorScalePostProcessPass>(
        Vector4(1.0f, 0.75f, 0.75f, 1.0f)));
    mPostProcessPasses.AddPass(std::make_unique<Passes::BuiltinColorScalePostProcessPass>(
        Vector4(0.55f, 0.95f, 1.0f, 1.0f)));

    BuildScene();

    TextureDesc sceneColorDesc = {};
    sceneColorDesc.width = kFrameWidth;
    sceneColorDesc.height = kFrameHeight;
    sceneColorDesc.depth = 1;
    sceneColorDesc.mipLevels = 1;
    sceneColorDesc.arraySize = 1;
    sceneColorDesc.format = static_cast<uint32_t>(Format::R8G8B8A8_UNorm);
    sceneColorDesc.textureType = static_cast<uint32_t>(XCEngine::RHI::TextureType::Texture2D);
    sceneColorDesc.sampleCount = 1;
    sceneColorDesc.sampleQuality = 0;
    sceneColorDesc.flags = 0;
    mSceneColorTexture = GetDevice()->CreateTexture(sceneColorDesc);
    ASSERT_NE(mSceneColorTexture, nullptr);

    ResourceViewDesc sceneColorViewDesc = {};
    sceneColorViewDesc.format = static_cast<uint32_t>(Format::R8G8B8A8_UNorm);
    sceneColorViewDesc.dimension = ResourceViewDimension::Texture2D;
    sceneColorViewDesc.mipLevel = 0;
    mSceneColorTargetView = GetDevice()->CreateRenderTargetView(mSceneColorTexture, sceneColorViewDesc);
    ASSERT_NE(mSceneColorTargetView, nullptr);
    mSceneColorShaderView = GetDevice()->CreateShaderResourceView(mSceneColorTexture, sceneColorViewDesc);
    ASSERT_NE(mSceneColorShaderView, nullptr);

    TextureDesc depthDesc = {};
    depthDesc.width = kFrameWidth;
    depthDesc.height = kFrameHeight;
    depthDesc.depth = 1;
    depthDesc.mipLevels = 1;
    depthDesc.arraySize = 1;
    depthDesc.format = static_cast<uint32_t>(Format::D24_UNorm_S8_UInt);
    depthDesc.textureType = static_cast<uint32_t>(XCEngine::RHI::TextureType::Texture2D);
    depthDesc.sampleCount = 1;
    depthDesc.sampleQuality = 0;
    depthDesc.flags = 0;
    mDepthTexture = GetDevice()->CreateTexture(depthDesc);
    ASSERT_NE(mDepthTexture, nullptr);

    ResourceViewDesc depthViewDesc = {};
    depthViewDesc.format = static_cast<uint32_t>(Format::D24_UNorm_S8_UInt);
    depthViewDesc.dimension = ResourceViewDimension::Texture2D;
    depthViewDesc.mipLevel = 0;
    mDepthView = GetDevice()->CreateDepthStencilView(mDepthTexture, depthViewDesc);
    ASSERT_NE(mDepthView, nullptr);

    mBackBufferViews.resize(2, nullptr);
}

void PostProcessSceneTest::TearDown() {
    if (GetCommandQueue() != nullptr) {
        GetCommandQueue()->WaitForIdle();
    }
    mPostProcessPasses.Shutdown();
    mCameraRenderer.reset();

    if (mDepthView != nullptr) {
        mDepthView->Shutdown();
        delete mDepthView;
        mDepthView = nullptr;
    }

    if (mDepthTexture != nullptr) {
        mDepthTexture->Shutdown();
        delete mDepthTexture;
        mDepthTexture = nullptr;
    }

    if (mSceneColorShaderView != nullptr) {
        mSceneColorShaderView->Shutdown();
        delete mSceneColorShaderView;
        mSceneColorShaderView = nullptr;
    }

    if (mSceneColorTargetView != nullptr) {
        mSceneColorTargetView->Shutdown();
        delete mSceneColorTargetView;
        mSceneColorTargetView = nullptr;
    }

    if (mSceneColorTexture != nullptr) {
        mSceneColorTexture->Shutdown();
        delete mSceneColorTexture;
        mSceneColorTexture = nullptr;
    }

    for (RHIResourceView*& backBufferView : mBackBufferViews) {
        if (backBufferView != nullptr) {
            backBufferView->Shutdown();
            delete backBufferView;
            backBufferView = nullptr;
        }
    }
    mBackBufferViews.clear();

    mScene.reset();

    delete mMaterial;
    mMaterial = nullptr;

    delete mTexture;
    mTexture = nullptr;

    delete mMesh;
    mMesh = nullptr;

    mCamera = nullptr;

    RHIIntegrationFixture::TearDown();
}

void PostProcessSceneTest::BuildScene() {
    ASSERT_NE(mScene, nullptr);

    GameObject* cameraObject = mScene->CreateGameObject("MainCamera");
    mCamera = cameraObject->AddComponent<CameraComponent>();
    ASSERT_NE(mCamera, nullptr);
    mCamera->SetPrimary(true);
    mCamera->SetFieldOfView(50.0f);
    mCamera->SetNearClipPlane(0.1f);
    mCamera->SetFarClipPlane(20.0f);
    mCamera->SetClearColor(XCEngine::Math::Color(0.06f, 0.08f, 0.12f, 1.0f));

    GameObject* quadObject = mScene->CreateGameObject("Quad");
    quadObject->GetTransform()->SetLocalPosition(Vector3(0.0f, 0.0f, 3.0f));
    quadObject->GetTransform()->SetLocalScale(Vector3(1.6f, 1.6f, 1.0f));

    auto* meshFilter = quadObject->AddComponent<MeshFilterComponent>();
    auto* meshRenderer = quadObject->AddComponent<MeshRendererComponent>();
    meshFilter->SetMesh(ResourceHandle<Mesh>(mMesh));
    meshRenderer->SetMaterial(0, ResourceHandle<Material>(mMaterial));
}

RHIResourceView* PostProcessSceneTest::GetCurrentBackBufferView() {
    const int backBufferIndex = GetCurrentBackBufferIndex();
    if (backBufferIndex < 0) {
        return nullptr;
    }

    if (static_cast<size_t>(backBufferIndex) >= mBackBufferViews.size()) {
        mBackBufferViews.resize(static_cast<size_t>(backBufferIndex) + 1, nullptr);
    }

    if (mBackBufferViews[backBufferIndex] == nullptr) {
        ResourceViewDesc viewDesc = {};
        viewDesc.format = static_cast<uint32_t>(Format::R8G8B8A8_UNorm);
        viewDesc.dimension = ResourceViewDimension::Texture2D;
        viewDesc.mipLevel = 0;
        mBackBufferViews[backBufferIndex] = GetDevice()->CreateRenderTargetView(GetCurrentBackBuffer(), viewDesc);
    }

    return mBackBufferViews[backBufferIndex];
}

void PostProcessSceneTest::RenderFrame() {
    ASSERT_NE(mScene, nullptr);
    ASSERT_NE(mCameraRenderer, nullptr);
    ASSERT_NE(mCamera, nullptr);
    ASSERT_NE(mSceneColorTargetView, nullptr);
    ASSERT_NE(mSceneColorShaderView, nullptr);
    ASSERT_NE(mDepthView, nullptr);

    RHICommandList* commandList = GetCommandList();
    ASSERT_NE(commandList, nullptr);

    RHIResourceView* backBufferView = GetCurrentBackBufferView();
    ASSERT_NE(backBufferView, nullptr);

    commandList->Reset();

    RenderSurface mainSceneSurface(kFrameWidth, kFrameHeight);
    mainSceneSurface.SetColorAttachment(mSceneColorTargetView);
    mainSceneSurface.SetDepthAttachment(mDepthView);
    mainSceneSurface.SetColorStateBefore(ResourceStates::Common);
    mainSceneSurface.SetColorStateAfter(ResourceStates::PixelShaderResource);

    RenderSurface finalSurface(kFrameWidth, kFrameHeight);
    finalSurface.SetColorAttachment(backBufferView);
    finalSurface.SetColorStateBefore(ResourceStates::Present);
    finalSurface.SetColorStateAfter(ResourceStates::Present);

    RenderContext renderContext = {};
    renderContext.device = GetDevice();
    renderContext.commandList = commandList;
    renderContext.commandQueue = GetCommandQueue();
    renderContext.backendType = GetBackendType();

    CameraRenderRequest request = {};
    request.scene = mScene.get();
    request.camera = mCamera;
    request.context = renderContext;
    request.surface = finalSurface;
    request.postProcess.sourceSurface = mainSceneSurface;
    request.postProcess.sourceColorView = mSceneColorShaderView;
    request.postProcess.destinationSurface = finalSurface;
    request.postProcess.passes = &mPostProcessPasses;

    ASSERT_TRUE(mCameraRenderer->Render(request));

    commandList->Close();
    void* commandLists[] = { commandList };
    GetCommandQueue()->ExecuteCommandLists(1, commandLists);
}

TEST_P(PostProcessSceneTest, RenderPostProcessScene) {
    RHICommandQueue* commandQueue = GetCommandQueue();
    RHISwapChain* swapChain = GetSwapChain();
    const int targetFrameCount = 30;
    const char* screenshotFilename = GetScreenshotFilename(GetBackendType());
    const int comparisonThreshold = GetComparisonThreshold(GetBackendType());

    for (int frameCount = 0; frameCount <= targetFrameCount; ++frameCount) {
        if (frameCount > 0) {
            commandQueue->WaitForPreviousFrame();
        }

        BeginRender();
        RenderFrame();

        if (frameCount >= targetFrameCount) {
            commandQueue->WaitForIdle();
            ASSERT_TRUE(TakeScreenshot(screenshotFilename));
            ASSERT_TRUE(CompareWithGoldenTemplate(
                screenshotFilename,
                "GT.ppm",
                static_cast<float>(comparisonThreshold)));
            break;
        }

        swapChain->Present(0, 0);
    }
}

} // namespace

INSTANTIATE_TEST_SUITE_P(D3D12, PostProcessSceneTest, ::testing::Values(RHIType::D3D12));
INSTANTIATE_TEST_SUITE_P(OpenGL, PostProcessSceneTest, ::testing::Values(RHIType::OpenGL));
#if defined(XCENGINE_SUPPORT_VULKAN)
INSTANTIATE_TEST_SUITE_P(Vulkan, PostProcessSceneTest, ::testing::Values(RHIType::Vulkan));
#endif

GTEST_API_ int main(int argc, char** argv) {
    return RunRenderingIntegrationTestMain(argc, argv);
}