#include <gtest/gtest.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/Debug/ConsoleLogSink.h>
#include <XCEngine/Debug/Logger.h>
#include <XCEngine/Rendering/RenderContext.h>
#include <XCEngine/Rendering/RenderSurface.h>
#include <XCEngine/Rendering/SceneRenderer.h>
#include <XCEngine/Resources/Material/Material.h>
#include <XCEngine/Resources/Mesh/Mesh.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::Debug;
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 = "textured_quad_scene_d3d12.ppm";
constexpr const char* kOpenGLScreenshot = "textured_quad_scene_opengl.ppm";
constexpr uint32_t kFrameWidth = 1280;
constexpr uint32_t kFrameHeight = 720;

Mesh* CreateQuadMesh() {
    auto* mesh = new Mesh();
    IResource::ConstructParams params = {};
    params.name = "TexturedQuad";
    params.path = "Tests/Rendering/TexturedQuad.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, 1, 2, 2, 1, 3 };
    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 = "Checker";
    params.path = "Tests/Rendering/Checker.texture";
    params.guid = ResourceGUID::Generate(params.path);
    texture->Initialize(params);

    const unsigned char pixels[16] = {
        255,  32,  32, 255,
         32, 255,  32, 255,
         32,  32, 255, 255,
        255, 255,  32, 255
    };
    texture->Create(
        2,
        2,
        1,
        1,
        XCEngine::Resources::TextureType::Texture2D,
        XCEngine::Resources::TextureFormat::RGBA8_UNORM,
        pixels,
        sizeof(pixels));
    return texture;
}

Material* CreateMaterial(Texture* texture) {
    auto* material = new Material();
    IResource::ConstructParams params = {};
    params.name = "QuadMaterial";
    params.path = "Tests/Rendering/Quad.material";
    params.guid = ResourceGUID::Generate(params.path);
    material->Initialize(params);
    material->SetTexture("_BaseColorTexture", ResourceHandle<Texture>(texture));
    return material;
}

const char* GetScreenshotFilename(RHIType backendType) {
    return backendType == RHIType::D3D12 ? kD3D12Screenshot : kOpenGLScreenshot;
}

int GetComparisonThreshold(RHIType backendType) {
    return backendType == RHIType::OpenGL ? 5 : 0;
}

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

private:
    RHIResourceView* GetCurrentBackBufferView();

    std::unique_ptr<Scene> mScene;
    std::unique_ptr<SceneRenderer> mSceneRenderer;
    std::vector<RHIResourceView*> mBackBufferViews;
    RHITexture* mDepthTexture = nullptr;
    RHIResourceView* mDepthView = nullptr;
    Mesh* mMesh = nullptr;
    Material* mMaterial = nullptr;
    Texture* mTexture = nullptr;
};

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

    mSceneRenderer = std::make_unique<SceneRenderer>();
    mScene = std::make_unique<Scene>("TexturedQuadScene");

    mMesh = CreateQuadMesh();
    mTexture = CreateCheckerTexture();
    mMaterial = CreateMaterial(mTexture);

    GameObject* cameraObject = mScene->CreateGameObject("MainCamera");
    auto* camera = cameraObject->AddComponent<CameraComponent>();
    camera->SetPrimary(true);
    camera->SetClearColor(XCEngine::Math::Color(0.08f, 0.08f, 0.10f, 1.0f));

    GameObject* quadObject = mScene->CreateGameObject("Quad");
    quadObject->GetTransform()->SetLocalPosition(Vector3(0.0f, 0.0f, 3.0f));
    auto* meshFilter = quadObject->AddComponent<MeshFilterComponent>();
    auto* meshRenderer = quadObject->AddComponent<MeshRendererComponent>();
    meshFilter->SetMesh(ResourceHandle<Mesh>(mMesh));
    meshRenderer->SetMaterial(0, ResourceHandle<Material>(mMaterial));

    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 TexturedQuadSceneTest::TearDown() {
    mSceneRenderer.reset();

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

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

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

    mScene.reset();

    delete mMaterial;
    mMaterial = nullptr;
    delete mMesh;
    mMesh = nullptr;
    delete mTexture;
    mTexture = nullptr;

    RHIIntegrationFixture::TearDown();
}

RHIResourceView* TexturedQuadSceneTest::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 TexturedQuadSceneTest::RenderFrame() {
    ASSERT_NE(mScene, nullptr);
    ASSERT_NE(mSceneRenderer, nullptr);

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

    commandList->Reset();

    RenderSurface surface(kFrameWidth, kFrameHeight);
    surface.SetColorAttachment(GetCurrentBackBufferView());
    surface.SetDepthAttachment(mDepthView);

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

    ASSERT_TRUE(mSceneRenderer->Render(*mScene, nullptr, renderContext, surface));

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

TEST_P(TexturedQuadSceneTest, RenderTexturedQuadScene) {
    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, TexturedQuadSceneTest, ::testing::Values(RHIType::D3D12));
INSTANTIATE_TEST_SUITE_P(OpenGL, TexturedQuadSceneTest, ::testing::Values(RHIType::OpenGL));

GTEST_API_ int main(int argc, char** argv) {
    Logger::Get().Initialize();
    Logger::Get().AddSink(std::make_unique<ConsoleLogSink>());
    Logger::Get().SetMinimumLevel(LogLevel::Debug);

    testing::InitGoogleTest(&argc, argv);
    return RUN_ALL_TESTS();
}