#include <gtest/gtest.h>

#include "../VolumeIntegrationSceneFixture.h"

#include <XCEngine/Components/CameraComponent.h>
#include <XCEngine/Components/GameObject.h>
#include <XCEngine/Components/MeshFilterComponent.h>
#include <XCEngine/Components/MeshRendererComponent.h>
#include <XCEngine/Components/VolumeRendererComponent.h>
#include <XCEngine/Core/Math/Vector3.h>
#include <XCEngine/Rendering/Extraction/RenderSceneExtractor.h>

using namespace VolumeIntegrationTestUtils;

namespace {

constexpr const char* kD3D12Screenshot = "volume_occlusion_scene_d3d12.ppm";
constexpr const char* kOpenGLScreenshot = "volume_occlusion_scene_opengl.ppm";
constexpr const char* kVulkanScreenshot = "volume_occlusion_scene_vulkan.ppm";

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

class VolumeOcclusionSceneTest : public VolumeIntegrationSceneFixture {
protected:
    const char* GetSceneName() const override { return "VolumeOcclusionScene"; }

    void BuildScene() override {
        mVolumeMaterial = CreateVolumetricMaterial(
            "VolumeOcclusionMaterial",
            "Tests/Rendering/VolumeOcclusionScene/Volume.material",
            Vector4(1.0f, 1.0f, 1.0f, 1.0f),
            0.24f,
            0.75f,
            2400.0f,
            0.003f,
            Vector3(0.42f, 0.86f, 0.29f),
            10.0f);
        ASSERT_NE(mVolumeMaterial, nullptr);

        mOccluderMaterial = CreateUnlitMaterial(
            "VolumeOccluderMaterial",
            "Tests/Rendering/VolumeOcclusionScene/Occluder.material",
            Vector4(0.92f, 0.36f, 0.18f, 1.0f));
        ASSERT_NE(mOccluderMaterial, nullptr);

        mVolumeField = LoadCloudVolumeField();
        ASSERT_NE(mVolumeField, nullptr);

        mCubeMesh = LoadBuiltinPrimitiveMesh(BuiltinPrimitiveType::Cube);
        ASSERT_TRUE(mCubeMesh.IsValid());

        GameObject* cameraObject = mScene->CreateGameObject("MainCamera");
        auto* camera = cameraObject->AddComponent<CameraComponent>();
        camera->SetPrimary(true);
        camera->SetFieldOfView(45.0f);
        camera->SetNearClipPlane(0.1f);
        camera->SetFarClipPlane(5000.0f);
        camera->SetClearColor(XCEngine::Math::Color(0.03f, 0.04f, 0.06f, 1.0f));
        cameraObject->GetTransform()->SetLocalPosition(Vector3(220.0f, 300.0f, -1200.0f));
        cameraObject->GetTransform()->LookAt(Vector3(220.0f, 73.0f, 0.0f));

        GameObject* volumeObject = mScene->CreateGameObject("CloudVolume");
        auto* volumeRenderer = volumeObject->AddComponent<VolumeRendererComponent>();
        volumeRenderer->SetVolumeField(mVolumeField);
        volumeRenderer->SetMaterial(mVolumeMaterial);
        volumeRenderer->SetCastShadows(false);
        volumeRenderer->SetReceiveShadows(false);

        GameObject* occluderObject = mScene->CreateGameObject("Occluder");
        occluderObject->GetTransform()->SetLocalPosition(Vector3(220.0f, 88.0f, -900.0f));
        occluderObject->GetTransform()->SetLocalScale(Vector3(450.0f, 320.0f, 12.0f));
        auto* meshFilter = occluderObject->AddComponent<MeshFilterComponent>();
        auto* meshRenderer = occluderObject->AddComponent<MeshRendererComponent>();
        meshFilter->SetMesh(mCubeMesh);
        meshRenderer->SetMaterial(0, mOccluderMaterial);
        meshRenderer->SetCastShadows(false);
        meshRenderer->SetReceiveShadows(false);

        RenderSceneExtractor extractor;
        const RenderSceneData sceneData = extractor.Extract(*mScene, nullptr, kFrameWidth, kFrameHeight);
        ASSERT_EQ(sceneData.visibleItems.size(), 1u);
        ASSERT_EQ(sceneData.visibleVolumes.size(), 1u);
    }

    void ReleaseSceneResources() override {
        delete mVolumeField;
        mVolumeField = nullptr;
        delete mVolumeMaterial;
        mVolumeMaterial = nullptr;
        delete mOccluderMaterial;
        mOccluderMaterial = nullptr;
        mCubeMesh.Reset();
    }

private:
    Material* mVolumeMaterial = nullptr;
    Material* mOccluderMaterial = nullptr;
    VolumeField* mVolumeField = nullptr;
    ResourceHandle<Mesh> mCubeMesh;
};

TEST_P(VolumeOcclusionSceneTest, RenderNanoVdbVolumeOcclusionScene) {
    const char* screenshotFilename = GetScreenshotFilename(GetBackendType());
    RenderAndCompare(screenshotFilename, 0.0f);

    const RenderingIntegrationTestUtils::PpmImage image =
        RenderingIntegrationTestUtils::LoadPpmImage(screenshotFilename);
    RenderingIntegrationTestUtils::ExpectPixelLuminanceAtMost(
        image,
        640u,
        360u,
        520,
        "occluder center should stay opaque");
    RenderingIntegrationTestUtils::ExpectPixelLuminanceAtLeast(
        image,
        1060u,
        360u,
        150,
        "cloud edge should remain visible");
}

} // namespace

INSTANTIATE_TEST_SUITE_P(D3D12, VolumeOcclusionSceneTest, ::testing::Values(XCEngine::RHI::RHIType::D3D12));
#if defined(XCENGINE_SUPPORT_OPENGL)
INSTANTIATE_TEST_SUITE_P(OpenGL, VolumeOcclusionSceneTest, ::testing::Values(XCEngine::RHI::RHIType::OpenGL));
#endif
#if defined(XCENGINE_SUPPORT_VULKAN)
INSTANTIATE_TEST_SUITE_P(Vulkan, VolumeOcclusionSceneTest, ::testing::Values(XCEngine::RHI::RHIType::Vulkan));
#endif

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