#include <gtest/gtest.h>

#include "../VolumeIntegrationSceneFixture.h"

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

#include <array>
#include <filesystem>
#include <fstream>
#include <iomanip>
#include <sstream>
#include <string>
#include <vector>

using namespace VolumeIntegrationTestUtils;

namespace {

constexpr int kWarmupFrames = 20;
constexpr int kMeasuredFrames = 60;

struct QualityProfile {
    const char* name = "";
    float stepSize = 1.0f;
    float maxSteps = 2000.0f;
    const char* screenshotFilename = "";
};

struct OptimizationProfile {
    const char* name = "";
    float enableEntryHdda = 1.0f;
    float enableEmptySpaceSkipping = 1.0f;
    float enableEarlyTermination = 1.0f;
    const char* screenshotFilename = "";
};

struct QualityResult {
    std::string name;
    float stepSize = 0.0f;
    float maxSteps = 0.0f;
    StableFrameStats stats = {};
    std::string screenshotFilename;
};

struct OptimizationResult {
    std::string name;
    float enableEntryHdda = 1.0f;
    float enableEmptySpaceSkipping = 1.0f;
    float enableEarlyTermination = 1.0f;
    StableFrameStats stats = {};
    std::string screenshotFilename;
};

std::string FormatNumber(double value, int precision = 3) {
    std::ostringstream stream;
    stream << std::fixed << std::setprecision(precision) << value;
    return stream.str();
}

void WriteQualityResults(const std::vector<QualityResult>& results) {
    const std::filesystem::path tsvPath =
        RenderingIntegrationTestUtils::ResolveRuntimePath("volume_quality_results.tsv");
    std::ofstream tsv(tsvPath, std::ios::trunc);
    ASSERT_TRUE(tsv.is_open()) << tsvPath.string();
    tsv << "profile\tstep_size\tmax_steps\twarmup_frames\tmeasured_frames\tavg_frame_ms\tmin_frame_ms\tmax_frame_ms\tavg_fps\tscreenshot\n";
    for (const QualityResult& result : results) {
        tsv << result.name << '\t'
            << result.stepSize << '\t'
            << result.maxSteps << '\t'
            << result.stats.warmupFrames << '\t'
            << result.stats.measuredFrames << '\t'
            << FormatNumber(result.stats.averageFrameTimeMs) << '\t'
            << FormatNumber(result.stats.minFrameTimeMs) << '\t'
            << FormatNumber(result.stats.maxFrameTimeMs) << '\t'
            << FormatNumber(result.stats.averageFps) << '\t'
            << result.screenshotFilename << '\n';
    }

    const std::filesystem::path markdownPath =
        RenderingIntegrationTestUtils::ResolveRuntimePath("volume_quality_results.md");
    std::ofstream markdown(markdownPath, std::ios::trunc);
    ASSERT_TRUE(markdown.is_open()) << markdownPath.string();
    markdown << "|profile|StepSize|MaxSteps|warmup_frames|measured_frames|avg_frame_ms|min_frame_ms|max_frame_ms|avg_fps|screenshot|\n";
    markdown << "|---|---:|---:|---:|---:|---:|---:|---:|---:|---|\n";
    for (const QualityResult& result : results) {
        markdown << '|'
                 << result.name << '|'
                 << result.stepSize << '|'
                 << result.maxSteps << '|'
                 << result.stats.warmupFrames << '|'
                 << result.stats.measuredFrames << '|'
                 << FormatNumber(result.stats.averageFrameTimeMs) << '|'
                 << FormatNumber(result.stats.minFrameTimeMs) << '|'
                 << FormatNumber(result.stats.maxFrameTimeMs) << '|'
                 << FormatNumber(result.stats.averageFps) << '|'
                 << result.screenshotFilename << "|\n";
    }
}

void WriteOptimizationResults(const std::vector<OptimizationResult>& results) {
    const std::filesystem::path tsvPath =
        RenderingIntegrationTestUtils::ResolveRuntimePath("volume_optimization_results.tsv");
    std::ofstream tsv(tsvPath, std::ios::trunc);
    ASSERT_TRUE(tsv.is_open()) << tsvPath.string();
    tsv << "profile\tenable_entry_hdda\tenable_empty_space_skipping\tenable_early_termination\twarmup_frames\tmeasured_frames\tavg_frame_ms\tmin_frame_ms\tmax_frame_ms\tavg_fps\tscreenshot\n";
    for (const OptimizationResult& result : results) {
        tsv << result.name << '\t'
            << result.enableEntryHdda << '\t'
            << result.enableEmptySpaceSkipping << '\t'
            << result.enableEarlyTermination << '\t'
            << result.stats.warmupFrames << '\t'
            << result.stats.measuredFrames << '\t'
            << FormatNumber(result.stats.averageFrameTimeMs) << '\t'
            << FormatNumber(result.stats.minFrameTimeMs) << '\t'
            << FormatNumber(result.stats.maxFrameTimeMs) << '\t'
            << FormatNumber(result.stats.averageFps) << '\t'
            << result.screenshotFilename << '\n';
    }

    const std::filesystem::path markdownPath =
        RenderingIntegrationTestUtils::ResolveRuntimePath("volume_optimization_results.md");
    std::ofstream markdown(markdownPath, std::ios::trunc);
    ASSERT_TRUE(markdown.is_open()) << markdownPath.string();
    markdown << "|profile|enable_entry_hdda|enable_empty_space_skipping|enable_early_termination|warmup_frames|measured_frames|avg_frame_ms|min_frame_ms|max_frame_ms|avg_fps|screenshot|\n";
    markdown << "|---|---:|---:|---:|---:|---:|---:|---:|---:|---:|---|\n";
    for (const OptimizationResult& result : results) {
        markdown << '|'
                 << result.name << '|'
                 << result.enableEntryHdda << '|'
                 << result.enableEmptySpaceSkipping << '|'
                 << result.enableEarlyTermination << '|'
                 << result.stats.warmupFrames << '|'
                 << result.stats.measuredFrames << '|'
                 << FormatNumber(result.stats.averageFrameTimeMs) << '|'
                 << FormatNumber(result.stats.minFrameTimeMs) << '|'
                 << FormatNumber(result.stats.maxFrameTimeMs) << '|'
                 << FormatNumber(result.stats.averageFps) << '|'
                 << result.screenshotFilename << "|\n";
    }
}

class VolumePerformanceSuiteTest : public VolumeIntegrationSceneFixture {
protected:
    const char* GetSceneName() const override { return "VolumePerformanceSuite"; }
    void BuildScene() override;
    void ReleaseSceneResources() override;

    void ApplyQualityProfile(const QualityProfile& profile);
    void ApplyOptimizationProfile(const OptimizationProfile& profile);

private:
    Material* mVolumeMaterial = nullptr;
    VolumeField* mVolumeField = nullptr;
};

void VolumePerformanceSuiteTest::BuildScene() {
    mVolumeMaterial = CreateVolumetricMaterial(
        "VolumePerformanceMaterial",
        "Tests/Rendering/VolumePerformanceSuite/Volume.material",
        Vector4(1.0f, 1.0f, 1.0f, 1.0f),
        0.2f,
        1.0f,
        2000.0f,
        0.005f,
        Vector3(-0.72f, 0.16f, 0.67f),
        8.0f,
        1.0f,
        1.0f,
        1.0f);
    ASSERT_NE(mVolumeMaterial, nullptr);

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

    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(-10.0f, 300.0f, -1200.0f));
    cameraObject->GetTransform()->LookAt(Vector3(-10.0f, 73.0f, 0.0f));

    GameObject* lightObject = mScene->CreateGameObject("MainDirectionalLight");
    auto* light = lightObject->AddComponent<LightComponent>();
    light->SetLightType(LightType::Directional);
    light->SetColor(XCEngine::Math::Color(1.0f, 1.0f, 1.0f, 1.0f));
    light->SetIntensity(1.0f);
    lightObject->GetTransform()->LookAt(Vector3(-0.5f, -0.8f, -0.3f));

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

    RenderSceneExtractor extractor;
    const RenderSceneData sceneData = extractor.Extract(*mScene, nullptr, kFrameWidth, kFrameHeight);
    ASSERT_EQ(sceneData.visibleItems.size(), 0u);
    ASSERT_EQ(sceneData.visibleVolumes.size(), 1u);
    ASSERT_TRUE(sceneData.lighting.HasMainDirectionalLight());
}

void VolumePerformanceSuiteTest::ReleaseSceneResources() {
    delete mVolumeField;
    mVolumeField = nullptr;
    delete mVolumeMaterial;
    mVolumeMaterial = nullptr;
}

void VolumePerformanceSuiteTest::ApplyQualityProfile(const QualityProfile& profile) {
    ASSERT_NE(mVolumeMaterial, nullptr);
    mVolumeMaterial->SetFloat("_StepSize", profile.stepSize);
    mVolumeMaterial->SetFloat("_MaxSteps", profile.maxSteps);
    mVolumeMaterial->SetFloat("_LightSamples", 8.0f);
    mVolumeMaterial->SetFloat("_EnableEntryHdda", 1.0f);
    mVolumeMaterial->SetFloat("_EnableEmptySpaceSkipping", 1.0f);
    mVolumeMaterial->SetFloat("_EnableEarlyTermination", 1.0f);
}

void VolumePerformanceSuiteTest::ApplyOptimizationProfile(const OptimizationProfile& profile) {
    ASSERT_NE(mVolumeMaterial, nullptr);
    mVolumeMaterial->SetFloat("_StepSize", 1.0f);
    mVolumeMaterial->SetFloat("_MaxSteps", 2000.0f);
    mVolumeMaterial->SetFloat("_LightSamples", 8.0f);
    mVolumeMaterial->SetFloat("_EnableEntryHdda", profile.enableEntryHdda);
    mVolumeMaterial->SetFloat("_EnableEmptySpaceSkipping", profile.enableEmptySpaceSkipping);
    mVolumeMaterial->SetFloat("_EnableEarlyTermination", profile.enableEarlyTermination);
}

TEST_P(VolumePerformanceSuiteTest, MeasureQualityProfiles) {
    const std::array<QualityProfile, 3> profiles = {
        QualityProfile{ "high_quality", 0.25f, 8000.0f, "volume_quality_high_d3d12.ppm" },
        QualityProfile{ "balanced", 1.0f, 2000.0f, "volume_quality_balanced_d3d12.ppm" },
        QualityProfile{ "high_performance", 4.0f, 512.0f, "volume_quality_performance_d3d12.ppm" }
    };

    std::vector<QualityResult> results;
    results.reserve(profiles.size());
    for (const QualityProfile& profile : profiles) {
        ApplyQualityProfile(profile);
        const StableFrameStats stats = RenderAndMeasureStableFrames(
            kWarmupFrames,
            kMeasuredFrames,
            profile.screenshotFilename);
        EXPECT_GT(stats.averageFrameTimeMs, 0.0);
        EXPECT_GT(stats.averageFps, 0.0);

        const RenderingIntegrationTestUtils::PpmImage image =
            RenderingIntegrationTestUtils::LoadPpmImage(profile.screenshotFilename);
        EXPECT_EQ(image.width, kFrameWidth);
        EXPECT_EQ(image.height, kFrameHeight);

        results.push_back(QualityResult{
            profile.name,
            profile.stepSize,
            profile.maxSteps,
            stats,
            profile.screenshotFilename
        });
    }

    WriteQualityResults(results);
}

TEST_P(VolumePerformanceSuiteTest, MeasureOptimizationVariants) {
    const std::array<OptimizationProfile, 4> profiles = {
        OptimizationProfile{ "full_optimization", 1.0f, 1.0f, 1.0f, "volume_opt_full_d3d12.ppm" },
        OptimizationProfile{ "disable_entry_hdda", 0.0f, 1.0f, 1.0f, "volume_opt_no_entry_hdda_d3d12.ppm" },
        OptimizationProfile{ "disable_empty_space_skipping", 1.0f, 0.0f, 1.0f, "volume_opt_no_empty_space_skip_d3d12.ppm" },
        OptimizationProfile{ "disable_early_termination", 1.0f, 1.0f, 0.0f, "volume_opt_no_early_termination_d3d12.ppm" }
    };

    std::vector<OptimizationResult> results;
    results.reserve(profiles.size());
    for (const OptimizationProfile& profile : profiles) {
        ApplyOptimizationProfile(profile);
        const StableFrameStats stats = RenderAndMeasureStableFrames(
            kWarmupFrames,
            kMeasuredFrames,
            profile.screenshotFilename);
        EXPECT_GT(stats.averageFrameTimeMs, 0.0);
        EXPECT_GT(stats.averageFps, 0.0);

        const RenderingIntegrationTestUtils::PpmImage image =
            RenderingIntegrationTestUtils::LoadPpmImage(profile.screenshotFilename);
        EXPECT_EQ(image.width, kFrameWidth);
        EXPECT_EQ(image.height, kFrameHeight);

        results.push_back(OptimizationResult{
            profile.name,
            profile.enableEntryHdda,
            profile.enableEmptySpaceSkipping,
            profile.enableEarlyTermination,
            stats,
            profile.screenshotFilename
        });
    }

    WriteOptimizationResults(results);
}

} // namespace

INSTANTIATE_TEST_SUITE_P(D3D12, VolumePerformanceSuiteTest, ::testing::Values(XCEngine::RHI::RHIType::D3D12));

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