/// @file bench_io_perf.cpp
/// @brief 导入/导出性能基准测试
///
/// 测试 IGES/STEP 格式的导出耗时和导入耗时。

#include <gtest/gtest.h>
#include "vde/brep/brep.h"
#include "vde/brep/modeling.h"
#include "vde/brep/iges_export.h"
#include "vde/brep/iges_import.h"
#include "vde/brep/step_export.h"
#include "vde/brep/step_import.h"
#include <chrono>
#include <iostream>
#include <iomanip>
#include <vector>

using namespace vde::brep;
using namespace std::chrono;

struct IOBenchmarkResult {
    std::string name;
    double time_ms;
    size_t data_size_bytes;
};

static std::vector<IOBenchmarkResult> g_io_results;

static double measure_ms(std::function<void()> fn, int iterations = 3) {
    double best = 1e18;
    for (int i = 0; i < iterations; ++i) {
        auto start = high_resolution_clock::now();
        fn();
        auto end = high_resolution_clock::now();
        double ms = duration_cast<microseconds>(end - start).count() / 1000.0;
        if (ms < best) best = ms;
    }
    return best;
}

static void record_io(const std::string& name, double ms, size_t bytes) {
    g_io_results.push_back({name, ms, bytes});
    std::cout << "  [BENCH] " << std::left << std::setw(40) << name
              << std::right << std::setw(10) << std::fixed << std::setprecision(2)
              << ms << " ms"
              << "  (data=" << bytes << " bytes)"
              << std::endl;
}

// ═══════════════════════════════════════════════
//  IGES 基准
// ═══════════════════════════════════════════════

TEST(BenchmarkIO, IGES_Export_SingleBody) {
    auto body = make_box(10.0, 5.0, 3.0);

    std::string result;
    double ms = measure_ms([&]() {
        result = export_iges({body});
    }, 5);

    EXPECT_FALSE(result.empty());
    record_io("IO.IGES.Export/SingleBox", ms, result.size());
}

TEST(BenchmarkIO, IGES_Export_Sphere) {
    auto body = make_sphere(5.0, 16, 8);

    std::string result;
    double ms = measure_ms([&]() {
        result = export_iges({body});
    }, 5);

    EXPECT_FALSE(result.empty());
    record_io("IO.IGES.Export/Sphere16x8", ms, result.size());
}

TEST(BenchmarkIO, IGES_RoundTrip_Box) {
    auto body = make_box(10.0, 5.0, 3.0);

    // Export
    std::string iges = export_iges({body});

    // Import benchmark
    double ms = measure_ms([&]() {
        auto loaded = import_iges_from_string(iges);
        (void)loaded.size();
    }, 5);

    auto loaded = import_iges_from_string(iges);
    EXPECT_FALSE(loaded.empty());
    record_io("IO.IGES.Import/SingleBox", ms, iges.size());
}

// ═══════════════════════════════════════════════
//  STEP 基准
// ═══════════════════════════════════════════════

TEST(BenchmarkIO, STEP_Export_SingleBody) {
    auto body = make_box(10.0, 5.0, 3.0);

    std::string result;
    double ms = measure_ms([&]() {
        result = export_step({body});
    }, 5);

    EXPECT_FALSE(result.empty());
    record_io("IO.STEP.Export/SingleBox", ms, result.size());
}

TEST(BenchmarkIO, STEP_Export_Sphere) {
    auto body = make_sphere(5.0, 16, 8);

    std::string result;
    double ms = measure_ms([&]() {
        result = export_step({body});
    }, 5);

    EXPECT_FALSE(result.empty());
    record_io("IO.STEP.Export/Sphere16x8", ms, result.size());
}

TEST(BenchmarkIO, STEP_Export_Cylinder) {
    auto body = make_cylinder(3.0, 10.0, 32);

    std::string result;
    double ms = measure_ms([&]() {
        result = export_step({body});
    }, 5);

    EXPECT_FALSE(result.empty());
    record_io("IO.STEP.Export/Cylinder32", ms, result.size());
}

TEST(BenchmarkIO, STEP_RoundTrip_Box) {
    auto body = make_box(10.0, 5.0, 3.0);
    std::string step = export_step({body});

    double ms = measure_ms([&]() {
        auto loaded = import_step_from_string(step);
        (void)loaded.size();
    }, 5);

    auto loaded = import_step_from_string(step);
    EXPECT_FALSE(loaded.empty());
    record_io("IO.STEP.Import/SingleBox", ms, step.size());
}

// ═══════════════════════════════════════════════
//  大规模数据IO基准
// ═══════════════════════════════════════════════

TEST(BenchmarkIO, STEP_Export_LargeModel) {
    // 高细分球体 → 大量面 → 大 STEP 文件
    auto body = make_sphere(5.0, 32, 16);

    std::string result;
    double ms = measure_ms([&]() {
        result = export_step({body});
    }, 3);

    EXPECT_FALSE(result.empty());
    record_io("IO.STEP.Export/LargeSphere32x16", ms, result.size());
}

TEST(BenchmarkIO, IGES_Export_LargeModel) {
    auto body = make_sphere(5.0, 32, 16);

    std::string result;
    double ms = measure_ms([&]() {
        result = export_iges({body});
    }, 3);

    EXPECT_FALSE(result.empty());
    record_io("IO.IGES.Export/LargeSphere32x16", ms, result.size());
}

TEST(BenchmarkIO, MultiBody_Export) {
    // 多体导出
    std::vector<BrepModel> bodies = {
        make_box(3.0, 3.0, 3.0),
        make_sphere(2.0, 12, 6),
        make_cylinder(1.0, 5.0, 16),
        make_box(1.0, 1.0, 10.0),
    };

    std::string result;
    double ms = measure_ms([&]() {
        result = export_step(bodies);
    }, 3);

    EXPECT_FALSE(result.empty());
    record_io("IO.STEP.Export/MultiBody(4)", ms, result.size());
}