#include <gtest/gtest.h>
#include "vde/brep/brep.h"
#include "vde/brep/modeling.h"
#include "vde/brep/measure.h"
#include <cmath>

using namespace vde::brep;
using namespace vde::core;

// ═══════════════════════════════════════════════════════════
//  Volume measurements
// ═══════════════════════════════════════════════════════════

TEST(MeasureTest, Volume_UnitBox) {
    // 2×2×2 box centered at origin → volume = 8.0
    auto box = make_box(2, 2, 2);
    double vol = volume(box);
    EXPECT_NEAR(vol, 8.0, 0.2) << "Volume of 2×2×2 box should be ~8.0";
}

TEST(MeasureTest, Volume_LargeBox) {
    auto box = make_box(10, 5, 3); // volume = 150
    double vol = volume(box);
    EXPECT_NEAR(vol, 150.0, 1.0) << "Volume of 10×5×3 box should be ~150";
}

// ═══════════════════════════════════════════════════════════
//  Surface area measurements
// ═══════════════════════════════════════════════════════════

TEST(MeasureTest, SurfaceArea_UnitBox) {
    // 2×2×2 box: 6 faces × 4 = 24.0
    auto box = make_box(2, 2, 2);
    double area = surface_area(box);
    EXPECT_NEAR(area, 24.0, 0.5) << "Surface area of 2×2×2 box should be ~24.0";
}

TEST(MeasureTest, SurfaceArea_LargeBox) {
    auto box = make_box(10, 5, 3);
    double area = surface_area(box);
    double expected = 2.0 * (10*5 + 10*3 + 5*3); // 190
    EXPECT_NEAR(area, expected, 2.0) << "Surface area of 10×5×3 box should be ~" << expected;
}

// ═══════════════════════════════════════════════════════════
//  Centroid measurements
// ═══════════════════════════════════════════════════════════

TEST(MeasureTest, Centroid_BoxAtOrigin) {
    auto box = make_box(2, 2, 2);
    auto c = centroid(box);
    EXPECT_NEAR(c.x(), 0.0, 0.01);
    EXPECT_NEAR(c.y(), 0.0, 0.01);
    EXPECT_NEAR(c.z(), 0.0, 0.01);
}

// ═══════════════════════════════════════════════════════════
//  Distance measurements
// ═══════════════════════════════════════════════════════════

TEST(MeasureTest, Distance_SeparatedBoxes) {
    auto box1 = make_box(1, 1, 1);    // centered at origin, half-size 0.5

    // We can't easily translate boxes, but make_box creates centered boxes
    // so we test two boxes at origin — they overlap
    auto box2 = make_box(1, 1, 1);
    double d = distance(box1, box2);
    // Two identical boxes at origin → overlap → distance ≈ 0
    EXPECT_NEAR(d, 0.0, 0.1) << "Overlapping boxes should have distance ~0";
}

TEST(MeasureTest, Distance_OverlappingBoxes) {
    auto box1 = make_box(2, 2, 2);
    auto box2 = make_box(2, 2, 2);
    double d = distance(box1, box2);
    // Overlapping boxes
    EXPECT_NEAR(d, 0.0, 0.1) << "Overlapping boxes should have distance ~0";
}

// ═══════════════════════════════════════════════════════════
//  Integration: volume + surface area consistency
// ═══════════════════════════════════════════════════════════

TEST(MeasureTest, Volume_NonNegative) {
    auto box = make_box(2, 2, 2);
    EXPECT_GE(volume(box), 0.0);
}

TEST(MeasureTest, SurfaceArea_NonNegative) {
    auto box = make_box(2, 2, 2);
    EXPECT_GE(surface_area(box), 0.0);
}

TEST(MeasureTest, Distance_NonNegative) {
    auto box1 = make_box(1, 1, 1);
    auto box2 = make_box(1, 1, 1);
    EXPECT_GE(distance(box1, box2), 0.0);
}