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

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

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

TEST(MeasureTest, Volume_UnitBox) {
    auto box = make_box(2, 2, 2);
    double vol = volume(box);
    EXPECT_NEAR(vol, 8.0, 0.2);
}

TEST(MeasureTest, Volume_LargeBox) {
    auto box = make_box(10, 5, 3);
    double vol = volume(box);
    EXPECT_NEAR(vol, 150.0, 1.0);
}

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

TEST(MeasureTest, SurfaceArea_UnitBox) {
    auto box = make_box(2, 2, 2);
    double area = surface_area(box);
    EXPECT_NEAR(area, 24.0, 0.5);
}

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);
    EXPECT_NEAR(area, expected, 2.0);
}

// ═══════════════════════════════════════════════════════════
//  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);
    auto box2 = make_box(1, 1, 1);
    double d = distance(box1, box2);
    EXPECT_NEAR(d, 0.0, 0.1);
}

TEST(MeasureTest, Distance_OverlappingBoxes) {
    auto box1 = make_box(2, 2, 2);
    auto box2 = make_box(2, 2, 2);
    double d = distance(box1, box2);
    EXPECT_NEAR(d, 0.0, 0.1);
}

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);
}

// ═══════════════════════════════════════════════════════════
//  Mass properties
// ═══════════════════════════════════════════════════════════

TEST(MassPropertiesTest, Box_Volume) {
    auto box = make_box(2, 2, 2);
    auto mp = mass_properties(box);
    EXPECT_NEAR(mp.volume, 8.0, 1.0);
}

TEST(MassPropertiesTest, Box_CentroidAtOrigin) {
    auto box = make_box(2, 2, 2);
    auto mp = mass_properties(box);
    EXPECT_NEAR(mp.centroid.x(), 0.0, 0.3);
    EXPECT_NEAR(mp.centroid.y(), 0.0, 0.3);
    EXPECT_NEAR(mp.centroid.z(), 0.0, 0.3);
}

TEST(MassPropertiesTest, Box_InertiaPositive) {
    auto box = make_box(2, 2, 2);
    auto mp = mass_properties(box);
    EXPECT_GT(mp.inertia(0,0), 0.0);
    EXPECT_GT(mp.inertia(1,1), 0.0);
    EXPECT_GT(mp.inertia(2,2), 0.0);
}

TEST(MassPropertiesTest, Box_GyrationRadii) {
    auto box = make_box(2, 2, 2);
    auto mp = mass_properties(box);
    EXPECT_GT(mp.gyration_radii.x(), 0.0);
    EXPECT_GT(mp.gyration_radii.y(), 0.0);
    EXPECT_GT(mp.gyration_radii.z(), 0.0);
}

TEST(MassPropertiesTest, EmptyBody) {
    BrepModel empty;
    auto mp = mass_properties(empty);
    EXPECT_NEAR(mp.volume, 0.0, 1e-10);
}

// ═══════════════════════════════════════════════════════════
//  Clearance (gap analysis)
// ═══════════════════════════════════════════════════════════

TEST(ClearanceTest, SeparatedBoxes) {
    auto box1 = make_box(1, 1, 1);
    auto box2 = make_box(1, 1, 1);
    double c = clearance(box1, box2);
    EXPECT_GE(c, 0.0);
}

TEST(ClearanceTest, OverlappingBoxes) {
    auto box = make_box(2, 2, 2);
    EXPECT_NEAR(clearance(box, box), 0.0, 1e-6);
}

// ═══════════════════════════════════════════════════════════
//  Assembly mass properties
// ═══════════════════════════════════════════════════════════

TEST(AssemblyMassTest, SinglePart) {
    Assembly assy("test");
    assy.root.add_part("box", make_box(2, 2, 2));
    auto mp = assembly_mass_properties(assy.root);
    EXPECT_NEAR(mp.volume, 8.0, 1.0);
}

TEST(AssemblyMassTest, TwoPartsCombined) {
    Assembly assy("test");
    assy.root.add_part("box1", make_box(2, 2, 2));
    assy.root.add_part("box2", make_box(2, 2, 2));
    auto mp = assembly_mass_properties(assy.root);
    EXPECT_NEAR(mp.volume, 16.0, 2.0);
}

TEST(AssemblyMassTest, NestedAssembly) {
    Assembly assy("test");
    auto* sub = assy.root.add_subassembly("sub");
    sub->add_part("box", make_box(2, 2, 2));
    assy.root.add_part("box2", make_box(2, 2, 2));
    auto mp = assembly_mass_properties(assy.root);
    EXPECT_NEAR(mp.volume, 16.0, 2.0);
}

TEST(AssemblyMassTest, EmptyAssembly) {
    Assembly assy("test");
    auto mp = assembly_mass_properties(assy.root);
    EXPECT_NEAR(mp.volume, 0.0, 1e-10);
}

// ═══════════════════════════════════════════════════════════
//  BOM (Bill of Materials)
// ═══════════════════════════════════════════════════════════

TEST(BomTest, SinglePart) {
    Assembly assy("test");
    assy.root.add_part("bracket", make_box(2, 2, 2));
    auto bom = generate_bom(assy.root);
    ASSERT_EQ(bom.size(), 1u);
    EXPECT_EQ(bom[0].name, "bracket");
    EXPECT_EQ(bom[0].quantity, 1);
}

TEST(BomTest, MultipleSameParts) {
    Assembly assy("test");
    assy.root.add_part("bolt", make_box(1, 1, 1));
    assy.root.add_part("bolt", make_box(1, 1, 1));
    assy.root.add_part("bolt", make_box(1, 1, 1));
    auto bom = generate_bom(assy.root);
    ASSERT_EQ(bom.size(), 1u);
    EXPECT_EQ(bom[0].quantity, 3);
}

TEST(BomTest, DifferentParts) {
    Assembly assy("test");
    assy.root.add_part("base", make_box(4, 4, 1));
    assy.root.add_part("pillar", make_cylinder(1, 8));
    assy.root.add_part("top", make_box(4, 4, 1));
    auto bom = generate_bom(assy.root);
    ASSERT_EQ(bom.size(), 3u);
}

TEST(BomTest, NestedBom) {
    Assembly assy("test");
    auto* sub = assy.root.add_subassembly("sub_assy");
    sub->add_part("pin", make_cylinder(0.5, 2));
    sub->add_part("pin", make_cylinder(0.5, 2));
    assy.root.add_part("frame", make_box(5, 5, 1));
    auto bom = generate_bom(assy.root);
    EXPECT_GE(bom.size(), 2u);
}

TEST(BomTest, EmptyAssembly) {
    Assembly assy("test");
    auto bom = generate_bom(assy.root);
    EXPECT_TRUE(bom.empty());
}

// ═══════════════════════════════════════════════════════════
//  Wall thickness analysis
// ═══════════════════════════════════════════════════════════

TEST(WallThicknessTest, Box) {
    auto box = make_box(4, 4, 4);          // 4×4×4 box
    auto result = analyze_wall_thickness(box, 3);
    // For a 4×4×4 box, wall thickness ~4.0 (opposite face distance)
    EXPECT_GT(result.min_thickness, 0.0);
    EXPECT_GT(result.max_thickness, 0.0);
    EXPECT_GT(result.avg_thickness, 0.0);
}

TEST(WallThicknessTest, EmptyBody) {
    BrepModel empty;
    auto result = analyze_wall_thickness(empty);
    EXPECT_NEAR(result.min_thickness, 0.0, 1e-10);
}

TEST(WallThicknessTest, ThinWallDetection) {
    // 4×4×0.5 thin plate
    auto plate = make_box(4, 4, 0.5);
    auto result = analyze_wall_thickness(plate, 3);
    EXPECT_GT(result.min_thickness, 0.0);
    EXPECT_LT(result.min_thickness, 1.0);  // thin
}