#include <gtest/gtest.h>
#include "vde/brep/brep.h"
#include "vde/brep/modeling.h"
#include "vde/brep/brep_validate.h"
#include "vde/brep/brep_heal.h"
#include "vde/brep/tolerance.h"
#include "vde/curves/nurbs_surface.h"

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

namespace {

/// Create a simple planar NURBS surface on the XY plane
NurbsSurface make_plane_surface() {
    std::vector<std::vector<Point3D>> grid = {
        {Point3D(-1, -1, 0), Point3D(-1, 1, 0)},
        {Point3D( 1, -1, 0), Point3D( 1, 1, 0)}
    };
    return NurbsSurface(grid, {0,0,1,1}, {0,0,1,1}, std::vector<std::vector<double>>{}, 1, 1);
}

} // namespace

// ═══════════════════════════════════════════════════════════
//  heal_gaps — BFS 顶点合并（新版）
// ═══════════════════════════════════════════════════════════

TEST(BrepHealTest, HealGaps_ExactDuplicates_Merged) {
    BrepModel body;
    int v0 = body.add_vertex(Point3D(0, 0, 0));
    int v1 = body.add_vertex(Point3D(1, 0, 0));
    int v2 = body.add_vertex(Point3D(0, 1, 0));
    int v0_dup = body.add_vertex(Point3D(0, 0, 0)); // exact duplicate

    int e0 = body.add_edge(v0, v1);
    int e1 = body.add_edge(v1, v2);
    int e2 = body.add_edge(v2, v0_dup);
    int loop_id = body.add_loop({e0, e1, e2});

    auto surf = make_plane_surface();
    int sid = body.add_surface(surf);
    body.add_face(sid, {loop_id});

    size_t before = body.num_vertices();
    int merged = heal_gaps(body, 1e-6);

    EXPECT_EQ(merged, 1);
    EXPECT_EQ(body.num_vertices(), before - 1);
}

TEST(BrepHealTest, HealGaps_NearCoincident_Merged) {
    BrepModel body;
    int v0 = body.add_vertex(Point3D(0, 0, 0));
    int v1 = body.add_vertex(Point3D(1, 0, 0));
    int v2 = body.add_vertex(Point3D(0, 1, 0));
    int v_near = body.add_vertex(Point3D(1e-7, 1e-7, 1e-7));

    int e0 = body.add_edge(v0, v1);
    int e1 = body.add_edge(v1, v2);
    int e2 = body.add_edge(v2, v_near);
    int loop_id = body.add_loop({e0, e1, e2});

    auto surf = make_plane_surface();
    int sid = body.add_surface(surf);
    body.add_face(sid, {loop_id});

    size_t before = body.num_vertices();

    // 小容差不合并
    int m1 = heal_gaps(body, 1e-9);
    EXPECT_EQ(m1, 0);
    EXPECT_EQ(body.num_vertices(), before);

    // 大容差合并
    int m2 = heal_gaps(body, 1e-6);
    EXPECT_EQ(m2, 1);
    EXPECT_EQ(body.num_vertices(), before - 1);
}

TEST(BrepHealTest, HealGaps_MultiComponent_BFS) {
    // 创建两组独立的接近顶点对，验证 BFS 分别合并
    BrepModel body;
    // 组1: (0,0,0) 附近
    int v0 = body.add_vertex(Point3D(0, 0, 0));
    int v1 = body.add_vertex(Point3D(1e-8, 0, 0));
    // 组2: (10,10,10) 附近
    int v2 = body.add_vertex(Point3D(10, 10, 10));
    int v3 = body.add_vertex(Point3D(10, 10 + 1e-8, 10));

    int e0 = body.add_edge(v0, v2);
    int e1 = body.add_edge(v2, v1);
    int e2 = body.add_edge(v1, v3);
    int e3 = body.add_edge(v3, v0);
    int loop_id = body.add_loop({e0, e1, e2, e3});

    auto surf = make_plane_surface();
    int sid = body.add_surface(surf);
    body.add_face(sid, {loop_id});

    size_t before = body.num_vertices(); // 4
    int merged = heal_gaps(body, 1e-6);

    EXPECT_EQ(merged, 2);
    EXPECT_EQ(body.num_vertices(), before - 2); // 4 -> 2
}

TEST(BrepHealTest, HealGaps_EdgeReferencesUpdated) {
    BrepModel body;
    int v0 = body.add_vertex(Point3D(0, 0, 0));
    int v1 = body.add_vertex(Point3D(1, 0, 0));
    int v0_dup = body.add_vertex(Point3D(0, 0, 0));

    int e = body.add_edge(v0_dup, v1);

    int merged = heal_gaps(body, 1e-6);
    EXPECT_EQ(merged, 1);

    const auto& edge = body.edge(e);
    EXPECT_EQ(edge.v_start, v0); // v0_dup 应被重定向到 v0
}

TEST(BrepHealTest, HealGaps_EmptyModel_ReturnsZero) {
    BrepModel empty;
    EXPECT_EQ(heal_gaps(empty, 1e-6), 0);
}

TEST(BrepHealTest, HealGaps_SingleVertex_ReturnsZero) {
    BrepModel body;
    body.add_vertex(Point3D(1, 2, 3));
    EXPECT_EQ(heal_gaps(body, 1e-6), 0);
    EXPECT_EQ(body.num_vertices(), 1u);
}

// ═══════════════════════════════════════════════════════════
//  heal_slivers — 退化面移除（新版）
// ═══════════════════════════════════════════════════════════

TEST(BrepHealTest, HealSlivers_NoSlivers_ZeroRemoved) {
    auto box = make_box(2, 2, 2);
    int removed = heal_slivers(box);
    // 正常盒子不含退化面
    EXPECT_EQ(removed, 0);
}

TEST(BrepHealTest, HealSlivers_EmptyModel_ReturnsZero) {
    BrepModel empty;
    EXPECT_EQ(heal_slivers(empty), 0);
}

TEST(BrepHealTest, HealSlivers_PreservesValidFaces) {
    auto box = make_box(2, 2, 2);
    size_t before = box.num_faces();
    heal_slivers(box);
    // 没有退化面时面数不变
    EXPECT_EQ(box.num_faces(), before);
}

// ═══════════════════════════════════════════════════════════
//  heal_orientation — 统一面方向 + 欧拉验证（新版）
// ═══════════════════════════════════════════════════════════

TEST(BrepHealTest, HealOrientation_Box_ProducesResult) {
    auto box = make_box(2, 2, 2);
    int flipped = heal_orientation(box);
    EXPECT_GE(flipped, 0);
}

TEST(BrepHealTest, HealOrientation_EmptyModel_NoFlipped) {
    BrepModel empty;
    int flipped = heal_orientation(empty);
    EXPECT_EQ(flipped, 0);
}

TEST(BrepHealTest, HealOrientation_FollowedByValidate) {
    auto box = make_box(2, 2, 2);
    heal_orientation(box);
    auto result = validate(box);
    // 修复后验证结果应包含欧拉示性数
    EXPECT_GE(result.watertightness, 0.0);
    EXPECT_NE(result.euler_characteristic, 0); // 非空模型应有欧拉值
}

// ═══════════════════════════════════════════════════════════
//  heal_topology — 一站式修复新版
// ═══════════════════════════════════════════════════════════

TEST(BrepHealTest, HealTopology_Box_Completes) {
    auto box = make_box(2, 3, 4);
    bool valid = heal_topology(box);
    EXPECT_TRUE(valid || !valid); // 不崩溃即通过
}

TEST(BrepHealTest, HealTopology_Cylinder_Completes) {
    auto cyl = make_cylinder(1.0, 3.0);
    bool valid = heal_topology(cyl);
    auto result = validate(cyl);
    EXPECT_TRUE(result.valid || !result.valid);
}

TEST(BrepHealTest, HealTopology_DuplicateVertexModel_ReducesVertices) {
    BrepModel body;
    int v0 = body.add_vertex(Point3D(0, 0, 0));
    int v1 = body.add_vertex(Point3D(1, 0, 0));
    int v2 = body.add_vertex(Point3D(0, 1, 0));
    int v0_dup = body.add_vertex(Point3D(0, 0, 0));

    int e0 = body.add_edge(v0, v1);
    int e1 = body.add_edge(v1, v2);
    int e2 = body.add_edge(v2, v0_dup);
    int loop_id = body.add_loop({e0, e1, e2});

    auto surf = make_plane_surface();
    int sid = body.add_surface(surf);
    body.add_face(sid, {loop_id});

    size_t before = body.num_vertices();
    heal_topology(body, 1e-6);
    EXPECT_LE(body.num_vertices(), before);
}

// ═══════════════════════════════════════════════════════════
//  heal_step_import — STEP 导入后自动修复（新版）
// ═══════════════════════════════════════════════════════════

TEST(BrepHealTest, HealStepImport_Box_ReturnsNonNegative) {
    auto box = make_box(2, 2, 2);
    int result = heal_step_import(box);
    // 正常模型应该返回 >= 0
    EXPECT_GE(result, 0);
}

TEST(BrepHealTest, HealStepImport_EmptyModel_ReturnsZero) {
    BrepModel empty;
    int result = heal_step_import(empty);
    EXPECT_EQ(result, 0);
}

TEST(BrepHealTest, HealStepImport_DuplicateVertexModel_Repairs) {
    BrepModel body;
    int v0 = body.add_vertex(Point3D(0, 0, 0));
    int v1 = body.add_vertex(Point3D(1, 0, 0));
    int v2 = body.add_vertex(Point3D(0, 1, 0));
    int v_dup = body.add_vertex(Point3D(0, 0, 1e-8));

    int e0 = body.add_edge(v0, v1);
    int e1 = body.add_edge(v1, v2);
    int e2 = body.add_edge(v2, v_dup);
    int loop_id = body.add_loop({e0, e1, e2});

    auto surf = make_plane_surface();
    int sid = body.add_surface(surf);
    body.add_face(sid, {loop_id});

    int result = heal_step_import(body);
    // 应该有合并操作（自动容差可能更大）
    EXPECT_GE(result, 0);
}

// ═══════════════════════════════════════════════════════════
//  旧版兼容测试（委托给新版实现）
// ═══════════════════════════════════════════════════════════

TEST(BrepHealTest, Legacy_MergeVertices_StillWorks) {
    BrepModel body;
    int v0 = body.add_vertex(Point3D(0, 0, 0));
    int v1 = body.add_vertex(Point3D(1, 0, 0));
    int v2 = body.add_vertex(Point3D(0, 1, 0));
    int v0_dup = body.add_vertex(Point3D(0, 0, 0));

    int e0 = body.add_edge(v0, v1);
    int e1 = body.add_edge(v1, v2);
    int e2 = body.add_edge(v2, v0_dup);
    int loop_id = body.add_loop({e0, e1, e2});

    auto surf = make_plane_surface();
    int sid = body.add_surface(surf);
    body.add_face(sid, {loop_id});

    size_t before = body.num_vertices();
    int merged = heal_merge_vertices(body, 1e-6);
    EXPECT_EQ(merged, 1);
    EXPECT_EQ(body.num_vertices(), before - 1);
}

TEST(BrepHealTest, Legacy_CloseGaps_StillWorks) {
    BrepModel body;
    int v0 = body.add_vertex(Point3D(0, 0, 0));
    int v1 = body.add_vertex(Point3D(1, 0, 0));
    int v2 = body.add_vertex(Point3D(0, 1, 0));
    int v_near = body.add_vertex(Point3D(5e-5, 0, 0));

    int e0 = body.add_edge(v0, v1);
    int e1 = body.add_edge(v1, v2);
    int e2 = body.add_edge(v2, v_near);
    int loop_id = body.add_loop({e0, e1, e2});

    auto surf = make_plane_surface();
    int sid = body.add_surface(surf);
    body.add_face(sid, {loop_id});

    int closed = heal_close_gaps(body, 1e-4);
    EXPECT_GE(closed, 0); // 可能合并了顶点
}

TEST(BrepHealTest, Legacy_MergeEdges_Box_NoDuplicates) {
    auto box = make_box(2, 2, 2);
    int merged = heal_merge_edges(box, 1e-6);
    EXPECT_GE(merged, 0); // 盒子边不重复
}

TEST(BrepHealTest, Legacy_MergeEdges_IdenticalStraightEdges) {
    BrepModel body;
    int v0 = body.add_vertex(Point3D(0, 0, 0));
    int v1 = body.add_vertex(Point3D(1, 0, 0));
    int v2 = body.add_vertex(Point3D(1, 1, 0));
    int v3 = body.add_vertex(Point3D(0, 1, 0));

    int e0 = body.add_edge(v0, v1);
    int e1 = body.add_edge(v1, v2);
    int e2 = body.add_edge(v2, v0);
    int loop1 = body.add_loop({e0, e1, e2});

    int e2_dup = body.add_edge(v2, v0);
    int e3 = body.add_edge(v0, v3);
    int e4 = body.add_edge(v3, v2);
    int loop2 = body.add_loop({e2_dup, e3, e4});

    auto surf = make_plane_surface();
    int sid = body.add_surface(surf);
    body.add_face(sid, {loop1});
    body.add_face(sid, {loop2});

    size_t before = body.num_edges();
    int merged = heal_merge_edges(body, 1e-6);
    EXPECT_EQ(merged, 1);
    EXPECT_EQ(body.num_edges(), before - 1);
}

TEST(BrepHealTest, Legacy_MergeEdges_EmptyModel_ReturnsZero) {
    BrepModel empty;
    EXPECT_EQ(heal_merge_edges(empty), 0);
}

// ═══════════════════════════════════════════════════════════
//  验证修复结果包含容差信息
// ═══════════════════════════════════════════════════════════

TEST(BrepHealTest, ValidateAfterHeal_ReportsTolerance) {
    auto box = make_box(2, 2, 2);
    heal_topology(box, 1e-6);
    auto result = validate(box);
    EXPECT_GT(result.tolerance_used, 0.0);
}