#include <catch2/catch_all.hpp>

#include <catch2/catch_test_macros.hpp>
#include <catch2/matchers/catch_matchers.hpp>
#include <catch2/matchers/catch_matchers_floating_point.hpp>
#include <catch2/catch_message.hpp>
#include <catch2/generators/catch_generators.hpp>
#include "test_helpers.hpp"
#include "libslic3r/GCode/PreciseSeam.hpp"

#include <algorithm>
#include "libslic3r/Point.hpp"
#include "libslic3r/Polygon.hpp"
#include "libslic3r/Model.hpp"
#include "libslic3r/Print.hpp"
#include "libslic3r/Layer.hpp"
#include <vector>
#include <utility>
#include "libslic3r/libslic3r.h"
#include "libslic3r/GCode/SeamPlacer.hpp"
#include <cstddef>

using namespace Slic3r;

namespace {
Point mm(double x, double y) { return Point(scale_(x), scale_(y)); }

Polygon rectangle(double x0, double y0, double x1, double y1)
{
    // Counterclockwise contours match the modifier-slice cache contract.
    return Polygon(Points{mm(x0, y0), mm(x1, y0), mm(x1, y1), mm(x0, y1)});
}

struct SeamFixture {
    Model model;
    Print print;
    Model modifiers;
    Layer *layer = nullptr;
    PreciseSeam::ModifierSlicesCache cache;

    SeamFixture()
    {
        // Only the layer/PrintObject context is needed; clipping uses explicit cached slices below.
        Test::init_print({Test::cube(20)}, print, model, {{"raft_layers", "0"}});
        REQUIRE(print.objects().size() == 1);
        PrintObject *object = print.get_object(0);
        layer = object->add_layer(int(object->slicing_parameters().raft_layers()), 0.2, 0.2, 0.1);
        modifiers.add_object();
    }

    const ModelVolume *add(ModelVolumeType type, Polygons slices)
    {
        // These volumes own cache keys; mesh slicing is deliberately outside this geometry fixture.
        ModelVolume *volume = modifiers.objects.front()->add_volume(Test::cube(1));
        volume->set_type(type);
        cache.emplace(volume, std::vector<Polygons>{std::move(slices)});
        return volume;
    }
};

void check_square_boundary(const Polygon &polygon)
{
    // Wrong insertion edges can retrace a side without changing area: check length as well.
    CHECK_THAT(unscale<double>(polygon.length()), Catch::Matchers::WithinAbs(80.0, 0.00001));
    for (const Point &p : polygon.points) {
        CAPTURE(p.x(), p.y());
        CHECK(p.x() >= scale_(0));
        CHECK(p.x() <= scale_(20));
        CHECK(p.y() >= scale_(0));
        CHECK(p.y() <= scale_(20));
        const bool on_boundary = p.x() == 0 || p.x() == scale_(20) || p.y() == 0 || p.y() == scale_(20);
        CHECK(on_boundary);
    }
}

void require_vertex(const Polygon &polygon, const Point &point)
{
    // Integer coordinates make the micron transition helpers exact on these axis-aligned edges.
    CAPTURE(point.x(), point.y());
    REQUIRE(std::find(polygon.points.begin(), polygon.points.end(), point) != polygon.points.end());
}
} // namespace

TEST_CASE("Strong seam modes select the requested location on a clipped side", "[PreciseSeam]")
{
    const auto mode = GENERATE(ModelVolumeType::PRECISE_SEAM_LEFT, ModelVolumeType::PRECISE_SEAM_CENTER,
                              ModelVolumeType::PRECISE_SEAM_RIGHT);
    SeamFixture fixture;
    // Clipper may collapse all three original collinear edges into one.
    Polygon perimeter(Points{mm(0, 0), mm(2, 0), mm(4, 0), mm(8, 0), mm(20, 0), mm(20, 20), mm(0, 20)});
    const ModelVolume *modifier = fixture.add(mode, {rectangle(1, -2, 13, 2)});
    PreciseSeam::PreciseSeamWarnings warnings;
    const auto seam = PreciseSeam::insert_strong_seam_point({modifier}, perimeter, fixture.layer, fixture.cache, &warnings);
    REQUIRE(seam.has_value());
    const double expected_x = mode == ModelVolumeType::PRECISE_SEAM_LEFT ? 1.0 :
                              mode == ModelVolumeType::PRECISE_SEAM_RIGHT ? 13.0 : 7.0;
    CHECK(*seam == mm(expected_x, 0));
    require_vertex(perimeter, mm(expected_x - 0.001, 0));
    require_vertex(perimeter, mm(expected_x + 0.001, 0));
    check_square_boundary(perimeter);
    CHECK_FALSE(warnings.through_body.load());
    CHECK_FALSE(warnings.full_containment.load());
    CHECK_FALSE(warnings.multiple_intersections.load());
}

TEST_CASE("Center seams preserve the edge order at vertices and across the contour origin", "[PreciseSeam]")
{
    const bool wrap = GENERATE(false, true);
    SeamFixture fixture;
    Polygon perimeter(Points{mm(0, 0), mm(4, 0), mm(20, 0), mm(20, 20), mm(0, 20)});
    // Symmetric cuts put the arc midpoint exactly on an existing vertex, including vertex zero.
    const Polygon cut = wrap ? rectangle(-2, -2, 4, 4) : rectangle(1, -2, 7, 2);
    const ModelVolume *modifier = fixture.add(ModelVolumeType::PRECISE_SEAM_CENTER, {cut});
    const auto seam = PreciseSeam::insert_strong_seam_point({modifier}, perimeter, fixture.layer, fixture.cache);
    REQUIRE(seam.has_value());
    CHECK(*seam == (wrap ? mm(0, 0) : mm(4, 0)));
    require_vertex(perimeter, wrap ? mm(0, 0.001) : mm(3.999, 0));
    require_vertex(perimeter, wrap ? mm(0.001, 0) : mm(4.001, 0));
    check_square_boundary(perimeter);
}

TEST_CASE("Center seams land on the closing edge", "[PreciseSeam]")
{
    SeamFixture fixture;
    Polygon perimeter = rectangle(0, 0, 20, 20);
    const auto *modifier = fixture.add(ModelVolumeType::PRECISE_SEAM_CENTER, {rectangle(-2, 3, 2, 9)});
    const auto seam = PreciseSeam::insert_strong_seam_point({modifier}, perimeter, fixture.layer, fixture.cache);
    REQUIRE(seam.has_value());
    CHECK(*seam == mm(0, 6));
    require_vertex(perimeter, mm(0, 5.999));
    require_vertex(perimeter, mm(0, 6.001));
    check_square_boundary(perimeter);
}

TEST_CASE("Coincident weak boundaries do not prevent later boundary refinement", "[PreciseSeam][Regression]")
{
    SeamFixture fixture;
    Polygon perimeter = rectangle(0, 0, 20, 20);
    // Duplicate boundaries used to stall the reverse cursor before reaching the separate segment.
    const auto *a = fixture.add(ModelVolumeType::PRECISE_SEAM_BLOCKED, {rectangle(2, -2, 6, 2)});
    const auto *b = fixture.add(ModelVolumeType::PRECISE_SEAM_NEUTRAL, {rectangle(2, -2, 6, 2)});
    const auto *c = fixture.add(ModelVolumeType::PRECISE_SEAM_BLOCKED, {rectangle(10, -2, 14, 2)});
    const auto segments = PreciseSeam::collect_weak_modifier_segments({c, b, a}, perimeter, fixture.layer, fixture.cache);
    REQUIRE(segments.size() == 3);
    for (double x : {1.999, 6.001, 9.999, 14.001})
        require_vertex(perimeter, mm(x, 0));
    check_square_boundary(perimeter);
}

TEST_CASE("Weak boundaries sharing a vertex refine both sides", "[PreciseSeam]")
{
    SeamFixture fixture;
    Polygon perimeter = rectangle(0, 0, 20, 20);
    const auto *a = fixture.add(ModelVolumeType::PRECISE_SEAM_BLOCKED, {rectangle(2, -2, 6, 2)});
    const auto *b = fixture.add(ModelVolumeType::PRECISE_SEAM_NEUTRAL, {rectangle(6, -2, 10, 2)});
    const auto segments = PreciseSeam::collect_weak_modifier_segments({a, b}, perimeter, fixture.layer, fixture.cache);
    REQUIRE(segments.size() == 2);
    require_vertex(perimeter, mm(5.999, 0));
    require_vertex(perimeter, mm(6.001, 0));
    check_square_boundary(perimeter);
}

TEST_CASE("Unsupported modifier sections are skipped with the appropriate warning", "[PreciseSeam]")
{
    const int scenario = GENERATE(0, 1, 2, 3);
    SeamFixture fixture;
    Polygon perimeter = rectangle(0, 0, 20, 20);
    const Points original = perimeter.points;
    Polygons slices;
    if (scenario == 0) slices = {rectangle(30, 30, 40, 40)}; // Disjoint bounds.
    if (scenario == 1) slices = {rectangle(2, 2, 4, 4)};     // Wholly inside; no common boundary.
    if (scenario == 2) slices = {rectangle(-2, -2, 22, 22)}; // Contains the entire perimeter.
    if (scenario == 3) {
        Polygon hole = rectangle(2, 2, 4, 4);
        hole.reverse();
        slices = {rectangle(-2, -2, 22, 22), hole};
    }
    const auto *modifier = fixture.add(ModelVolumeType::PRECISE_SEAM_CENTER, std::move(slices));
    PreciseSeam::PreciseSeamWarnings warnings;
    CHECK_FALSE(PreciseSeam::insert_strong_seam_point({modifier}, perimeter, fixture.layer, fixture.cache, &warnings).has_value());
    CHECK(perimeter.points == original);
    CHECK(warnings.full_containment.load() == (scenario == 2));
    CHECK(warnings.multiply_connected.load() == (scenario == 3));
    CHECK_FALSE(warnings.multiple_intersections.load());
    CHECK_FALSE(warnings.through_body.load());
}

TEST_CASE("Strong modifiers warn when another slice polygon also intersects the perimeter", "[PreciseSeam]")
{
    SeamFixture fixture;
    Polygon perimeter = rectangle(0, 0, 20, 20);
    // One helper has two disconnected sections; only its first section supplies the seam.
    const auto *modifier = fixture.add(ModelVolumeType::PRECISE_SEAM_CENTER,
                                       {rectangle(2, -2, 6, 2), rectangle(12, -2, 16, 2)});
    PreciseSeam::PreciseSeamWarnings warnings;
    const auto seam = PreciseSeam::insert_strong_seam_point({modifier}, perimeter, fixture.layer, fixture.cache, &warnings);
    REQUIRE(seam.has_value());
    CHECK(*seam == mm(4, 0));
    CHECK(warnings.multiple_intersections.load());
    CHECK_FALSE(warnings.through_body.load());
    CHECK_FALSE(warnings.full_containment.load());
    CHECK_FALSE(warnings.multiply_connected.load());
    check_square_boundary(perimeter);
}

TEST_CASE("Modifiers crossing the entire body raise a through body warning", "[PreciseSeam]")
{
    const bool strong = GENERATE(false, true);
    CAPTURE(strong);
    SeamFixture fixture;
    Polygon perimeter = rectangle(0, 0, 20, 20);
    // The strip exits on opposite sides, leaving two exterior pieces. None of the clipped
    // vertices matches a square corner, so this also exercises the general segment-extraction path.
    const auto type = strong ? ModelVolumeType::PRECISE_SEAM_CENTER : ModelVolumeType::PRECISE_SEAM_BLOCKED;
    const auto *modifier = fixture.add(type, {rectangle(8, -2, 12, 22)});
    PreciseSeam::PreciseSeamWarnings warnings;
    if (strong) {
        const auto seam = PreciseSeam::insert_strong_seam_point({modifier}, perimeter, fixture.layer, fixture.cache, &warnings);
        REQUIRE(seam.has_value());
        CHECK(seam->x() == mm(10, 0).x());
        // Either boundary segment may be encountered first by the clipping traversal.
        const bool on_crossed_side = seam->y() == 0 || seam->y() == mm(0, 20).y();
        CHECK(on_crossed_side);
    } else {
        const auto segments = PreciseSeam::collect_weak_modifier_segments({modifier}, perimeter, fixture.layer, fixture.cache, &warnings);
        REQUIRE_FALSE(segments.empty());
    }
    CHECK(warnings.through_body.load());
    CHECK_FALSE(warnings.multiple_intersections.load()); // The clipped strip is one polygon.
    CHECK_FALSE(warnings.full_containment.load());
    CHECK_FALSE(warnings.multiply_connected.load());
    check_square_boundary(perimeter);
}

TEST_CASE("Modifier hierarchy keeps strong order and applies the highest weak priority last", "[PreciseSeam]")
{
    const auto high_type = GENERATE(ModelVolumeType::PRECISE_SEAM_BLOCKED, ModelVolumeType::PRECISE_SEAM_NEUTRAL,
                                   ModelVolumeType::PRECISE_SEAM_ENFORCED);
    const auto expected_type = high_type == ModelVolumeType::PRECISE_SEAM_BLOCKED ? SeamPlacerImpl::EnforcedBlockedSeamPoint::Blocked :
                               high_type == ModelVolumeType::PRECISE_SEAM_NEUTRAL ? SeamPlacerImpl::EnforcedBlockedSeamPoint::Neutral :
                                                                                  SeamPlacerImpl::EnforcedBlockedSeamPoint::Enforced;
    SeamFixture fixture;
    const auto *strong_a = fixture.add(ModelVolumeType::PRECISE_SEAM_CENTER, {rectangle(1, -2, 3, 2)});
    const auto *strong_b = fixture.add(ModelVolumeType::PRECISE_SEAM_CENTER, {rectangle(11, -2, 13, 2)});
    const auto *high = fixture.add(high_type, {rectangle(2, -2, 6, 2)});
    const auto low_type = high_type == ModelVolumeType::PRECISE_SEAM_ENFORCED ? ModelVolumeType::PRECISE_SEAM_BLOCKED :
                                                                                           ModelVolumeType::PRECISE_SEAM_ENFORCED;
    const auto *low = fixture.add(low_type, {rectangle(2, -2, 6, 2)});
    std::vector<const ModelVolume*> strong, weak;
    bool has_strong = false;
    PreciseSeam::init_precise_seam_data(strong, weak, has_strong, fixture.modifiers.objects.front());
    REQUIRE(has_strong);
    CHECK(strong == std::vector<const ModelVolume*>{strong_a, strong_b});
    CHECK(weak == std::vector<const ModelVolume*>{low, high});
    Polygon perimeter = rectangle(0, 0, 20, 20);
    const auto seam = PreciseSeam::insert_strong_seam_point(strong, perimeter, fixture.layer, fixture.cache);
    REQUIRE(seam.has_value());
    CHECK(*seam == mm(2, 0));

    perimeter = rectangle(0, 0, 20, 20);
    const auto segments = PreciseSeam::collect_weak_modifier_segments(weak, perimeter, fixture.layer, fixture.cache);
    REQUIRE(segments.size() == 2);
    PrintObjectSeamData::LayerSeams result;
    result.perimeters.emplace_back();
    auto &loop = result.perimeters.back();
    // Include a preceding candidate to exercise nonzero global layer indices.
    result.points.emplace_back(Vec3f(-1, -1, 0), loop, 0, SeamPlacerImpl::EnforcedBlockedSeamPoint::Neutral);
    loop.start_index = 1;
    for (const Point &p : perimeter.points) {
        // Match production's double-to-float conversion: weak boundary lookup uses exact equality.
        const Vec2f position = unscale(p).cast<float>();
        result.points.emplace_back(Vec3f(position.x(), position.y(), 0), loop, 0,
                                   SeamPlacerImpl::EnforcedBlockedSeamPoint::Neutral);
    }
    loop.end_index = result.points.size();
    bool enforced = false;
    PreciseSeam::apply_weak_modifiers_to_perimeter(segments, result, loop, enforced);
    size_t patch_count = 0;
    for (size_t i = loop.start_index; i < loop.end_index; ++i) {
        const auto &candidate = result.points[i];
        // Axis-aligned input and interpolation keep y exactly zero; this classifies, rather than measures, the patch.
        const bool in_patch = candidate.position.y() == 0 && candidate.position.x() >= 2 && candidate.position.x() <= 6;
        CHECK(candidate.type == (in_patch ? expected_type :
                                          SeamPlacerImpl::EnforcedBlockedSeamPoint::Neutral));
        if (in_patch) ++patch_count;
    }
    CHECK(patch_count >= 2);
    if (high_type == ModelVolumeType::PRECISE_SEAM_ENFORCED) {
        // Four millimetres of enforcement must be subdivided, not just marked at its endpoints.
        CHECK(enforced);
        CHECK(patch_count >= size_t(4.0f / SeamPlacer::enforcer_oversampling_distance));
    }
    CHECK(result.points.front().type == SeamPlacerImpl::EnforcedBlockedSeamPoint::Neutral);
}