#include "Test_Fixtures.h"

#include <render_3D/base/Object_Access_p.h>
#include <render_3D/scene/Scene.h>
#include <render_3D/scene/Scene_Frame.h>

#include <gtest/gtest.h>

#include <filesystem>
#include <fstream>
#include <iterator>
#include <string>
#include <type_traits>

namespace renderive::render_3D {

TEST(Render3DSceneFrame, AttachOwnsMeshUntilDetach) {
    Scene scene;
    auto mesh = test::mesh_owner();
    const auto id = mesh->identity();
    std::weak_ptr<Mesh> lifetime = mesh.share();

    scene.update([&](Scene_Edit& edit) { edit.attach(mesh); });
    mesh.reset();
    EXPECT_FALSE(lifetime.expired());

    const auto frame = detail::Object_Access::make_frame(scene);
    ASSERT_EQ(frame.mesh_structure_changes.size(), 1U);
    EXPECT_EQ(frame.mesh_structure_changes.front().operation, Mesh_Structure_Operation::attach);
    ASSERT_EQ(frame.mesh_updates.size(), 1U);
    EXPECT_EQ(frame.mesh_updates.front().id, id);
    EXPECT_FALSE(lifetime.expired());

    scene.update([&](Scene_Edit& edit) { edit.detach(id); });
    EXPECT_TRUE(lifetime.expired());
    const auto detached = detail::Object_Access::make_frame(scene);
    ASSERT_EQ(detached.mesh_structure_changes.size(), 1U);
    EXPECT_EQ(detached.mesh_structure_changes.front().operation, Mesh_Structure_Operation::detach);
}


TEST(Render3DSceneFrame, AttachOwnsTextUntilDetach) {
    Scene scene;
    auto text = test::text_owner();
    const auto id = text->identity();
    std::weak_ptr<Text> lifetime = text.share();
    scene.update([&](Scene_Edit& edit) { edit.attach(text); });
    text.reset();
    EXPECT_FALSE(lifetime.expired());
    const auto frame = detail::Object_Access::make_frame(scene);
    ASSERT_EQ(frame.text_structure_changes.size(), 1U);
    ASSERT_EQ(frame.text_updates.size(), 1U);
    EXPECT_EQ(frame.text_structure_changes.front().operation, Text_Structure_Operation::attach);
    EXPECT_EQ(frame.text_updates.front().id, id);
    scene.update([&](Scene_Edit& edit) { edit.detach(id); });
    EXPECT_TRUE(lifetime.expired());
    const auto detached = detail::Object_Access::make_frame(scene);
    ASSERT_EQ(detached.text_structure_changes.size(), 1U);
    EXPECT_EQ(detached.text_structure_changes.front().operation, Text_Structure_Operation::detach);
}

TEST(Render3DSceneFrame, PublishedFrameIsIndependentFromLaterCacheMutation) {
    Scene scene;
    auto mesh = test::mesh_owner();
    scene.update([&](Scene_Edit& edit) { edit.attach(mesh); });
    const auto first = detail::Object_Access::make_frame(scene);
    ASSERT_EQ(first.mesh_updates.size(), 1U);

    Matrix4 translated;
    translated.elements[13] = 3.0F;
    mesh->place(translated);
    EXPECT_NE(first.mesh_updates.front().transform, translated);

    const auto second = detail::Object_Access::make_frame(scene);
    ASSERT_EQ(second.mesh_updates.size(), 1U);
    EXPECT_EQ(second.mesh_updates.front().transform, translated);
    EXPECT_NE(first.mesh_updates.front().transform, second.mesh_updates.front().transform);
}

TEST(Render3DSceneFrame, ImplRelationshipsBecomePointerFreeFrameValues) {
    Scene scene;
    auto image = std::make_shared<Image_Data>();
    image->width = 1;
    image->height = 1;
    image->rgba8 = {255, 255, 255, 255};
    auto texture = renderive_Owner<Texture>::make(Texture_Properties{image});
    auto material = test::material_owner();
    material->use_texture(texture);
    auto mesh = test::mesh_owner(test::triangle_geometry(), material);
    auto camera = test::camera_owner();
    scene.update([&](Scene_Edit& edit) {
        edit.attach(mesh);
        edit.set_camera(camera);
    });

    const auto frame = detail::Object_Access::make_frame(scene);
    ASSERT_EQ(frame.texture_updates.size(), 1U);
    ASSERT_EQ(frame.material_updates.size(), 1U);
    ASSERT_EQ(frame.mesh_updates.size(), 1U);
    ASSERT_TRUE(frame.camera_change);
    EXPECT_TRUE(frame.camera_change->active);
    EXPECT_EQ(frame.material_updates.front().texture_id, texture->identity());
    EXPECT_EQ(frame.mesh_updates.front().material_id, material->identity());
    EXPECT_EQ(frame.mesh_updates.front().geometry, detail::Object_Access::rendered(*mesh).properties.geometry);

    static_assert(!std::is_pointer_v<decltype(Mesh_Frame_State::geometry)>);
    static_assert(std::is_copy_constructible_v<Scene3D_Frame_Data>);
}

TEST(Render3DSceneFrame, PublicFrameHeaderDoesNotExposeImplOrBackendTypes) {
    const auto path = std::filesystem::path(__FILE__).parent_path().parent_path() /
                      "render_3D" / "scene" / "Scene_Frame.h";
    std::ifstream input(path, std::ios::binary);
    ASSERT_TRUE(input.good());
    const std::string source{
        std::istreambuf_iterator<char>(input), std::istreambuf_iterator<char>()};
    EXPECT_EQ(source.find("Dvz"), std::string::npos);
    EXPECT_EQ(source.find("::Impl"), std::string::npos);
    EXPECT_EQ(source.find("Snapshot"), std::string::npos);
    EXPECT_EQ(source.find("Mesh*"), std::string::npos);
    EXPECT_EQ(source.find("Camera*"), std::string::npos);
    EXPECT_EQ(source.find("Material*"), std::string::npos);
    EXPECT_EQ(source.find("Texture*"), std::string::npos);
    EXPECT_EQ(source.find("Text*"), std::string::npos);
    EXPECT_EQ(source.find("renderive_Owner"), std::string::npos);
    EXPECT_EQ(source.find("_p.h"), std::string::npos);
}

} // namespace renderive::render_3D