// SPDX-License-Identifier: MPL-2.0
//
// Tests du codec JSON provisoire du protocole Core - rendu (spec §5) : hex64, aller-retours,
// refus stricts et exemple conforme au texte de la spécification.
#include "sequa/3d/wire.hpp"

#include <doctest/doctest.h>

#include <cstdint>
#include <limits>
#include <optional>
#include <string>
#include <vector>

using namespace sequa::three_d;
using namespace sequa::three_d::wire;

namespace {

// Analyse sans exception : le codec ne doit jamais en laisser sortir.
[[nodiscard]] nlohmann::json parse_text(const std::string& text)
{
    return nlohmann::json::parse(text, nullptr, false);
}

// sans operator== défini : comparaison champ par champ.
[[nodiscard]] bool capabilities_equal(const EngineCapabilities& left, const EngineCapabilities& right)
{
    return left.engine_name == right.engine_name && left.engine_version == right.engine_version &&
           left.buffers == right.buffers && left.windowed == right.windowed && left.headless == right.headless &&
           left.player_input == right.player_input;
}

Transform sample_transform()
{
    Transform transform;
    transform.position = {1, -2.5, 3};
    transform.rotation = {0.0f, 0.70710678f, 0.0f, 0.70710678f};
    transform.scale = {2, 2, 2};
    return transform;
}

Visual sample_visual(Primitive primitive)
{
    Visual visual;
    visual.primitive = primitive;
    visual.size = {0.5, 1.5, 2.5};
    visual.color = {0.1f, 0.2f, 0.9f, 0.75f};
    visual.semantic_class = 42;
    return visual;
}

Transform sample_camera_transform()
{
    Transform transform;
    transform.position = {5, 6, 7};
    return transform;
}

Camera sample_camera()
{
    Camera camera;
    camera.transform = sample_camera_transform();
    camera.vertical_fov_deg = 60;
    camera.near_plane = 0.1f;
    camera.far_plane = 100;
    return camera;
}

// Valeurs de l'exemple conforme au texte de la spécification (protocole 0.1 §5).
Transform spec_transform()
{
    Transform transform;
    transform.position = {1, 2, 3};
    return transform;
}

Visual spec_visual()
{
    Visual visual;
    visual.primitive = Primitive::box;
    visual.size = {1, 1, 1};
    visual.color = {0.5f, 0.6f, 0.7f, 1.0f};
    visual.semantic_class = 2;
    return visual;
}

Camera spec_camera()
{
    Camera camera;
    camera.transform.position = {0, 2, 5}; // rotation et échelle par défaut
    return camera;
}

} // namespace

TEST_CASE("Wire : hex64, 16 caractères minuscules en sortie")
{
    CHECK(to_hex64(0ULL) == "0000000000000000");
    CHECK(to_hex64(1ULL) == "0000000000000001");
    CHECK(to_hex64(0x0123456789abcdefULL) == "0123456789abcdef");
    CHECK(to_hex64(std::numeric_limits<std::uint64_t>::max()) == "ffffffffffffffff");
}

TEST_CASE("Wire : from_hex64, de 1 à 16 caractères, majuscules ou minuscules")
{
    CHECK(from_hex64("0") == 0U);
    CHECK(from_hex64("f") == 15U);
    CHECK(from_hex64("01a") == 26U);
    CHECK(from_hex64("01A") == 26U);
    CHECK(from_hex64("0123456789abcdef") == 0x0123456789abcdefULL);
    CHECK(from_hex64("0123456789ABCDEF") == 0x0123456789abcdefULL);
    CHECK(from_hex64("ffffffffffffffff") == std::numeric_limits<std::uint64_t>::max());

    // Refus : vide, trop long, caractère hors alphabet.
    CHECK_FALSE(from_hex64("").has_value());
    CHECK_FALSE(from_hex64("0123456789abcdef0").has_value());
    CHECK_FALSE(from_hex64("01g").has_value());
    CHECK_FALSE(from_hex64("01fG").has_value());
    CHECK_FALSE(from_hex64(" 1").has_value());

    // Aller-retour sur des valeurs de tous les poids.
    const std::uint64_t values[] = {1U, 255U, 65536U, 0xdeadbeefcafef00dULL};
    for (const std::uint64_t value : values) {
        CHECK(from_hex64(to_hex64(value)) == value);
    }
}

TEST_CASE("Wire : create fait l'aller-retour, pour chaque primitive")
{
    for (const Primitive primitive : {Primitive::box, Primitive::sphere, Primitive::capsule, Primitive::plane}) {
        const SceneCommand command = CreateObject{0x1a2b3c4d5e6fULL, sample_transform(), sample_visual(primitive)};
        const nlohmann::json encoded = encode_command(command);
        CHECK(encoded["op"] == "create");
        CHECK(encoded["id"] == to_hex64(0x1a2b3c4d5e6fULL));

        std::string error;
        const std::optional<SceneCommand> decoded = decode_command(encoded, &error);
        REQUIRE(decoded.has_value());
        CHECK(error.empty());
        CHECK(*decoded == command);
        CHECK(std::get<CreateObject>(*decoded).visual.primitive == primitive);
    }
}

TEST_CASE("Wire : destroy, transform, visual et camera font l'aller-retour")
{
    {
        const SceneCommand command = DestroyObject{0xfeedface0001ULL};
        std::optional<SceneCommand> decoded = decode_command(encode_command(command));
        REQUIRE(decoded.has_value());
        CHECK(*decoded == command);
    }
    {
        const SceneCommand command = SetTransform{7ULL, sample_transform()};
        std::optional<SceneCommand> decoded = decode_command(encode_command(command));
        REQUIRE(decoded.has_value());
        CHECK(*decoded == command);
    }
    {
        const SceneCommand command = SetVisual{7ULL, sample_visual(Primitive::capsule)};
        std::optional<SceneCommand> decoded = decode_command(encode_command(command));
        REQUIRE(decoded.has_value());
        CHECK(*decoded == command);
    }
    {
        const SceneCommand command = SetCamera{sample_camera()};
        std::optional<SceneCommand> decoded = decode_command(encode_command(command));
        REQUIRE(decoded.has_value());
        CHECK(*decoded == command);
    }
}

TEST_CASE("Wire : un SceneDeltaMessage complet fait l'aller-retour")
{
    SceneDeltaMessage message;
    message.delta.world_version = 0xabcdef9876543210ULL;
    message.delta.commands = {
        SceneCommand{CreateObject{1ULL, sample_transform(), sample_visual(Primitive::box)}},
        SceneCommand{DestroyObject{2ULL}},
        SceneCommand{SetTransform{1ULL, sample_camera_transform()}},
        SceneCommand{SetVisual{1ULL, sample_visual(Primitive::sphere)}},
        SceneCommand{SetCamera{sample_camera()}},
    };
    message.tick = 0x123456789ULL;
    message.full = true;
    message.sent_at_us = 0x987654321ULL;

    std::string error;
    const std::optional<SceneDeltaMessage> decoded = decode_scene_delta(encode_scene_delta(message), &error);
    REQUIRE(decoded.has_value());
    CHECK(error.empty());
    CHECK(decoded->delta.world_version == message.delta.world_version);
    CHECK(decoded->delta.commands == message.delta.commands);
    CHECK(decoded->tick == message.tick);
    CHECK(decoded->full == message.full);
    CHECK(decoded->sent_at_us == message.sent_at_us);

    const nlohmann::json payload = encode_scene_delta(message);
    REQUIRE(payload.contains("worldVersion"));
    CHECK(payload["worldVersion"] == "abcdef9876543210");
    CHECK(payload["full"] == true);
}

TEST_CASE("Wire : les capacités font l'aller-retour")
{
    EngineCapabilities caps;
    caps.engine_name = "godot";
    caps.engine_version = "4.3.stable.official";
    caps.buffers = BufferSet::all();
    caps.windowed = true;
    caps.headless = false;

    const nlohmann::json encoded = encode_capabilities(caps);
    CHECK(encoded["engineName"] == "godot");
    CHECK(encoded["buffers"] == nlohmann::json::array({"color", "depth", "normals", "motion_vectors", "albedo",
                                                       "object_ids", "semantic_mask"}));

    std::string error;
    std::optional<EngineCapabilities> decoded = decode_capabilities(encoded, &error);
    REQUIRE(decoded.has_value());
    CHECK(error.empty());
    CHECK(capabilities_equal(*decoded, caps));

    // Sous-ensemble de tampons : BufferSet vide compris.
    caps.buffers = BufferSet{FrameBuffer::color, FrameBuffer::semantic_mask};
    decoded = decode_capabilities(encode_capabilities(caps));
    REQUIRE(decoded.has_value());
    CHECK(capabilities_equal(*decoded, caps));

    caps.buffers = BufferSet{};
    decoded = decode_capabilities(encode_capabilities(caps));
    REQUIRE(decoded.has_value());
    CHECK(decoded->buffers.empty());
}

TEST_CASE("Wire : refus d'un id 0 et d'un id non hexadécimal")
{
    for (const char* id : {"0", "0000000000000000"}) {
        const std::string text = std::string(R"({"op": "destroy", "id": ")") + id + R"("})";
        const nlohmann::json command = parse_text(text);
        REQUIRE(command.is_object());
        std::string error;
        CHECK_FALSE(decode_command(command, &error).has_value());
        CHECK_FALSE(error.empty());
    }

    std::string error;
    const nlohmann::json bad_format = parse_text(R"({"op": "destroy", "id": "nothex"})");
    CHECK_FALSE(decode_command(bad_format, &error).has_value());
    CHECK_FALSE(error.empty());

    // Trop d'hexadécimal et identifiant numérique : refus (spec : hexadécimal, jamais nombre).
    const nlohmann::json too_long = parse_text(R"({"op": "destroy", "id": "00000000deadbeef01"})");
    CHECK_FALSE(decode_command(too_long).has_value());
    const nlohmann::json numeric = parse_text(R"({"op": "destroy", "id": 7})");
    CHECK_FALSE(decode_command(numeric).has_value());
}

TEST_CASE("Wire : refus des tableaux de mauvaise longueur")
{
    // position à 2 composantes, rotation à 5, size à 3, color à 2.
    struct Case {
        const char* text;
    };
    const Case cases[] = {
        {R"({"op": "transform", "id": "1",
           "transform": {"position": [1, 2], "rotation": [0, 0, 0, 1], "scale": [1, 1, 1]}})"},
        {R"({"op": "transform", "id": "1",
           "transform": {"position": [1, 2, 3], "rotation": [0, 0, 0, 1, 1], "scale": [1, 1, 1]}})"},
        {R"({"op": "visual", "id": "1", "visual": {"primitive": "box", "size": [1, 1, 1],
           "color": [0.5, 0.5], "semanticClass": 0}})"},
        {R"({"op": "create", "id": "1", "transform": {"position": [1, 2, 3], "rotation": [0, 0, 0, 1],
           "scale": [1, 1, 1]}, "visual": {"primitive": "box", "size": [1], "color": [1, 1, 1, 1],
           "semanticClass": 0}})"},
    };
    for (const Case& case_entry : cases) {
        std::string error;
        CHECK_FALSE(decode_command(parse_text(case_entry.text), &error).has_value());
        CHECK_FALSE(error.empty());
    }
}

TEST_CASE("Wire : refus des nombres non finis")
{
    std::string error;
    nlohmann::json transform = parse_text(
        R"({"position": [0, 0, 0], "rotation": [0, 0, 0, 1], "scale": [1, 1, 1]})");
    transform["position"] = nlohmann::json::array(
        {1.0, std::numeric_limits<double>::quiet_NaN(), 3.0});
    CHECK_FALSE(decode_command(nlohmann::json{{"op", "transform"}, {"id", "1"}, {"transform", transform}}, &error)
                    .has_value());
    CHECK(error.find("fini") != std::string::npos);

    transform["position"] = nlohmann::json::array(
        {1.0, std::numeric_limits<double>::infinity(), 3.0});
    CHECK_FALSE(decode_command(nlohmann::json{{"op", "transform"}, {"id", "1"}, {"transform", transform}}).has_value());

    // Depuis un texte : nlohmann/json refuse déjà un nombre hors limites (1e999) à la lecture.
    const nlohmann::json from_text = parse_text(
        R"({"op": "camera", "camera": {"transform": {"position": [0, 0, 1e999], "rotation": [0, 0, 0, 1],
           "scale": [1, 1, 1]}, "verticalFovDeg": 60, "near": 0.1, "far": 100}})");
    CHECK_FALSE(from_text.is_object());
    CHECK_FALSE(decode_command(from_text).has_value());
}

TEST_CASE("Wire : refus d'une primitive et d'un op inconnus")
{
    std::string error;
    const nlohmann::json bad_primitive = parse_text(
        R"({"op": "visual", "id": "1", "visual": {"primitive": "torus", "size": [1, 1, 1],
           "color": [1, 1, 1, 1], "semanticClass": 0}})");
    CHECK_FALSE(decode_command(bad_primitive, &error).has_value());
    CHECK(error.find("primitive") != std::string::npos);

    error.clear();
    const nlohmann::json bad_op = parse_text(R"({"op": "rotate", "id": "1"})");
    CHECK_FALSE(decode_command(bad_op, &error).has_value());
    CHECK(error.find("op") != std::string::npos);
}

TEST_CASE("Wire : refus d'un champ manquant et d'un mauvais type")
{
    // Champs manquants.
    for (const char* text : {R"({"id": "1", "visual": {"primitive": "box", "size": [1, 1, 1],
                              "color": [1, 1, 1, 1], "semanticClass": 0}})",
                             R"({"op": "create", "id": "1"})",
                             R"({"op": "create", "id": "1", "transform": {"position": [1, 2, 3],
                                "rotation": [0, 0, 0, 1], "scale": [1, 1, 1]}})",
                             R"({"op": "camera"})"}) {
        std::string error;
        CHECK_FALSE(decode_command(parse_text(text), &error).has_value());
        CHECK_FALSE(error.empty());
    }

    // Mauvais types : visual non objet, scale non tableau, semanticClass non entier ou hors 32 bits.
    for (const char* text : {R"({"op": "visual", "id": "1", "visual": 3})",
                             R"({"op": "transform", "id": "1", "transform": {"position": [1, 2, 3],
                                "rotation": [0, 0, 0, 1], "scale": [1, 1]}})",
                             R"({"op": "visual", "id": "1", "visual": {"primitive": "box", "size": [1, 1, 1],
                                "color": [1, 1, 1, 1], "semanticClass": 1.5}})",
                             R"({"op": "visual", "id": "1", "visual": {"primitive": "box", "size": [1, 1, 1],
                                "color": [1, 1, 1, 1], "semanticClass": -1}})",
                             R"({"op": "visual", "id": "1", "visual": {"primitive": "box", "size": [1, 1, 1],
                                "color": [1, 1, 1, 1], "semanticClass": 4294967296}})"}) {
        CHECK_FALSE(decode_command(parse_text(text)).has_value());
    }

    // Enveloppe du delta : valeur non hexadécimale, full non booléen, champ manquant.
    for (const char* text : {R"({"worldVersion": 1, "tick": "1", "full": false, "sentAtUs": "2", "commands": []})",
                             R"({"worldVersion": "1", "tick": "1", "full": "o", "sentAtUs": "2", "commands": []})",
                             R"({"tick": "1", "full": false, "sentAtUs": "2", "commands": []})",
                             R"({"worldVersion": "1", "tick": "1", "full": true, "sentAtUs": "2"})"}) {
        std::string error;
        CHECK_FALSE(decode_scene_delta(parse_text(text), &error).has_value());
        CHECK_FALSE(error.empty());
    }

    // La commande encodée n'est pas un tableau de commandes, pas plus qu'un objet nu.
    CHECK_FALSE(decode_commands(nlohmann::json{"not", "an", "array"}).has_value());
    CHECK_FALSE(decode_command(nlohmann::json::array()).has_value());
    CHECK_FALSE(decode_scene_delta(nlohmann::json::array()).has_value());

    // Une entrée malveillante malfomée ne lève pas : parse sans exception puis rejet.
    CHECK(parse_text("{ no json").is_discarded());
    CHECK_FALSE(decode_commands(parse_text("{ no json")).has_value());
}

TEST_CASE("Wire : refus d'un tampon inconnu dans les capacités")
{
    std::string error;
    const nlohmann::json caps = parse_text(
        R"({"engineName": "godot", "engineVersion": "4.3", "buffers": ["color", "normals"],
           "windowed": true, "headless": true})");
    REQUIRE(decode_capabilities(caps, &error).has_value());

    error.clear();
    const nlohmann::json bad_caps = parse_text(
        R"({"engineName": "godot", "engineVersion": "4.3", "buffers": ["color", "godot_power"],
           "windowed": true, "headless": true})");
    CHECK_FALSE(decode_capabilities(bad_caps, &error).has_value());
    CHECK(error.find("tampon") != std::string::npos);

    // Mauvais type et champ manquant.
    CHECK_FALSE(decode_capabilities(nlohmann::json{{"engineName", 42}}).has_value());
    CHECK_FALSE(decode_capabilities(nlohmann::json::array()).has_value());
}

TEST_CASE("Wire : playerInput des capacités, facultatif au décodage")
{
    const nlohmann::json without = parse_text(
        R"({"engineName": "godot", "engineVersion": "4.7", "buffers": [], "windowed": true, "headless": false})");
    const auto decoded = decode_capabilities(without);
    REQUIRE(decoded.has_value());
    CHECK_FALSE(decoded->player_input);

    EngineCapabilities caps;
    caps.engine_name = "godot";
    caps.player_input = true;
    const auto round_trip = decode_capabilities(encode_capabilities(caps));
    REQUIRE(round_trip.has_value());
    CHECK(round_trip->player_input);

    nlohmann::json bad = encode_capabilities(caps);
    bad["playerInput"] = 1;
    CHECK_FALSE(decode_capabilities(bad).has_value());
}

TEST_CASE("Wire : render/input fait l'aller-retour, bornes comprises")
{
    PlayerInputMessage message;
    message.input = PlayerInput{0xFFFFFFFFu, axis_max, -axis_max};
    message.captured_at_us = 0x123456789ULL;
    const nlohmann::json encoded = encode_player_input(message);
    CHECK(encoded["capturedAtUs"] == "0000000123456789");
    std::string error;
    const auto decoded = decode_player_input(encoded, &error);
    REQUIRE_MESSAGE(decoded.has_value(), error);
    CHECK(decoded->input == message.input);
    CHECK(decoded->captured_at_us == message.captured_at_us);
}

TEST_CASE("Wire : refus d'un render/input hors bornes ou mal typé")
{
    const auto payload = [](nlohmann::json buttons, nlohmann::json x, nlohmann::json y) {
        return nlohmann::json{{"buttons", std::move(buttons)}, {"moveX", std::move(x)}, {"moveY", std::move(y)},
                              {"capturedAtUs", "0"}};
    };
    std::string error;
    CHECK(decode_player_input(payload(0, 0, 0)).has_value());
    CHECK_FALSE(decode_player_input(payload(-1, 0, 0), &error).has_value());
    CHECK(error.find("buttons") != std::string::npos);
    CHECK_FALSE(decode_player_input(payload(0x100000000LL, 0, 0)).has_value());
    CHECK_FALSE(decode_player_input(payload(std::numeric_limits<std::uint64_t>::max(), 0, 0)).has_value());
    CHECK_FALSE(decode_player_input(payload(0, 32768, 0)).has_value());
    CHECK_FALSE(decode_player_input(payload(0, 0, -32768)).has_value());
    CHECK_FALSE(decode_player_input(payload(0, 0.5, 0)).has_value());
    CHECK_FALSE(decode_player_input(payload("1", 0, 0)).has_value());

    nlohmann::json no_time = payload(0, 0, 0);
    no_time.erase("capturedAtUs");
    CHECK_FALSE(decode_player_input(no_time).has_value());
    no_time["capturedAtUs"] = "zz";
    CHECK_FALSE(decode_player_input(no_time).has_value());
    CHECK_FALSE(decode_player_input(nlohmann::json::array()).has_value());
}

TEST_CASE("Wire : un delta décodé s'applique à un SceneState sans erreur")
{
    SceneDeltaMessage message;
    message.delta.world_version = 4;
    message.delta.commands = {
        SceneCommand{CreateObject{1ULL, sample_transform(), sample_visual(Primitive::plane)}},
        SceneCommand{SetCamera{sample_camera()}},
    };
    message.tick = 2;
    message.full = false;
    message.sent_at_us = 99;

    std::string error;
    const std::optional<SceneDeltaMessage> decoded = decode_scene_delta(encode_scene_delta(message), &error);
    REQUIRE(decoded.has_value());

    SceneState state;
    CHECK_FALSE(state.apply(decoded->delta).has_value());
    CHECK(state.world_version() == 4);
    REQUIRE(state.objects().size() == 1);
    const auto it = state.objects().find(1);
    REQUIRE(it != state.objects().end());
    CHECK(it->second == ObjectState{sample_transform(), sample_visual(Primitive::plane)});
    REQUIRE(state.camera().has_value());
    CHECK(*state.camera() == sample_camera());
}

TEST_CASE("Wire : décodage d'un exemple conforme au texte de la spec (protocole 0.1 §5)")
{
    const char* text =
        R"json({
            "worldVersion": "0000000000000042",
            "tick": "0000000000000017",
            "full": true,
            "sentAtUs": "00000000000296e6",
            "commands": [
                {
                    "op": "create",
                    "id": "0000000000000001",
                    "transform": {
                        "position": [1.0, 2.0, 3.0],
                        "rotation": [0.0, 0.0, 0.0, 1.0],
                        "scale": [1.0, 1.0, 1.0]
                    },
                    "visual": {
                        "primitive": "box",
                        "size": [1.0, 1.0, 1.0],
                        "color": [0.5, 0.6, 0.7, 1.0],
                        "semanticClass": 2
                    }
                },
                {
                    "op": "camera",
                    "camera": {
                        "transform": {
                            "position": [0.0, 2.0, 5.0],
                            "rotation": [0.0, 0.0, 0.0, 1.0],
                            "scale": [1.0, 1.0, 1.0]
                        },
                        "verticalFovDeg": 70.0,
                        "near": 0.05,
                        "far": 1000.0
                    }
                }
            ]
        })json";

    const nlohmann::json payload = parse_text(text);
    REQUIRE(payload.is_object());

    std::string error;
    const std::optional<SceneDeltaMessage> message = decode_scene_delta(payload, &error);
    REQUIRE(message.has_value());
    CHECK(error.empty());
    CHECK(message->delta.world_version == 0x42ULL);
    CHECK(message->tick == 0x17ULL);
    CHECK(message->full == true);
    CHECK(message->sent_at_us == 0x296e6ULL);
    REQUIRE(message->delta.commands.size() == 2);
    CHECK(message->delta.commands[0] == SceneCommand{CreateObject{1, spec_transform(), spec_visual()}});
    CHECK(message->delta.commands[1] == SceneCommand{SetCamera{spec_camera()}});

    // Ré-encodage : bytes stables, si ce n'est le formatage du codec.
    nlohmann::json reencoded = encode_scene_delta(*message);
    CHECK(reencoded["commands"] == payload["commands"]);
}