// SPDX-License-Identifier: MPL-2.0
//
// Tests d'intégration : un vrai client WebSocket (IXWebSocket) contre le CoreServer et un
// vrai CoreRuntime, en boucle locale (spec 0.2 §3 à §5).
#include "sequa/core/server/protocol.hpp"
#include "sequa/core/server/runtime.hpp"
#include "sequa/core/server/server.hpp"

#include <doctest/doctest.h>
#include <ixwebsocket/IXNetSystem.h>
#include <ixwebsocket/IXWebSocket.h>
#include <nlohmann/json.hpp>

#include <chrono>
#include <condition_variable>
#include <memory>
#include <mutex>
#include <string>
#include <thread>
#include <vector>

using namespace sequa::core::server;
using nlohmann::json;
using namespace std::chrono_literals;

namespace {

constexpr auto timeout = std::chrono::seconds(5);

struct Fixture {
    explicit Fixture(ServerOptions options = {}, CoreRuntimeOptions runtime_options = make_runtime_options())
        : runtime(std::make_unique<CoreRuntime>(runtime_options))
    {
        // IXWebSocket ne rapporte pas le port choisi pour le port 0 : on essaie une plage.
        for (int port = 19100; port < 19200; ++port) {
            options.port = port;
            auto candidate = std::make_unique<CoreServer>(options, *runtime);
            if (candidate->start().empty()) {
                server = std::move(candidate);
                return;
            }
        }
        FAIL("aucun port libre entre 19100 et 19199");
    }

    static CoreRuntimeOptions make_runtime_options()
    {
        CoreRuntimeOptions options;
        options.core_version = "9.9.9-test";
        options.real_time = false;
        options.lease_grace = 100ms;
        options.attach_deadline = 5s;
        return options;
    }

    [[nodiscard]] std::string url(const std::string& query = {}) const
    {
        return "ws://127.0.0.1:" + std::to_string(server->options().port) + "/" + query;
    }

    std::unique_ptr<CoreRuntime> runtime; // survit au serveur (déclaré avant)
    std::unique_ptr<CoreServer> server;
};

class TestClient {
public:
    explicit TestClient(const std::string& url, const ix::WebSocketHttpHeaders& headers = {})
    {
        ix::initNetSystem();
        socket_.setUrl(url);
        socket_.setExtraHeaders(headers);
        socket_.disableAutomaticReconnection();
        socket_.setOnMessageCallback([this](const ix::WebSocketMessagePtr& message) {
            const std::lock_guard lock(mutex_);
            switch (message->type) {
            case ix::WebSocketMessageType::Open:
                open_ = true;
                break;
            case ix::WebSocketMessageType::Message:
                messages_.push_back(message->str);
                break;
            case ix::WebSocketMessageType::Close:
                closed_ = true;
                close_code_ = message->closeInfo.code;
                break;
            case ix::WebSocketMessageType::Error:
                closed_ = true;
                break;
            default:
                break;
            }
            changed_.notify_all();
        });
        socket_.start();
    }

    ~TestClient()
    {
        socket_.stop();
        ix::uninitNetSystem();
    }

    TestClient(const TestClient&) = delete;
    TestClient& operator=(const TestClient&) = delete;

    bool wait_open() { return wait([this] { return open_ || closed_; }) && open_; }
    void send(const std::string& text) { socket_.sendText(text); }
    void stop() { socket_.stop(); }

    std::vector<std::string> wait_messages(std::size_t count)
    {
        wait([this, count] { return messages_.size() >= count || closed_; });
        const std::lock_guard lock(mutex_);
        return messages_;
    }

    // Envoie une requête et attend sa réponse (messages reçus jusqu'ici ignorés).
    json call(const std::string& type, json payload = json::object())
    {
        std::size_t before = 0;
        {
            const std::lock_guard lock(mutex_);
            before = messages_.size();
        }
        send(json{{"v", 1}, {"type", type}, {"id", type}, {"payload", std::move(payload)}}.dump());
        const auto messages = wait_messages(before + 1);
        REQUIRE(messages.size() > before);
        return json::parse(messages[before]);
    }

    bool wait_closed() { return wait([this] { return closed_; }); }

    std::uint16_t close_code()
    {
        const std::lock_guard lock(mutex_);
        return close_code_;
    }

private:
    template <typename Predicate>
    bool wait(Predicate predicate)
    {
        std::unique_lock lock(mutex_);
        return changed_.wait_for(lock, timeout, predicate);
    }

    ix::WebSocket socket_;
    std::mutex mutex_;
    std::condition_variable changed_;
    bool open_ = false;
    bool closed_ = false;
    std::uint16_t close_code_ = 0;
    std::vector<std::string> messages_;
};

json handshake(TestClient& client, const char* who = "sequa-studio-host")
{
    REQUIRE(client.wait_open());
    client.send(encode_hello(protocol_version, who));
    const auto messages = client.wait_messages(1);
    REQUIRE(messages.size() == 1);
    INFO("reponse : " << messages.front());
    const json reply = json::parse(messages.front());
    REQUIRE(reply["type"] == "welcome");
    return reply;
}

} // namespace

TEST_CASE("Serveur : poignee de main 0.3 sur un vrai socket")
{
    Fixture fixture;
    TestClient client(fixture.url());
    const json welcome = handshake(client);
    CHECK(welcome["type"] == "welcome");
    CHECK(welcome["payload"]["coreVersion"] == "9.9.9-test");
    CHECK(welcome["payload"]["protocolVersion"] == "0.3.0");
    CHECK(welcome["payload"]["instanceId"] == fixture.runtime->core_status().instance_id);
}

TEST_CASE("Serveur : jeton exige")
{
    ServerOptions options;
    options.token = "0123456789abcdef";
    Fixture fixture(options);

    SUBCASE("absent")
    {
        TestClient client(fixture.url());
        const auto messages = client.wait_messages(1);
        REQUIRE_FALSE(messages.empty());
        CHECK(json::parse(messages.front())["payload"]["code"] == "unauthorized");
        REQUIRE(client.wait_closed());
        CHECK(client.close_code() == close_code::policy_violation);
    }
    SUBCASE("faux")
    {
        TestClient client(fixture.url("?token=0123456789abcdeX"));
        REQUIRE(client.wait_closed());
        CHECK(client.close_code() == close_code::policy_violation);
    }
    SUBCASE("correct, parmi d'autres parametres")
    {
        TestClient client(fixture.url("?x=1&token=0123456789abcdef"));
        CHECK(handshake(client)["type"] == "welcome");
    }
}

TEST_CASE("Serveur : origine verifiee, origine absente acceptee")
{
    SUBCASE("origine locale par defaut")
    {
        Fixture fixture;
        TestClient local(fixture.url(), {{"Origin", "http://localhost:5173"}});
        CHECK(handshake(local, "sequa-studio")["type"] == "welcome");
    }
    SUBCASE("site etranger refuse")
    {
        Fixture fixture;
        TestClient foreign(fixture.url(), {{"Origin", "https://exemple.com"}});
        const auto messages = foreign.wait_messages(1);
        REQUIRE_FALSE(messages.empty());
        CHECK(json::parse(messages.front())["payload"]["code"] == "forbidden-origin");
        REQUIRE(foreign.wait_closed());
        CHECK(foreign.close_code() == close_code::policy_violation);
    }
    SUBCASE("liste explicite : seule l'origine exacte passe")
    {
        ServerOptions options;
        options.allowed_origins = {"http://127.0.0.1:9180"};
        Fixture fixture(options);
        TestClient other_port(fixture.url(), {{"Origin", "http://127.0.0.1:5173"}});
        REQUIRE(other_port.wait_closed());
        TestClient exact(fixture.url(), {{"Origin", "http://127.0.0.1:9180"}});
        CHECK(handshake(exact, "sequa-studio")["type"] == "welcome");
    }
    SUBCASE("client natif ws:// accepte meme avec une liste explicite")
    {
        ServerOptions options;
        options.allowed_origins = {"http://127.0.0.1:9180"};
        Fixture fixture(options);
        TestClient native(fixture.url(), {{"Origin", "ws://127.0.0.1:1234"}});
        CHECK(handshake(native)["type"] == "welcome");
    }
    SUBCASE("piege de prefixe")
    {
        Fixture fixture;
        TestClient trap(fixture.url(), {{"Origin", "http://localhost.exemple.com"}});
        REQUIRE(trap.wait_closed());
        CHECK(trap.close_code() == close_code::policy_violation);
    }
}

TEST_CASE("Serveur : export puis import d'une session par le protocole")
{
    Fixture fixture;
    TestClient client(fixture.url());
    handshake(client);
    CHECK(client.call("session/start", {{"seed", "2026"}})["payload"]["tick"] == 0);
    CHECK(client.call("session/input", {{"buttons", 1}, {"moveX", 32767}, {"moveY", 0}})["payload"]["tick"] == 0);
    // Pas de temps réel ici : la session n'avance pas toute seule, l'export est à tick 0.
    const json exported = client.call("session/export", {{"includeHashes", true}})["payload"];
    CHECK(exported["tick"] == 0);
    const json imported = client.call("session/import", {{"recording", exported["recording"]}, {"resume", false}})["payload"];
    CHECK(imported["running"] == false);
    CHECK(imported["stateHash"] == exported["stateHash"]);
    CHECK(client.call("session/import", {{"recording", "@@@@"}, {"resume", true}})["payload"]["code"] == "invalid-recording");
}

TEST_CASE("Serveur : bail - la deconnexion du controleur declenche l'arret")
{
    auto runtime_options = Fixture::make_runtime_options();
    runtime_options.linked = true;
    Fixture fixture({}, runtime_options);
    {
        TestClient controller(fixture.url());
        handshake(controller);
        CHECK(controller.call("core/attach")["payload"]["linked"] == true);
        CHECK(fixture.runtime->core_status().controller_attached);
        controller.stop();
    }
    std::this_thread::sleep_for(300ms); // grâce de 100 ms
    CHECK(fixture.runtime->exit_reason() == CoreRuntime::ExitReason::lease_expired);
}

TEST_CASE("Serveur : bail leve par core/detach - pas d'arret")
{
    auto runtime_options = Fixture::make_runtime_options();
    runtime_options.linked = true;
    Fixture fixture({}, runtime_options);
    {
        TestClient controller(fixture.url());
        handshake(controller);
        CHECK(controller.call("core/attach")["payload"]["linked"] == true);
        CHECK(controller.call("core/detach")["payload"]["linked"] == false);
        controller.stop();
    }
    std::this_thread::sleep_for(300ms);
    CHECK(fixture.runtime->exit_reason() == CoreRuntime::ExitReason::none);
}

TEST_CASE("Serveur : core/shutdown demande l'arret")
{
    Fixture fixture;
    TestClient client(fixture.url());
    handshake(client);
    CHECK(client.call("core/shutdown")["type"] == "core/shutdown");
    std::this_thread::sleep_for(400ms);
    CHECK(fixture.runtime->exit_reason() == CoreRuntime::ExitReason::shutdown);
}

TEST_CASE("Serveur : port deja occupe -> start() renvoie une erreur")
{
    Fixture first;
    ServerOptions options;
    options.port = first.server->options().port;
    CoreServer second(options, *first.runtime);
    CHECK_FALSE(second.start().empty());
    CHECK_FALSE(second.running());
}