// utun_node.cpp — embedded uTun node running in a dedicated thread
#include "utun_node.h"
#include <cinttypes>

// === C headers ===
extern "C" {
#include "utun_instance.h"
#include "etcp_router.h"
#include "etcp_api.h"
#include "etcp.h"
#include "config_parser.h"
#include "config_updater.h"
#include "control_server.h"
#include "secure_channel.h"
#include "../lib/u_async.h"
#include "../lib/ll_queue.h"
#include "../lib/memory_pool.h"
#include "../lib/debug_config.h"
#include "../lib/mem.h"
#include "chat_sync.h"
#include "chat_core.h"
#include "gui_bridge.h"
}

#define ETCP_RT_ID_CHAT  0x11

static thread_local UtunNode* g_currentNode = nullptr;

UtunNode::UtunNode(QObject* parent) : QObject(parent) {}

UtunNode::~UtunNode() {
    stop();
}

bool UtunNode::start(const QString& configPath) {
    if (m_running) return false;
    m_configPath = configPath;
    m_stop = false;
    m_running = true;
    m_thread = std::thread(&UtunNode::runLoop, this);

    for (int i = 0; i < 50 && m_running && !m_instance; ++i)
        std::this_thread::sleep_for(std::chrono::milliseconds(10));

    if (!m_instance) {
        m_stop = true;
        if (m_thread.joinable()) m_thread.join();
        m_running = false;
        return false;
    }
    emit started();
    return true;
}

void UtunNode::setDebugFile(const QString& path) {
    m_debugFile = path;
}

void UtunNode::setDbPath(const QString& path) {
    m_dbPath = path;
}

void UtunNode::stop() {
    if (!m_running) return;
    m_stop = true;
    if (m_thread.joinable()) m_thread.join();
    m_running = false;
}

void UtunNode::send(uint64_t dstNodeId, const QByteArray& data) {
    if (!m_instance) return;
    struct ll_entry* entry = queue_entry_new(data.size());
    if (!entry) return;
    memcpy(entry->data, data.constData(), data.size());
    etcp_route_send(m_instance, dstNodeId, entry, 0);
}

QString UtunNode::nodeIdHex() const {
    if (!m_instance) return {};
    char buf[32];
    snprintf(buf, sizeof(buf), "%016" PRIx64, m_instance->node_id);
    return QString(buf);
}

QString UtunNode::pubKeyHex() const {
    if (!m_instance || !m_instance->config) return {};
    return QString::fromLatin1(m_instance->config->global.my_public_key_hex, 64);
}

void UtunNode::recvCallback(struct ETCP_CONN* conn, struct ll_entry* entry) {
    if (!g_currentNode || !entry) return;
    uint64_t src = conn ? conn->peer_node_id : 0;
    QByteArray data((const char*)entry->data, (int)(entry->len ? entry->len : 0));
    QMetaObject::invokeMethod(g_currentNode, [=] {
        emit g_currentNode->messageReceived(src, data);
    }, Qt::QueuedConnection);
}

void UtunNode::runLoop() {
    g_currentNode = this;

    debug_config_init();
    debug_set_level(DEBUG_LEVEL_ERROR);
    debug_enable_function_name(0);

    if (!m_debugFile.isEmpty()) {
        debug_enable_file_output(m_debugFile.toUtf8().constData(), 0);
        g_debug_config.thread_marker = 2;
    }

    utun_instance_set_tun_init_enabled(0);

    struct UASYNC* ua = uasync_create();
    if (!ua) {
        QMetaObject::invokeMethod(this, [this] { emit error("uasync_create failed"); });
        g_currentNode = nullptr;
        return;
    }

    m_instance = utun_instance_create(ua, m_configPath.toUtf8().constData());
    if (!m_instance) {
        QMetaObject::invokeMethod(this, [this] { emit error("utun_instance_create failed"); });
        uasync_destroy(ua, 0);
        g_currentNode = nullptr;
        return;
    }

    m_instance->test_user_ptr = this;

    /* set ua for gui_bridge before init, so GUI can post */
    gui_bridge_set_uasync(ua);

    if (utun_instance_init(m_instance) != 0) {
        QMetaObject::invokeMethod(this, [this] { emit error("utun_instance_init failed"); });
        utun_instance_destroy(m_instance);
        m_instance = nullptr;
        uasync_destroy(ua, 0);
        g_currentNode = nullptr;
        return;
    }

    etcp_router_bind(m_instance, ETCP_RT_ID_CHAT, recvCallback);

    /* Initialize chat_core (DB) and chat_sync */
    chat_core_init(m_instance, m_dbPath.toUtf8().constData());
    chat_sync_init(m_instance, NULL);
    DEBUG_INFO(DEBUG_CATEGORY_DEBUG, "chat_core + chat_sync initialized");

    while (!m_stop) {
        uasync_poll(ua, 100);
    }

    etcp_router_bind(m_instance, ETCP_RT_ID_CHAT, nullptr);
    chat_sync_destroy(m_instance);
    chat_core_destroy(m_instance);
    utun_instance_destroy(m_instance);
    m_instance = nullptr;
    uasync_destroy(ua, 0);
    g_currentNode = nullptr;
    QMetaObject::invokeMethod(this, [this] { emit stopped(); });
}