// rtmp_manager.cpp
#include "rtmp_manager.hpp"

#include <arpa/inet.h>
#include <ifaddrs.h>
#include <netinet/in.h>
#include <sys/stat.h>

#include <chrono>
#include <cstring>
#include <thread>

// =======================================================
// 工具函数
// =======================================================
static bool device_exists(const std::string& path)
{
    struct stat st;
    return stat(path.c_str(), &st) == 0;
}

// 获取指定网卡 IPv4
std::string get_ip_address(const std::string& ifname)
{
    struct ifaddrs* ifaddr = nullptr;
    if (getifaddrs(&ifaddr) != 0) return "";

    char ip[INET_ADDRSTRLEN] = {0};
    for (auto* ifa = ifaddr; ifa; ifa = ifa->ifa_next)
    {
        if (!ifa->ifa_addr) continue;
        if (ifa->ifa_addr->sa_family == AF_INET && ifname == ifa->ifa_name)
        {
            auto* addr = &reinterpret_cast<sockaddr_in*>(ifa->ifa_addr)->sin_addr;
            inet_ntop(AF_INET, addr, ip, sizeof(ip));
            break;
        }
    }

    freeifaddrs(ifaddr);
    return ip;
}

// =======================================================
// 静态成员
// =======================================================
std::unordered_map<std::string, std::unique_ptr<RTMPManager::StreamContext>> RTMPManager::streams;
std::mutex RTMPManager::streams_mutex;

// =======================================================
// 初始化
// =======================================================
void RTMPManager::init()
{
    gst_init(nullptr, nullptr);
    LOG_INFO("[RTMP] GStreamer initialized");
}

std::string RTMPManager::make_key(const std::string& name) { return name + "_main"; }

// =======================================================
// 创建推流管线（稳定版）
// =======================================================
GstElement* RTMPManager::create_pipeline(const Camera& cam)
{
    const std::string stream = cam.name + "_main";
    const std::string app = "camera";

    const std::string live_rtmp = "rtmp://36.153.162.171:19435/" + app + "/" + stream + "?vhost=live";

    std::string pipeline_str = "v4l2src name=src device=" + cam.device +
                               " io-mode=dmabuf "

                               "! video/x-raw,format=NV12,"
                               "width=" +
                               std::to_string(cam.width) + ",height=" + std::to_string(cam.height) +
                               ",framerate=" + std::to_string(cam.fps) +
                               "/1 "

                               // 🔻 队列深度压到 2 帧（≈ 60ms@30fps）
                               "! queue max-size-buffers=2 max-size-time=0 leaky=downstream "

                               // 🔻 编码器：baseline + CBR + 无 B 帧
                               "! mpph264enc "
                               "rc-mode=cbr "
                               "bps=" +
                               std::to_string(cam.bitrate) +
                               " "
                               "gop=" +
                               std::to_string(cam.fps) +
                               " "
                               "header-mode=each-idr "
                               "profile=baseline "

                               // SPS/PPS 每秒刷新一次（SRS/WebRTC 友好）
                               "! h264parse config-interval=1 "

                               // 🔻 时间戳整形但不强行等待
                               "! identity sync=false single-segment=true "

                               // FLV 最小缓存模式
                               "! flvmux streamable=true "

                               // sink 本身不参与同步
                               "! rtmpsink location=\"" +
                               live_rtmp +
                               "\" "
                               "sync=false async=false";

    GError* error = nullptr;
    GstElement* pipeline = gst_parse_launch(pipeline_str.c_str(), &error);
    if (error)
    {
        LOG_ERROR("[RTMP] Pipeline creation failed: " + std::string(error->message));
        g_error_free(error);
        return nullptr;
    }

    return pipeline;
}

// =======================================================
// 主推流线程
// =======================================================
void RTMPManager::stream_loop(Camera cam, StreamContext* ctx)
{
    const std::string key = make_key(cam.name);

    while (ctx->thread_running)
    {
        // 1. 设备存在性
        if (!device_exists(cam.device))
        {
            {
                std::lock_guard<std::mutex> lk(ctx->status_mutex);
                ctx->status.running = false;
                ctx->status.last_error = "Device not found: " + cam.device;
            }
            LOG_WARN("[RTMP] " + key + " - device not found");
            std::this_thread::sleep_for(std::chrono::seconds(3));
            continue;
        }

        // 2. 创建 pipeline
        GstElement* pipeline = create_pipeline(cam);
        if (!pipeline)
        {
            {
                std::lock_guard<std::mutex> lk(ctx->status_mutex);
                ctx->status.running = false;
                ctx->status.last_error = "Pipeline creation failed";
            }
            std::this_thread::sleep_for(std::chrono::seconds(3));
            continue;
        }

        GstBus* bus = gst_element_get_bus(pipeline);

        LOG_INFO("[RTMP] Starting stream: " + key);
        gst_element_set_state(pipeline, GST_STATE_PLAYING);

        // 3. 等待进入 PLAYING
        GstState state = GST_STATE_NULL;
        if (gst_element_get_state(pipeline, &state, nullptr, 5 * GST_SECOND) == GST_STATE_CHANGE_SUCCESS &&
            state == GST_STATE_PLAYING)
        {
            std::lock_guard<std::mutex> lk(ctx->status_mutex);
            ctx->status.running = true;
            ctx->status.last_error.clear();
            LOG_INFO("[RTMP] " + key + " confirmed PLAYING");
        }
        else
        {
            std::lock_guard<std::mutex> lk(ctx->status_mutex);
            ctx->status.running = false;
            ctx->status.last_error = "Failed to reach PLAYING";
            LOG_ERROR("[RTMP] " + key + " failed to PLAY");
            goto cleanup;
        }

        // 4. 正常运行：只监听 ERROR / EOS
        while (ctx->thread_running)
        {
            GstMessage* msg = gst_bus_timed_pop_filtered(
                bus, 300 * GST_MSECOND, static_cast<GstMessageType>(GST_MESSAGE_ERROR | GST_MESSAGE_EOS));

            if (!msg)
            {
                // 心跳：pipeline 没死就认为在跑
                std::lock_guard<std::mutex> lk(ctx->status_mutex);
                ctx->status.running = true;
                continue;
            }

            if (GST_MESSAGE_TYPE(msg) == GST_MESSAGE_ERROR)
            {
                GError* err = nullptr;
                gst_message_parse_error(msg, &err, nullptr);

                {
                    std::lock_guard<std::mutex> lk(ctx->status_mutex);
                    ctx->status.running = false;
                    ctx->status.last_error = err ? err->message : "Unknown GStreamer error";
                }

                LOG_ERROR("[RTMP] " + key + " ERROR: " + (err ? err->message : "unknown"));
                if (err) g_error_free(err);
                gst_message_unref(msg);
                break;
            }

            if (GST_MESSAGE_TYPE(msg) == GST_MESSAGE_EOS)
            {
                {
                    std::lock_guard<std::mutex> lk(ctx->status_mutex);
                    ctx->status.running = false;
                    ctx->status.last_error = "EOS";
                }
                LOG_WARN("[RTMP] " + key + " EOS");
                gst_message_unref(msg);
                break;
            }

            gst_message_unref(msg);
        }

    cleanup:
        gst_element_set_state(pipeline, GST_STATE_NULL);
        if (bus) gst_object_unref(bus);
        gst_object_unref(pipeline);

        if (ctx->thread_running)
        {
            LOG_WARN("[RTMP] Restarting " + key + " in 3s...");
            std::this_thread::sleep_for(std::chrono::seconds(3));
        }
    }

    {
        std::lock_guard<std::mutex> lk(ctx->status_mutex);
        ctx->status.running = false;
    }
    LOG_INFO("[RTMP] Stream thread exited for " + key);
}

// =======================================================
// 启停管理
// =======================================================
void RTMPManager::start_all()
{
    LOG_INFO("[RTMP] Starting enabled streams...");
    std::lock_guard<std::mutex> lock(streams_mutex);

    int delay_ms = 0;
    for (const auto& cam : g_app_config.cameras)
    {
        if (!cam.enabled)
        {
            LOG_INFO("[RTMP] Skip disabled camera: " + cam.name);
            continue;
        }

        const auto key = make_key(cam.name);
        if (streams.count(key)) continue;

        auto ctx = std::make_unique<StreamContext>();
        ctx->thread_running.store(true);

        ctx->thread = std::thread(
            [cam, ptr = ctx.get(), delay_ms]()
            {
                std::this_thread::sleep_for(std::chrono::milliseconds(delay_ms));
                stream_loop(cam, ptr);
            });

        streams.emplace(key, std::move(ctx));
        delay_ms += 200;
    }
}

void RTMPManager::stop_all()
{
    std::lock_guard<std::mutex> lock(streams_mutex);
    for (auto& kv : streams) kv.second->thread_running.store(false);

    for (auto& kv : streams)
        if (kv.second->thread.joinable()) kv.second->thread.join();

    streams.clear();
}

// =======================================================
// 状态 & URL
// =======================================================
bool RTMPManager::is_streaming(const std::string& cam_name)
{
    std::lock_guard<std::mutex> lock(streams_mutex);
    auto it = streams.find(make_key(cam_name));
    if (it == streams.end()) return false;

    std::lock_guard<std::mutex> lk(it->second->status_mutex);
    return it->second->status.running;
}

std::string RTMPManager::get_stream_url(const std::string& cam_name)
{
    std::string ip = get_ip_address("enP2p33s0");
    if (ip.empty()) ip = "127.0.0.1";

    return "http://" + ip + ":11985/rtc/v1/whep/?app=camera&stream=" + cam_name + "_main&vhost=live";
}

// =======================================================
// 汇总状态
// =======================================================
std::vector<RTMPManager::ChannelInfo> RTMPManager::get_all_channels_status()
{
    std::vector<ChannelInfo> result;
    std::lock_guard<std::mutex> lock(streams_mutex);

    for (size_t i = 0; i < g_app_config.cameras.size(); ++i)
    {
        const auto& cam = g_app_config.cameras[i];
        ChannelInfo ch{};
        ch.loc = static_cast<int>(i);

        if (!cam.enabled)
        {
            ch.running = false;
            ch.reason = "Disabled by config";
            result.push_back(ch);
            continue;
        }

        auto it = streams.find(make_key(cam.name));
        if (it != streams.end())
        {
            std::lock_guard<std::mutex> lk(it->second->status_mutex);
            ch.running = it->second->status.running;
            ch.reason = it->second->status.last_error;
            if (ch.running) ch.url = get_stream_url(cam.name);
        }
        else
        {
            ch.running = false;
            ch.reason = "Not started";
        }

        result.push_back(ch);
    }

    return result;
}