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

#include <arpa/inet.h>
#include <ifaddrs.h>
#include <net/if.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);
}

// 动态获取指定网卡 IPv4 地址
std::string get_ip_address(const std::string& ifname)
{
    struct ifaddrs *ifaddr, *ifa;
    char ip[INET_ADDRSTRLEN] = {0};

    if (getifaddrs(&ifaddr) == -1)
    {
        perror("getifaddrs");
        return "";
    }

    for (ifa = ifaddr; ifa != nullptr; ifa = ifa->ifa_next)
    {
        if (ifa->ifa_addr == nullptr) continue;

        if (ifa->ifa_addr->sa_family == AF_INET && ifname == ifa->ifa_name)
        {
            void* addr = &((struct sockaddr_in*)ifa->ifa_addr)->sin_addr;
            if (inet_ntop(AF_INET, addr, ip, sizeof(ip)))
            {
                freeifaddrs(ifaddr);
                return ip;
            }
        }
    }

    freeifaddrs(ifaddr);
    return "";
}

// ========== 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 ==========
GstElement* RTMPManager::create_pipeline(const Camera& cam)
{
    const int width = cam.width;
    const int height = cam.height;
    const int fps = cam.fps;
    const int bitrate = cam.bitrate;

    const std::string stream_name = cam.name + "_main";
    const std::string app = "camera";
    // 两个不同的 SRS 实例：live 用于远控，record 用于录像
    const std::string live_rtmp = "rtmp://127.0.0.1:1935/" + app + "/" + stream_name + "?vhost=live";
    const std::string record_rtmp = "rtmp://127.0.0.1:2935/" + app + "/" + stream_name + "?vhost=record";

    // 双路推流管线：一份流编码后 tee 分支分别送往两个 flvmux+rtmpsink
    std::string pipeline_str =
        "v4l2src name=src device=" + cam.device +
        " ! "
        "video/x-raw,format=NV12,width=" +
        std::to_string(width) + ",height=" + std::to_string(height) + ",framerate=" + std::to_string(fps) +
        "/1 ! "
        "mpph264enc bps=" +
        std::to_string(bitrate) + " gop=" + std::to_string(fps) +
        " rc-mode=cbr ! "
        "h264parse ! tee name=t "

        // --- 分支1：低延时远控 SRS ---
        "t. ! queue max-size-buffers=5 leaky=downstream ! "
        "flvmux streamable=true name=mux_live "
        "audiotestsrc wave=silence ! audioconvert ! audioresample ! voaacenc ! aacparse ! mux_live. "
        "mux_live. ! rtmpsink location=\"" +
        live_rtmp +
        "\" sync=false async=false "

        // --- 分支2：录像 SRS ---
        "t. ! queue max-size-buffers=5 leaky=downstream ! "
        "flvmux streamable=true name=mux_record "
        "audiotestsrc wave=silence ! audioconvert ! audioresample ! voaacenc ! aacparse ! mux_record. "
        "mux_record. ! rtmpsink location=\"" +
        record_rtmp +
        "\" sync=false async=false "

        // --- 可选第三分支：AI/检测 ---
        "t. ! queue ! fakesink sync=false";

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

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

    while (ctx->running)
    {
        // 1. 检查设备节点是否存在
        struct stat st{};
        if (stat(cam.device.c_str(), &st) != 0)
        {
            ctx->status.running = false;
            ctx->status.last_error = "Device not found: " + cam.device;
            LOG_WARN("[RTMP] " + key + " - " + ctx->status.last_error);
            std::this_thread::sleep_for(std::chrono::seconds(3));
            continue;
        }

        // 2. 创建 GStreamer 管线
        GstElement* pipeline = create_pipeline(cam);
        if (!pipeline)
        {
            ctx->status.running = false;
            ctx->status.last_error = "Pipeline creation failed";
            std::this_thread::sleep_for(std::chrono::seconds(3));
            continue;
        }
        gst_element_set_name(pipeline, key.c_str());
        GstBus* bus = gst_element_get_bus(pipeline);

        // 3. 在 v4l2src 的 src pad 上挂探测 probe
        bool got_frame = false;
        {
            GstElement* src = gst_bin_get_by_name(GST_BIN(pipeline), "src");
            if (src)
            {
                GstPad* pad = gst_element_get_static_pad(src, "src");
                if (pad)
                {
                    gst_pad_add_probe(
                        pad, GST_PAD_PROBE_TYPE_BUFFER,
                        [](GstPad*, GstPadProbeInfo*, gpointer user_data) -> GstPadProbeReturn
                        {
                            *static_cast<bool*>(user_data) = true;
                            return GST_PAD_PROBE_OK;
                        },
                        &got_frame, nullptr);
                    gst_object_unref(pad);
                }
                else
                {
                    LOG_WARN("[RTMP] " + key + " - src has no 'src' pad?");
                }
                gst_object_unref(src);
            }
            else
            {
                LOG_WARN("[RTMP] " + key + " - cannot find element 'src' for pad-probe");
            }
        }

        // 4. 启动播放
        LOG_INFO("[RTMP] Starting stream: " + key);
        gst_element_set_state(pipeline, GST_STATE_PLAYING);

        // 等待进入 PLAYING 状态（最长 5s）
        GstState state = GST_STATE_NULL, pending = GST_STATE_NULL;
        bool confirmed_running = false;
        if (gst_element_get_state(pipeline, &state, &pending, 5 * GST_SECOND) == GST_STATE_CHANGE_SUCCESS &&
            state == GST_STATE_PLAYING)
        {
            confirmed_running = true;
            ctx->status.running = true;
            ctx->status.last_error.clear();
            LOG_INFO("[RTMP] " + key + " confirmed PLAYING");
        }
        else
        {
            ctx->status.running = false;
            ctx->status.last_error = "Pipeline failed to confirm PLAYING";
            LOG_WARN("[RTMP] " + key + " - " + ctx->status.last_error);
        }

        if (!confirmed_running)
        {
            gst_element_set_state(pipeline, GST_STATE_NULL);
            if (bus) gst_object_unref(bus);
            gst_object_unref(pipeline);
            std::this_thread::sleep_for(std::chrono::milliseconds(RETRY_BASE_DELAY_MS));
            continue;
        }

        // 5. 运行阶段：监测帧和错误
        const auto start_t = std::chrono::steady_clock::now();
        bool need_restart = false;

        while (ctx->running)
        {
            // 检查是否收到帧（前 5s 内）
            if (!got_frame)
            {
                auto elapsed =
                    std::chrono::duration_cast<std::chrono::seconds>(std::chrono::steady_clock::now() - start_t)
                        .count();
                if (elapsed > 5)
                {
                    ctx->status.running = false;
                    ctx->status.last_error = "No frames detected (no video signal)";
                    LOG_ERROR("[RTMP] " + key + " - " + ctx->status.last_error);
                    need_restart = true;
                    break;
                }
            }
            else
            {
                ctx->status.running = true;
                ctx->status.last_error.clear();
            }

            // 等待错误或 EOS 消息
            GstMessage* msg = gst_bus_timed_pop_filtered(bus, 200 * GST_MSECOND,
                                                         (GstMessageType)(GST_MESSAGE_ERROR | GST_MESSAGE_EOS));

            if (!msg) continue;

            switch (GST_MESSAGE_TYPE(msg))
            {
                case GST_MESSAGE_ERROR:
                {
                    GError* err = nullptr;
                    gst_message_parse_error(msg, &err, nullptr);
                    ctx->status.running = false;
                    ctx->status.last_error = err ? err->message : "GStreamer error";
                    LOG_ERROR("[RTMP] " + key + " stream error: " + ctx->status.last_error);
                    if (err) g_error_free(err);
                    need_restart = true;
                    break;
                }
                case GST_MESSAGE_EOS:
                    ctx->status.running = false;
                    ctx->status.last_error = "End of stream (EOS)";
                    LOG_WARN("[RTMP] " + key + " reached EOS");
                    need_restart = true;
                    break;
                default:
                    break;
            }
            gst_message_unref(msg);

            if (need_restart) break;
        }

        // 6. 收尾清理
        gst_element_set_state(pipeline, GST_STATE_NULL);
        if (bus) gst_object_unref(bus);
        gst_object_unref(pipeline);

        // 7. 若仍在运行状态，准备重启
        if (ctx->running)
        {
            LOG_WARN("[RTMP] Restarting " + key + " in 3s...");
            std::this_thread::sleep_for(std::chrono::milliseconds(RETRY_BASE_DELAY_MS));
        }
    }

    ctx->status.running = false;
    LOG_INFO("[RTMP] Stream thread exited for " + key);
}

// ========== 启停与状态 ==========
void RTMPManager::start_all()
{
    LOG_INFO("[RTMP] Starting all record streams...");
    std::lock_guard<std::mutex> lock(streams_mutex);

    int delay_ms = 0;
    for (auto& cam : g_app_config.cameras)
    {
        auto key = make_key(cam.name);
        if (streams.find(key) != streams.end())
        {
            LOG_INFO("[RTMP] Stream already running: " + key);
            continue;
        }

        auto ctx = std::make_unique<StreamContext>();
        ctx->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;  // 每路错开 200ms
    }
}

void RTMPManager::stop_all()
{
    std::lock_guard<std::mutex> lock(streams_mutex);
    for (auto& kv : streams) kv.second->running.store(false);
    for (auto& kv : streams)
        if (kv.second->thread.joinable()) kv.second->thread.join();
    streams.clear();
}

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));
    return (it != streams.end() && 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 + ":1985/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];
        auto key = make_key(cam.name);

        ChannelInfo ch;
        ch.loc = static_cast<int>(i);
        ch.url.clear();
        ch.running = false;
        ch.reason = "Not started";

        auto it = streams.find(key);
        if (it != streams.end())
        {
            auto& status = it->second->status;
            ch.running = status.running;
            if (status.running)
            {
                ch.url = get_stream_url(cam.name);
                ch.reason.clear();
            }
            else
            {
                ch.reason = status.last_error.empty() ? "Unknown error" : status.last_error;
            }
        }
        else
        {
            ch.reason = "Context missing";
        }

        result.push_back(ch);
    }
    return result;
}
