// rtsp_manager.cpp
#include "rtmp_manager.hpp"
#include "logger.hpp"
#include <iostream>
#include <chrono>
#include <thread>

std::unordered_map<std::string, RTMPManager::StreamContext> RTMPManager::streams;
std::mutex RTMPManager::streams_mutex;

static inline std::string stream_type_suffix(StreamType type)
{
    return (type == StreamType::MAIN) ? "_main" : "_sub";
}

std::string RTMPManager::make_stream_key(const std::string &cam_name, StreamType type)
{
    return cam_name + stream_type_suffix(type);
}

void RTMPManager::init()
{
    gst_init(nullptr, nullptr);
    LOG_INFO("[RTMP] GStreamer initialized.");
}

GstElement *RTMPManager::create_pipeline(const Camera &cam, StreamType type)
{
    // 拷贝原始参数
    int width = cam.width;
    int height = cam.height;
    int fps = cam.fps;
    int bitrate = cam.bitrate;

    if (type == StreamType::SUB)
    {
        // 简单一刀切策略：分辨率 /2，帧率 /2，码率 /2，临界值保护
        width = std::max(160, width / 2);
        height = std::max(120, height / 2);
        fps = std::max(10, fps / 2);
        bitrate = std::max(300000, bitrate / 2); // 最低 300kbps
    }

    // 构建不同的流名（stream key）
    std::string stream_name = cam.name + (type == StreamType::MAIN ? "_main" : "_sub");

    std::string pipeline_str =
        "v4l2src device=" + cam.device +
        " ! video/x-raw,format=NV12,width=" + std::to_string(width) +
        ",height=" + std::to_string(height) +
        ",framerate=" + std::to_string(fps) + "/1"
                                              " ! queue max-size-buffers=1 leaky=downstream "
                                              " ! mpph264enc bps=" +
        std::to_string(bitrate) +
        " gop=" + std::to_string(fps) +
        " ! h264parse "
        " ! flvmux streamable=true name=mux "
        " ! rtmpsink location=\"rtmp://127.0.0.1/live/" +
        stream_name +
        " live=1\" sync=false";

    LOG_INFO("[RTMP] Creating pipeline for '" + cam.name + "' (" +
             (type == StreamType::MAIN ? "MAIN" : "SUB") + ") -> " + pipeline_str);

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

void RTMPManager::stream_loop(Camera cam, StreamType type)
{
    const std::string key = make_stream_key(cam.name, type);
    LOG_INFO("[RTMP] Stream thread started for '" + key + "'");

    while (true)
    {
        {
            std::lock_guard<std::mutex> lock(streams_mutex);
            if (!streams[key].running)
                break;
        }

        GstElement *pipeline = create_pipeline(cam, type);
        if (!pipeline)
        {
            LOG_ERROR("[RTMP] Failed to create pipeline for '" + key + "', retrying in 3s...");
            std::this_thread::sleep_for(std::chrono::seconds(3));
            continue;
        }

        GstBus *bus = gst_element_get_bus(pipeline);
        gst_element_set_state(pipeline, GST_STATE_PLAYING);
        LOG_INFO("[RTMP] Camera '" + key + "' streaming...");

        bool error_occurred = false;
        // 简单重连计数（可选）：连续失败超过 N 次可以退出
        int consecutive_failures = 0;
        const int MAX_RETRIES = 5;

        while (true)
        {
            GstMessage *msg = gst_bus_timed_pop_filtered(
                bus, GST_CLOCK_TIME_NONE,
                static_cast<GstMessageType>(GST_MESSAGE_ERROR | GST_MESSAGE_EOS));

            {
                std::lock_guard<std::mutex> lock(streams_mutex);
                if (!streams[key].running)
                    break;
            }

            if (!msg)
                continue;

            if (GST_MESSAGE_TYPE(msg) == GST_MESSAGE_ERROR)
            {
                GError *err = nullptr;
                gchar *debug = nullptr;
                gst_message_parse_error(msg, &err, &debug);
                LOG_ERROR("[RTMP] Error on '" + key + "': " + std::string(err->message));
                if (debug)
                    LOG_DEBUG(std::string(debug));
                g_error_free(err);
                g_free(debug);
                error_occurred = true;
                consecutive_failures++;
            }
            else if (GST_MESSAGE_TYPE(msg) == GST_MESSAGE_EOS)
            {
                LOG_WARN("[RTMP] EOS received on '" + key + "'");
                error_occurred = true;
                consecutive_failures++;
            }

            gst_message_unref(msg);
            if (error_occurred)
                break;
        }

        gst_element_set_state(pipeline, GST_STATE_NULL);
        gst_object_unref(pipeline);
        gst_object_unref(bus);

        if (!error_occurred)
            break;

        if (consecutive_failures >= MAX_RETRIES)
        {
            LOG_ERROR("[RTMP] Max retries reached for '" + key + "'. Stopping reconnection attempts.");
            // 可以选择将 running 置为 false，让上层知道失败
            std::lock_guard<std::mutex> lock(streams_mutex);
            streams[key].running = false;
            break;
        }

        LOG_WARN("[RTMP] Reconnecting '" + key + "' in 3s...");
        std::this_thread::sleep_for(std::chrono::seconds(3));
    }

    LOG_INFO("[RTMP] Stream thread exited for '" + key + "'");
}

void RTMPManager::start_camera(const Camera &cam, StreamType type)
{
    std::lock_guard<std::mutex> lock(streams_mutex);
    std::string key = make_stream_key(cam.name, type);
    if (streams.count(key) && streams[key].running)
    {
        LOG_WARN("[RTMP] Camera '" + key + "' already streaming.");
        return;
    }

    StreamContext ctx;
    ctx.running = true;
    ctx.thread = std::thread([cam, type]()
                             { RTMPManager::stream_loop(cam, type); });
    streams[key] = std::move(ctx);
}

void RTMPManager::stop_camera(const std::string &cam_name, StreamType type)
{
    std::lock_guard<std::mutex> lock(streams_mutex);
    std::string key = make_stream_key(cam_name, type);
    auto it = streams.find(key);
    if (it == streams.end())
    {
        LOG_WARN("[RTMP] Camera '" + key + "' not found.");
        return;
    }

    it->second.running = false;
    LOG_INFO("[RTMP] Stopping camera '" + key + "'...");

    if (it->second.thread.joinable())
        it->second.thread.join();

    streams.erase(it);
}

bool RTMPManager::is_streaming(const std::string &cam_name, StreamType type)
{
    std::lock_guard<std::mutex> lock(streams_mutex);
    std::string key = make_stream_key(cam_name, type);
    auto it = streams.find(key);
    return it != streams.end() && it->second.running;
}

bool RTMPManager::is_any_streaming()
{
    std::lock_guard<std::mutex> lock(streams_mutex);
    for (auto &kv : streams)
        if (kv.second.running)
            return true;
    return false;
}

void RTMPManager::stop_all()
{
    std::vector<std::string> names;
    {
        std::lock_guard<std::mutex> lock(streams_mutex);
        for (auto &kv : streams)
            names.push_back(kv.first);
    }

    for (auto &name : names)
    {
        // name 中包含后缀，但是 stop_camera 需要 cam_name + StreamType
        // 我们可以解析后缀，或新增一个 stop_by_key。为简单起见解析：
        if (name.size() > 5 && name.find("_sub") == name.size() - 4)
        {
            std::string cam_name = name.substr(0, name.size() - 4);
            stop_camera(cam_name, StreamType::SUB);
        }
        else if (name.size() > 6 && name.find("_main") == name.size() - 5)
        {
            std::string cam_name = name.substr(0, name.size() - 5);
            stop_camera(cam_name, StreamType::MAIN);
        }
        else
        {
            // fallback: stop by treating as MAIN
            stop_camera(name, StreamType::MAIN);
        }
    }
}

std::string RTMPManager::get_stream_url(const std::string &cam_name, StreamType type)
{
    // 根据你本地 RTMP 服务地址组装 URL，和 create_pipeline 的 stream_name 保持一致
    std::string stream_name = cam_name + stream_type_suffix(type);
    return std::string("rtmp://127.0.0.1/live/") + stream_name;
}