// rtsp_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 <sys/types.h>
#include <unistd.h>

#include <chrono>
#include <cstring>
#include <iostream>
#include <string>
#include <thread>

#include "logger.hpp"

// ---------- 小工具 ----------

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

static 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 "";  // 没找到
}

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

// ---------- 静态成员 ----------

std::unordered_map<std::string, std::unique_ptr<RTMPManager::StreamContext>> RTMPManager::streams;
std::mutex RTMPManager::streams_mutex;
RTMPManager::StreamCallback RTMPManager::status_callback = nullptr;

// ---------- 内部工具 ----------

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.");
}

void RTMPManager::set_status_callback(StreamCallback cb) { status_callback = std::move(cb); }

void RTMPManager::update_status(const std::string &key, const StreamStatus &status)
{
    {
        std::lock_guard<std::mutex> lock(streams_mutex);
        auto it = streams.find(key);
        if (it != streams.end()) it->second->status = status;
    }
    if (status_callback) status_callback(key, status);
}

// 决定 app：MAIN -> record（录像），SUB -> live（按需）
static inline std::string pick_app(StreamType type) { return (type == StreamType::MAIN) ? "record" : "live"; }

GstElement *RTMPManager::create_pipeline(const Camera &cam, StreamType type)
{
    int width = cam.width, height = cam.height, fps = cam.fps, bitrate = cam.bitrate;
    if (type == StreamType::SUB)
    {
        bitrate = std::max(300000, bitrate / 2);
    }

    const std::string stream_name = cam.name + stream_type_suffix(type);
    const std::string app = pick_app(type);

    // NV12 -> mpph264enc -> h264parse -> flvmux(+静音音轨) -> rtmpsink
    std::string pipeline_str = "v4l2src device=" + cam.device + " ! video/x-raw,width=" + std::to_string(width) +
                               ",height=" + std::to_string(height) + ",framerate=" + std::to_string(fps) +
                               "/1 "
                               "! videoconvert ! video/x-raw,format=NV12 "
                               "! mpph264enc bps=" +
                               std::to_string(bitrate) + " gop=" + std::to_string(fps) +
                               " "
                               "! h264parse "
                               "! flvmux name=mux streamable=true "
                               "audiotestsrc wave=silence ! audioconvert ! audioresample ! voaacenc ! aacparse ! mux. "
                               "mux. ! rtmpsink name=rtmp_sink location=\"rtmp://127.0.0.1/" +
                               app + "/" + stream_name + " live=1\" sync=false";

    LOG_INFO("[RTMP] Creating pipeline for '" + stream_name + "' -> app '" + app + "': " + pipeline_str);

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

// 摄像头在配置中的索引（用于 reply.loc）
static int get_camera_index(const std::string &name)
{
    for (size_t i = 0; i < g_app_config.cameras.size(); ++i)
        if (g_app_config.cameras[i].name == name) return static_cast<int>(i);
    return -1;
}

// ---------- 对外接口：启动/停止 ----------

RTMPManager::StreamResultInfo RTMPManager::start_camera(const Camera &cam, StreamType type)
{
    StreamResultInfo res;
    res.loc = get_camera_index(cam.name);
    res.url = get_stream_url(cam.name, type);

    if (res.loc < 0 || res.loc >= static_cast<int>(g_app_config.cameras.size()))
    {
        res.result = 1;
        res.reason = "Invalid channel index";
        return res;
    }

    // 主码流（record）允许设备缺失时也进入“重试守护”，所以这里只在 SUB 时严格检查
    if (type == StreamType::SUB && !device_exists(cam.device))
    {
        res.result = 1;
        res.reason = "Device not found: " + cam.device;
        return res;
    }

    const std::string key = make_stream_key(cam.name, type);

    std::unique_ptr<StreamContext> ctx;
    std::future<StreamStatus> status_future;

    {
        std::lock_guard<std::mutex> lock(streams_mutex);
        auto it = streams.find(key);

        // 若旧线程仍在运行，先安全停止并移除
        if (it != streams.end())
        {
            if (it->second->running.load())
            {
                LOG_WARN("[RTMP] Restarting existing stream: " + key);
                it->second->running.store(false);
                if (it->second->thread.joinable()) it->second->thread.join();
            }
            streams.erase(it);
        }

        ctx = std::make_unique<StreamContext>();
        ctx->running.store(true);
        status_future = ctx->start_promise.get_future();

        StreamContext *ctx_ptr = ctx.get();
        ctx->thread = std::thread(
            [cam, type, ctx_ptr]()
            {
                try
                {
                    RTMPManager::stream_loop(cam, type, ctx_ptr);
                }
                catch (const std::exception &e)
                {
                    LOG_ERROR("[RTMP] Exception in stream thread: " + std::string(e.what()));
                }
                catch (...)
                {
                    LOG_ERROR("[RTMP] Unknown exception in stream thread");
                }
            });

        streams.emplace(key, std::move(ctx));
    }

    // 等待首帧或错误，最多 7 秒
    if (status_future.wait_for(std::chrono::seconds(7)) == std::future_status::ready)
    {
        const StreamStatus s = status_future.get();
        res.result = s.running ? 0 : 1;
        res.reason = s.running ? "Started OK" : (s.last_error.empty() ? "Failed to start" : s.last_error);
    }
    else
    {
        res.result = 1;
        res.reason = "Timeout waiting for stream";
    }

    return res;
}

RTMPManager::StreamResultInfo RTMPManager::stop_camera(const std::string &cam_name, StreamType type)
{
    StreamResultInfo res;
    res.loc = get_camera_index(cam_name);
    res.url = get_stream_url(cam_name, type);

    if (res.loc < 0 || res.loc >= static_cast<int>(g_app_config.cameras.size()))
    {
        res.result = 1;
        res.reason = "Invalid channel index";
        return res;
    }

    std::unique_ptr<StreamContext> ctx;
    std::string key = make_stream_key(cam_name, type);

    {
        std::lock_guard<std::mutex> lock(streams_mutex);
        auto it = streams.find(key);
        if (it == streams.end())
        {
            res.result = 0;
            res.reason = "Already stopped (no active stream)";
            return res;
        }

        ctx = std::move(it->second);
        streams.erase(it);
    }

    bool was_running = ctx->running.load();
    ctx->running.store(false);
    if (ctx->thread.joinable()) ctx->thread.join();

    if (was_running)
    {
        res.result = 0;
        res.reason = "Stopped manually";
    }
    else
    {
        res.result = 1;
        res.reason = "Not running (stream never started)";
    }

    return res;
}

// ---------- 核心：推流循环（带重试策略） ----------

void RTMPManager::stream_loop(Camera cam, StreamType type, StreamContext *ctx)
{
    const std::string key = make_stream_key(cam.name, type);

    auto try_set_start = [&](const StreamStatus &st)
    {
        bool expected = false;
        if (ctx && ctx->start_promise_set.compare_exchange_strong(expected, true))
        {
            try
            {
                ctx->start_promise.set_value(st);
            }
            catch (...)
            {
            }
        }
    };

    // MAIN（record）= 永久自动重试；SUB（live）= 限次重试
    if (type == StreamType::MAIN)
    {
        int backoff_ms = RETRY_BASE_DELAY_MS;  // 可指数退避
        while (ctx->running.load())
        {
            const bool ok = do_stream_once(cam, type, ctx);
            if (!ok && ctx->running.load())
            {
                LOG_WARN("[RTMP] MAIN(record) stream lost, retry in " + std::to_string(backoff_ms) + "ms: " + cam.name);
                std::this_thread::sleep_for(std::chrono::milliseconds(backoff_ms));
                backoff_ms = std::min(backoff_ms * 2, 60000);  // up to 60s
            }
            else
            {
                backoff_ms = RETRY_BASE_DELAY_MS;  // 成功后重置退避
            }
        }
    }
    else  // SUB / live
    {
        int retries = 0;
        while (ctx->running.load())
        {
            const bool ok = do_stream_once(cam, type, ctx);
            if (ok) break;  // 正常退出（被 stop 或 EOS）
            retries++;
            if (retries >= LIVE_MAX_RETRIES || !ctx->running.load())
            {
                LOG_ERROR("[RTMP] SUB(live) stream failed after retries, giving up: " + cam.name);
                break;
            }
            LOG_WARN("[RTMP] SUB(live) retry " + std::to_string(retries) + "/" + std::to_string(LIVE_MAX_RETRIES) +
                     " in " + std::to_string(RETRY_BASE_DELAY_MS) + "ms: " + cam.name);
            std::this_thread::sleep_for(std::chrono::milliseconds(RETRY_BASE_DELAY_MS));
        }
    }

    ctx->status.running = false;
}

// 单次推流：创建 pipeline -> PLAYING -> loop 直到 ERROR/EOS/stop
bool RTMPManager::do_stream_once(const Camera &cam, StreamType type, StreamContext *ctx)
{
    const std::string key = make_stream_key(cam.name, type);

    auto try_set_start = [&](const StreamStatus &st)
    {
        bool expected = false;
        if (ctx && ctx->start_promise_set.compare_exchange_strong(expected, true))
        {
            try
            {
                ctx->start_promise.set_value(st);
            }
            catch (...)
            {
            }
        }
    };

    RTMPManager::StreamStatus status;
    status.running = false;
    status.last_result = StreamResult::UNKNOWN;
    status.last_error.clear();

    GstElement *pipeline = create_pipeline(cam, type);
    if (!pipeline)
    {
        status.last_result = StreamResult::PIPELINE_ERROR;
        status.last_error = "Failed to create pipeline";
        update_status(key, status);
        try_set_start(status);
        return false;
    }

    GstBus *bus = gst_element_get_bus(pipeline);
    gst_element_set_state(pipeline, GST_STATE_PLAYING);

    bool started_reported = false;
    auto t0 = std::chrono::steady_clock::now();
    const int first_frame_timeout_s = 5;
    const int connect_guard_ms = 2000;

    bool need_restart = false;
    bool ok = false;

    while (true)
    {
        if (!ctx->running.load())
        {
            status.running = false;
            status.last_result = StreamResult::UNKNOWN;
            status.last_error = "Stream stopped manually";
            update_status(key, status);
            try_set_start(status);
            break;
        }

        // 首帧/连通性超时保护
        if (!started_reported)
        {
            auto elapsed_s =
                std::chrono::duration_cast<std::chrono::seconds>(std::chrono::steady_clock::now() - t0).count();
            if (elapsed_s > first_frame_timeout_s)
            {
                status.running = false;
                status.last_result = StreamResult::TIMEOUT;
                status.last_error = "No frames/connection established within timeout";
                update_status(key, status);
                try_set_start(status);
                need_restart = true;
                break;
            }
        }

        GstMessage *msg =
            gst_bus_timed_pop_filtered(bus, 200 * GST_MSECOND,
                                       (GstMessageType)(GST_MESSAGE_ERROR | GST_MESSAGE_EOS |
                                                        GST_MESSAGE_STATE_CHANGED | GST_MESSAGE_STREAM_STATUS));

        if (!msg)
        {
            // 过了 connect_guard_ms 且 rtmpsink 进入 PLAYING，认为启动成功
            if (!started_reported)
            {
                auto elapsed_ms =
                    std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::steady_clock::now() - t0)
                        .count();
                if (elapsed_ms >= connect_guard_ms)
                {
                    GstElement *sink = gst_bin_get_by_name(GST_BIN(pipeline), "rtmp_sink");
                    if (sink)
                    {
                        GstState cur, pending;
                        if (gst_element_get_state(sink, &cur, &pending, 0) == GST_STATE_CHANGE_SUCCESS &&
                            cur == GST_STATE_PLAYING)
                        {
                            status.running = true;
                            ctx->status.running = true;
                            status.last_result = StreamResult::OK;
                            status.last_error.clear();
                            update_status(key, status);
                            try_set_start(status);
                            started_reported = true;
                            LOG_INFO("[RTMP] Guard-start OK for '" + cam.name + "'");
                        }
                        gst_object_unref(sink);
                    }
                }
            }
            continue;
        }

        switch (GST_MESSAGE_TYPE(msg))
        {
            case GST_MESSAGE_STREAM_STATUS:
            {
                GstStreamStatusType type_ss;
                GstElement *owner = nullptr;
                gst_message_parse_stream_status(msg, &type_ss, &owner);
                if (!started_reported && owner)
                {
                    const gchar *oname = GST_OBJECT_NAME(owner);
                    if (oname && std::strcmp(oname, "rtmp_sink") == 0)
                    {
                        if (type_ss == GST_STREAM_STATUS_TYPE_CREATE || type_ss == GST_STREAM_STATUS_TYPE_ENTER ||
                            type_ss == GST_STREAM_STATUS_TYPE_START)
                        {
                            status.running = true;
                            ctx->status.running = true;
                            status.last_result = StreamResult::OK;
                            status.last_error.clear();
                            update_status(key, status);
                            try_set_start(status);
                            started_reported = true;
                            LOG_INFO(std::string("[RTMP] Connected (STREAM_STATUS) for '") + cam.name + "'");
                        }
                    }
                }
                break;
            }

            case GST_MESSAGE_STATE_CHANGED:
                // 可用于扩展日志；不以 pipeline 的 PLAYING 作为成功判据
                break;

            case GST_MESSAGE_ERROR:
            {
                GError *err = nullptr;
                gchar *dbg = nullptr;
                gst_message_parse_error(msg, &err, &dbg);

                status.running = false;
                status.last_result = StreamResult::CONNECTION_FAIL;
                status.last_error = err ? err->message : "GStreamer error";

                LOG_ERROR("[RTMP] Stream error from '" + cam.name + "': " + status.last_error);

                ctx->status.running = false;
                need_restart = true;

                if (err) g_error_free(err);
                if (dbg) g_free(dbg);
                update_status(key, status);
                try_set_start(status);
                break;
            }

            case GST_MESSAGE_EOS:
            {
                status.running = false;
                status.last_result = StreamResult::EOS_RECEIVED;
                status.last_error = "EOS received";
                update_status(key, status);
                try_set_start(status);
                need_restart = true;
                break;
            }

            default:
                break;
        }

        gst_message_unref(msg);

        if (need_restart) break;
        if (started_reported)
        {
            // 正常运行中，继续监听
        }
    }

    // 收尾
    gst_element_set_state(pipeline, GST_STATE_NULL);
    if (bus) gst_object_unref(bus);
    gst_object_unref(pipeline);

    ok = started_reported && !need_restart;  // 若在 stop 前一直运行且未触发重启则认为 ok
    return ok;
}

// ---------- 其他工具 ----------

void RTMPManager::stop_all()
{
    std::vector<std::unique_ptr<StreamContext>> ctxs;
    {
        std::lock_guard<std::mutex> lock(streams_mutex);
        for (auto &kv : streams) kv.second->running.store(false);
        for (auto &kv : streams) ctxs.push_back(std::move(kv.second));
        streams.clear();
    }

    for (auto &ctx : ctxs)
        if (ctx->thread.joinable()) ctx->thread.join();

    LOG_INFO("[RTMP] stop_all completed.");
}

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

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

std::string RTMPManager::get_stream_url(const std::string &cam_name, StreamType type)
{
    // 你可以把这里的网卡名替换成你的默认上行网卡
    std::string ip = get_ip_address("enP2p33s0");
    if (ip.empty()) ip = "127.0.0.1";

    const std::string app = pick_app(type);
    const std::string stream_name = make_stream_key(cam_name, type);

    // 返回 WebRTC 拉流地址（WHEP）
    return "http://" + ip + ":1985/rtc/v1/whep/?app=" + app + "&stream=" + stream_name;
}

// 批量处理
std::vector<RTMPManager::StreamResultInfo> RTMPManager::process_push_request(const VideoPushRequest &req)
{
    std::vector<StreamResultInfo> results;
    std::vector<std::future<StreamResultInfo>> futures;

    for (const auto &item : req.data)
    {
        StreamType type = (item.streamType == 0) ? StreamType::MAIN : StreamType::SUB;

        for (int ch : item.channels)
        {
            if (ch < 0 || ch >= static_cast<int>(g_app_config.cameras.size())) continue;

            const auto &cam = g_app_config.cameras[ch];

            if (item.switchVal == 0)
            {
                futures.emplace_back(
                    std::async(std::launch::async, [&, cam, type]() { return start_camera(cam, type); }));
            }
            else
            {
                futures.emplace_back(
                    std::async(std::launch::async, [&, cam, type]() { return stop_camera(cam.name, type); }));
            }
        }
    }

    for (auto &f : futures)
    {
        try
        {
            results.push_back(f.get());
        }
        catch (const std::exception &e)
        {
            StreamResultInfo err;
            err.result = 1;
            err.reason = std::string("Exception: ") + e.what();
            results.push_back(err);
        }
    }

    return results;
}

void RTMPManager::start_all_record_streams()
{
    LOG_INFO("[RTMP] Auto-starting all record (MAIN) streams...");

    for (const auto &cam : g_app_config.cameras)
    {
        // 检查是否已经存在
        if (is_streaming(cam.name, StreamType::MAIN))
        {
            LOG_INFO("[RTMP] Record stream already running: " + cam.name);
            continue;
        }

        auto res = start_camera(cam, StreamType::MAIN);
        if (res.result == 0)
        {
            LOG_INFO("[RTMP] Record stream started for " + cam.name + ": " + res.reason);
        }
        else
        {
            LOG_WARN("[RTMP] Failed to start record stream for " + cam.name + ": " + res.reason);
        }
    }

    LOG_INFO("[RTMP] Auto-start for record streams done.");
}