// 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 <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
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 "";
}

// ========== 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";
    const std::string location = "rtmp://127.0.0.1:1935/" + app + "/" + stream_name + "?vhost=live";

    // 给关键元素起名字：src, vc, enc, par, mux, sink, tee
    std::string pipeline_str = "v4l2src name=src device=" + cam.device +
                               " ! video/x-raw,width=" + std::to_string(width) + ",height=" + std::to_string(height) +
                               ",framerate=" + std::to_string(fps) +
                               "/1 "
                               "! videoconvert name=vc ! video/x-raw,format=NV12 "
                               "! tee name=t "
                               "t. ! queue "
                               "! mpph264enc name=enc bps=" +
                               std::to_string(bitrate) + " gop=" + std::to_string(fps) +
                               " "
                               "! h264parse name=par "
                               "! flvmux name=mux streamable=true "
                               "audiotestsrc wave=silence ! audioconvert ! audioresample ! voaacenc ! aacparse ! mux. "
                               "mux. ! rtmpsink name=sink location=\"" +
                               location +
                               "\" sync=false "
                               // 预留第二路 tee 分支（以后加叠加/探测都行），先丢掉
                               "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)
    {
        // 设备是否存在
        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;
        }

        // 创建管线
        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);

        // 在 videoconvert 的 src pad 上挂 probe 判断是否有帧流过
        bool got_frame = false;
        {
            GstElement *vc = gst_bin_get_by_name(GST_BIN(pipeline), "vc");
            if (vc)
            {
                GstPad *pad = gst_element_get_static_pad(vc, "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 + " - vc has no src pad?");
                }
                gst_object_unref(vc);
            }
            else
            {
                LOG_WARN("[RTMP] " + key + " - cannot find element 'vc' for pad-probe");
            }
        }

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

        // 等待进入 PLAYING（最长 5s）
        bool confirmed_running = false;
        {
            GstState state = GST_STATE_NULL, pending = GST_STATE_NULL;
            // 注意：第三个参数单位是纳秒，5s=5*GST_SECOND
            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;
        }

        // 运行中：5s 内必须看到帧，否则认定无信号重启
        const auto start_t = std::chrono::steady_clock::now();
        bool need_restart = false;

        while (ctx->running)
        {
            // 先检查帧
            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
            {
                // 一旦有帧，保持 running=true
                ctx->status.running = true;
                ctx->status.last_error.clear();
            }

            // 监听错误/EOS
            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;
        }

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

        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 = "192.168.3.211";  // fallback
    return "http://" + ip + ":1985/rtc/v1/whep/?app=record&stream=" + cam_name + "_main";
}

// ========== 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;
}