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

// 静态变量定义
GMainLoop *RTSPManager::loop = nullptr;
GstRTSPServer *RTSPManager::server = nullptr;
std::unordered_map<std::string, bool> RTSPManager::streaming_status;
std::unordered_map<std::string, GstRTSPMediaFactory *> RTSPManager::mounted_factories;
std::mutex RTSPManager::mounted_factories_mutex;

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

GstRTSPMediaFactory *RTSPManager::create_media_factory(const Camera &cam)
{
    std::string launch_str =
        "( v4l2src device=" + cam.device +
        " ! video/x-raw,format=NV12,width=" + std::to_string(cam.width) +
        ",height=" + std::to_string(cam.height) +
        ",framerate=" + std::to_string(cam.fps) + "/1"
                                                  " ! videoconvert ! queue ! mpph264enc ! rtph264pay name=pay0 pt=96 )";

    GstRTSPMediaFactory *factory = gst_rtsp_media_factory_new();
    gst_rtsp_media_factory_set_launch(factory, launch_str.c_str());
    gst_rtsp_media_factory_set_shared(factory, TRUE);

    return factory;
}

void RTSPManager::start(const std::vector<Camera> &cameras)
{
    server = gst_rtsp_server_new();
    gst_rtsp_server_set_service(server, "8554");

    // === 不再在启动时挂载摄像头，由调度指令控制推流 ===

    loop = g_main_loop_new(nullptr, FALSE);
    gst_rtsp_server_attach(server, nullptr);

    LOG_INFO("[RTSP] Server running on rtsp://localhost:8554");
    g_main_loop_run(loop);

    // loop 退出后释放资源
    if (server)
    {
        g_object_unref(server);
        server = nullptr;
    }
    if (loop)
    {
        g_main_loop_unref(loop);
        loop = nullptr;
    }
    LOG_INFO("[RTSP] Server stopped.");
}

void RTSPManager::stop()
{
    if (loop)
    {
        // 仅退出 loop，不 unref server
        g_main_context_invoke(nullptr, [](gpointer data) -> gboolean
                              {
            GMainLoop *loop = static_cast<GMainLoop*>(data);
            g_main_loop_quit(loop);
            return G_SOURCE_REMOVE; }, loop);
    }
}

// 公共接口：挂载摄像头（可以被任意线程调用，立即返回）
// 将实际挂载工作派发到 main loop 线程执行，避免跨线程直接调用 GStreamer。
void RTSPManager::mount_camera(const Camera &cam)
{
    // 通过 new 一个临时 Camera 拷贝，主loop callback 会 delete 它
    Camera *camCopy = new Camera(cam);
    // 派发到主线程执行
    g_main_context_invoke(nullptr, [](gpointer data) -> gboolean
                          { return mount_camera_in_main(data); }, camCopy);
}

// 公共接口：卸载摄像头（可以被任意线程调用，立即返回）
// 将实际卸载工作派发到 main loop 线程执行。
void RTSPManager::unmount_camera(const Camera &cam)
{
    Camera *camCopy = new Camera(cam);
    g_main_context_invoke(nullptr, [](gpointer data) -> gboolean
                          { return unmount_camera_in_main(data); }, camCopy);
}

// 查询播放状态（线程安全）
bool RTSPManager::is_streaming(const std::string &cam_name)
{
    std::lock_guard<std::mutex> lock(mounted_factories_mutex);
    auto it = streaming_status.find(cam_name);
    if (it != streaming_status.end())
        return it->second;
    return false;
}

// -------------------- private static callbacks --------------------

gboolean RTSPManager::mount_camera_in_main(gpointer data)
{
    Camera *cam = static_cast<Camera *>(data);
    if (!cam)
        return G_SOURCE_REMOVE;

    if (!server)
    {
        LOG_ERROR("[RTSP] mount_camera_in_main: server is null");
        delete cam;
        return G_SOURCE_REMOVE;
    }

    GstRTSPMountPoints *mounts = gst_rtsp_server_get_mount_points(server);
    if (!mounts)
    {
        LOG_ERROR("[RTSP] mount_camera_in_main: failed to get mounts");
        delete cam;
        return G_SOURCE_REMOVE;
    }

    std::string mount_point = "/" + cam->name;
    GstRTSPMediaFactory *factory = create_media_factory(*cam);
    if (!factory)
    {
        LOG_ERROR("[RTSP] mount_camera_in_main: failed to create factory for " + cam->name);
        g_object_unref(mounts);
        delete cam;
        return G_SOURCE_REMOVE;
    }

    gst_rtsp_mount_points_add_factory(mounts, mount_point.c_str(), factory);
    g_object_unref(mounts);

    {
        std::lock_guard<std::mutex> lock(mounted_factories_mutex);
        mounted_factories[cam->name] = factory;
        streaming_status[cam->name] = true;
    }

    LOG_INFO("[RTSP] Camera '" + cam->name + "' mounted at rtsp://localhost:8554" + mount_point);
    delete cam;
    return G_SOURCE_REMOVE;
}

gboolean RTSPManager::unmount_camera_in_main(gpointer data)
{
    Camera *cam = static_cast<Camera *>(data);
    if (!cam)
        return G_SOURCE_REMOVE;

    if (!server)
    {
        LOG_ERROR("[RTSP] unmount_camera_in_main: server is null");
        delete cam;
        return G_SOURCE_REMOVE;
    }

    GstRTSPMountPoints *mounts = gst_rtsp_server_get_mount_points(server);
    if (!mounts)
    {
        LOG_ERROR("[RTSP] unmount_camera_in_main: failed to get mounts");
        delete cam;
        return G_SOURCE_REMOVE;
    }

    std::string mount_point = "/" + cam->name;
    gst_rtsp_mount_points_remove_factory(mounts, mount_point.c_str());
    g_object_unref(mounts);

    {
        std::lock_guard<std::mutex> lock(mounted_factories_mutex);
        auto it = mounted_factories.find(cam->name);
        if (it != mounted_factories.end())
        {
            if (it->second)
                g_object_unref(it->second);
            mounted_factories.erase(it);
        }
        streaming_status[cam->name] = false;
    }

    LOG_INFO("[RTSP] Camera '" + cam->name + "' unmounted.");
    delete cam;
    return G_SOURCE_REMOVE;
}