// camera_to_rtsp.cpp
#include <gst/gst.h>
#include <gst/rtsp-server/rtsp-server.h>
#include <iostream>
#include <vector>
#include <atomic>
#include <thread>
#include <csignal>
#include <fstream>
#include <nlohmann/json.hpp>
#include <mutex>

using json = nlohmann::json;

GMainLoop *loop = nullptr;

// 全局退出标志
std::atomic<bool> g_running(true);

// Ctrl+C 信号处理
void signalHandler(int signum)
{
    g_running = false;
    if (loop)
        g_main_loop_quit(loop);
}

// GStreamer 日志处理
void gstreamer_log_handler(const gchar *domain, GLogLevelFlags level,
                           const gchar *message, gpointer)
{
    if (level & G_LOG_LEVEL_ERROR)
        std::cerr << "[GStreamer-ERROR] " << (domain ? domain : "unknown") << ": " << message << std::endl;
}

// 初始化 GStreamer
void init_gstreamer()
{
    gst_init(nullptr, nullptr);
    g_log_set_default_handler(gstreamer_log_handler, nullptr);
    // 设置GStreamer调试级别为警告及以上
    setenv("GST_DEBUG", "*:2", 1);
}

// 摄像头结构体
struct Camera
{
    std::string device;
    std::string name;
    int width, height, fps;
    bool enabled;
    GstElement *src = nullptr;
    GstRTSPMediaFactory *factory = nullptr;
};

// 创建RTSP媒体工厂
GstRTSPMediaFactory *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;
}

// 主函数
int main()
{
    signal(SIGINT, signalHandler);
    signal(SIGPIPE, SIG_IGN);
    init_gstreamer();

    // 读取配置文件
    std::ifstream ifs("config.json");
    if (!ifs.is_open())
    {
        std::cerr << "Failed to open config.json" << std::endl;
        return -1;
    }

    json j;
    ifs >> j;

    std::vector<Camera> cameras;
    for (auto &c : j["cameras"])
    {
        Camera cam;
        cam.device = c["device"];
        cam.name = c["name"];
        cam.width = c["width"];
        cam.height = c["height"];
        cam.fps = c["fps"];
        cam.enabled = c["enabled"];

        if (cam.enabled)
        {
            cameras.push_back(cam);
        }
    }

    // 创建RTSP服务器
    GstRTSPServer *server = gst_rtsp_server_new();
    gst_rtsp_server_set_service(server, "8554"); // 设置RTSP服务器端口

    // 获取服务器挂载点
    GstRTSPMountPoints *mounts = gst_rtsp_server_get_mount_points(server);

    // 为每个摄像头创建媒体工厂并添加到挂载点
    for (auto &cam : cameras)
    {
        if (!cam.enabled)
            continue;

        cam.factory = create_media_factory(cam);
        std::string mount_point = "/" + cam.name;
        gst_rtsp_mount_points_add_factory(mounts, mount_point.c_str(), cam.factory);
        std::cout << "Camera '" << cam.name << "' available at rtsp://localhost:8554" << mount_point << std::endl;
    }

    // 释放挂载点引用
    g_object_unref(mounts);

    // 附加服务器到默认主上下文
    loop = g_main_loop_new(nullptr, FALSE);
    gst_rtsp_server_attach(server, nullptr);

    std::cout << "RTSP server running on rtsp://localhost:8554" << std::endl;
    std::cout << "Press Ctrl+C to stop" << std::endl;

    g_main_loop_run(loop); // 运行主循环

    // 清理资源
    g_object_unref(server);
    g_main_loop_unref(loop);

    std::cout << "RTSP server stopped." << std::endl;
    return 0;
}