// main.cpp

#include "network/tcp_server.h"
#include "mqtt/mqtt_client.h"
#include "mqtt/mqtt_router.h"
#include "systemMonitor/system_monitor.h"
#include "spdlog/spdlog.h"
#include "deviceManager/device_manager.h" 
#include "dataCache/data_cache.h"
#include "dataCache/cache_uploader.h"
#include "web/web_server.h"

#include <boost/asio.hpp>
#include <boost/asio/steady_timer.hpp>
#include <csignal>
#include <iostream>
#include <functional>

// 用于 ASIO 服务的全局 io_context
boost::asio::io_context g_io_context;

/**
 * @brief 处理终止信号 (SIGINT, SIGTERM).
 */
// void signalHandler(int signum) {
//     spdlog::warn("Interrupt signal ({}) received. Shutting down.", signum);
//     g_io_context.stop();
// }

/**
 * @brief 周期性轮询系统状态并发布到 MQTT
 */
void poll_system_metrics(
    boost::asio::steady_timer& timer,
    SystemMonitor::SystemMonitor& monitor,
    MqttClient& mqtt_client
) {
    if (g_io_context.stopped()) return;
    auto cpu_util = monitor.getCpuUtilization();
    auto mem_info = monitor.getMemoryInfo();
    double mem_total_gb = mem_info.total_kb / 1024.0 / 1024.0;

    std::string topic = "proxy/system_status";
    std::string payload = "{\"cpu_usage\":" + std::to_string(cpu_util.totalUsagePercentage) +
                          ",\"mem_total_gb\":" + std::to_string(mem_total_gb) + "}";
    mqtt_client.publish(topic, payload);
    spdlog::debug("System metrics published.");

    timer.expires_at(timer.expiry() + std::chrono::seconds(15));
    timer.async_wait(std::bind(poll_system_metrics, std::ref(timer), std::ref(monitor), std::ref(mqtt_client)));
}

int main(int argc, char* argv[]) {

    try {
        spdlog::set_level(spdlog::level::debug);
        spdlog::info("Edge Proxy starting up...");
    } catch (const spdlog::spdlog_ex& ex) {
        std::cerr << "Log initialization failed: " << ex.what() << std::endl;
        return 1;
    }

    // signal(SIGINT, signalHandler);
    // signal(SIGTERM, signalHandler);

    try {
        MqttClient mqtt_client("tcp://mqtt-broker:1883", "edge-proxy-main-client");
        MqttRouter mqtt_router(mqtt_client);
        std::vector<uint16_t> listen_ports = { 8888 };
        TCPServer tcp_server(g_io_context, listen_ports, mqtt_client);
        SystemMonitor::SystemMonitor monitor;

        DataCache data_cache;
        if (!data_cache.open("edge_data_cache.db")) { 
            spdlog::critical("Failed to initialize data cache. Exiting.");
            return 1;
        }
        CacheUploader cache_uploader(g_io_context, mqtt_client, data_cache);

        mqtt_client.set_connected_handler([&](const std::string& cause){
            spdlog::info("MQTT client connected: {}", cause);
            cache_uploader.start_upload();
        });
        
        mqtt_client.connect();
        mqtt_router.start();


        monitor.getCpuUtilization(); 
        boost::asio::steady_timer system_monitor_timer(g_io_context, std::chrono::seconds(15));
        system_monitor_timer.async_wait(std::bind(poll_system_metrics, std::ref(system_monitor_timer), std::ref(monitor), std::ref(mqtt_client)));

        // --- 创建包含缓存逻辑的统一数据上报回调函数 >>>
        auto report_to_mqtt = [&](const UnifiedData& data) {
            if (mqtt_client.is_connected()) {
                // 网络正常，直接上报
                std::string topic = "devices/" + data.device_id + "/data";
                g_io_context.post([&, topic, payload = data.data_json]() {
                    mqtt_client.publish(topic, payload, 1, false);
                });
            } else {
                // 网络断开，写入缓存
                spdlog::warn("MQTT disconnected. Caching data for device '{}'.", data.device_id);
                data_cache.add(data);
            }
        };

        // 实例化设备管理器并从文件加载所有设备 (使用新的回调) 
        DeviceManager device_manager(g_io_context, report_to_mqtt);
        device_manager.load_and_start("../config/devices.json");

        WebServer web_server(monitor, 8080); 
        web_server.start();

                // --- 2. <<< MODIFIED: 设置 Boost.Asio 风格的信号处理器 >>> ---
        boost::asio::signal_set signals(g_io_context, SIGINT, SIGTERM);
        signals.async_wait([&](const boost::system::error_code& error, int signal_number) {
            spdlog::warn("Interrupt signal ({}) received. Shutting down.", signal_number);

            // a. 首先停止所有数据采集线程
            spdlog::info("[Shutdown] A. Stopping device manager services...");
            device_manager.stop_all();

            // b. 停止Web服务器线程
            spdlog::info("[Shutdown] B. Stopping web server...");
            web_server.stop();

            // c. 断开MQTT连接 (这将释放它对io_context的'劫持')
            spdlog::info("[Shutdown] C. Disconnecting from MQTT broker...");
            mqtt_client.disconnect();

            // d. 最后，安全地停止io_context
            spdlog::info("[Shutdown] D. Stopping main event loop...");
            g_io_context.stop();
        });

        spdlog::info("All services are running. Press Ctrl+C to exit.");
        g_io_context.run();


    } catch (const std::exception& e) {
        spdlog::critical("An unhandled exception occurred: {}", e.what());
        return 1;
    }

    spdlog::info("Server has been shut down gracefully. Exiting.");
    return 0;
}