#include "serial_AT.hpp"

#include <algorithm>
#include <atomic>
#include <chrono>
#include <mutex>
#include <sstream>
#include <thread>

#include "httplib.h"
#include "logger.hpp"
#include "nlohmann/json.hpp"
#include "serial_port.h"

// ================== 全局 IMEI ==================
std::string IMEI;
std::mutex imei_mutex;

// ================== 运行控制 ==================
static std::atomic<bool> serial_at_running{false};

// ================== AT 任务结构 ==================
struct AtTask
{
    std::string cmd;
    int max_retries;
    int sent_count;
    std::chrono::steady_clock::time_point last_sent;
};

static std::unique_ptr<SerialPort> serial_at;
static std::thread serial_at_sender;
static std::mutex at_tasks_mutex;

static std::unique_ptr<httplib::Server> http_server;
static std::thread http_thread;

static bool is_imei_ready()
{
    std::lock_guard<std::mutex> lock(imei_mutex);
    return !IMEI.empty();
}

static std::string get_imei()
{
    std::lock_guard<std::mutex> lock(imei_mutex);
    return IMEI;
}

void start_http_server(int port)
{
    http_server = std::make_unique<httplib::Server>();

    http_server->Post("/api/v1/device/register",
                      [](const httplib::Request& req, httplib::Response& res)
                      {
                          LOG_INFO("[http] /device/register called");

                          // 解析 A 的信息（可选，先简单点）
                          LOG_INFO("[http] payload: " + req.body);

                          if (!is_imei_ready())
                          {
                              res.status = 503;
                              res.set_content(R"({"ok":false,"error":"imei_not_ready"})", "application/json");
                              return;
                          }

                          std::string imei = get_imei();

                          nlohmann::json j;
                          j["ok"] = true;
                          j["server"] = {{"device_type", "tbox"}, {"imei", imei}, {"fw", "b-v2.1.0"}};

                          res.set_content(j.dump(-1), "application/json");
                      });

    http_thread = std::thread(
        [port]()
        {
            LOG_INFO("[http] Server listening on port " + std::to_string(port));
            http_server->listen("0.0.0.0", port);
        });
}

void stop_http_server()
{
    if (http_server)
    {
        http_server->stop();
    }

    if (http_thread.joinable())
    {
        http_thread.join();
    }

    http_server.reset();
}

// 只保留一个任务：AT+GSN
static std::vector<AtTask> at_tasks = {{"AT+GSN", 3, 0, {}}};

// ================== 发送线程 ==================
static void serial_at_send_loop()
{
    LOG_INFO("[serial_at] Sender thread started");

    while (serial_at_running.load(std::memory_order_relaxed))
    {
        if (!serial_at || !serial_at->is_open())
        {
            std::this_thread::sleep_for(std::chrono::seconds(1));
            continue;
        }

        auto now = std::chrono::steady_clock::now();

        {
            std::lock_guard<std::mutex> lock(at_tasks_mutex);

            for (auto it = at_tasks.begin(); it != at_tasks.end();)
            {
                auto& task = *it;

                if (task.sent_count >= task.max_retries)
                {
                    it = at_tasks.erase(it);
                    continue;
                }

                if (task.last_sent.time_since_epoch().count() == 0 ||
                    std::chrono::duration_cast<std::chrono::seconds>(now - task.last_sent).count() >= 5)
                {
                    serial_at->send_data(task.cmd + "\r\n");
                    task.sent_count++;
                    task.last_sent = now;
                }

                ++it;
            }
        }

        std::this_thread::sleep_for(std::chrono::seconds(1));
    }

    LOG_INFO("[serial_at] Sender thread exiting");
}

// ================== 接收处理 ==================
static void handle_serial_at_data(const std::string& data)
{
    std::istringstream iss(data);
    std::string line;

    while (std::getline(iss, line))
    {
        // trim
        line.erase(0, line.find_first_not_of(" \t\r\n"));
        line.erase(line.find_last_not_of(" \t\r\n") + 1);

        // IMEI：14~17 位纯数字
        if (line.size() >= 14 && line.size() <= 17 && std::all_of(line.begin(), line.end(), ::isdigit))
        {
            {
                std::lock_guard<std::mutex> lock(imei_mutex);
                IMEI = line;
            }

            LOG_INFO("[serial_at] IMEI = " + line);

            std::lock_guard<std::mutex> lock(at_tasks_mutex);
            at_tasks.clear();
            return;
        }
    }
}

// ================== 初始化 ==================
void init_serial_at(const std::string& device, int baudrate)
{
    if (serial_at_running.load())
    {
        LOG_WARN("[serial_at] Already running");
        return;
    }

    serial_at_running.store(true, std::memory_order_relaxed);

    serial_at = std::make_unique<SerialPort>("serial_at", device, baudrate, 5);
    serial_at->set_receive_callback(handle_serial_at_data);
    serial_at->start();

    serial_at_sender = std::thread(serial_at_send_loop);
}

// ================== 停止 ==================
void stop_serial_at()
{
    if (!serial_at_running.load()) return;

    LOG_INFO("[serial_at] Stopping...");

    serial_at_running.store(false, std::memory_order_relaxed);

    if (serial_at)
    {
        serial_at->stop();  // 关闭串口，解除阻塞
    }

    if (serial_at_sender.joinable())
    {
        serial_at_sender.join();
    }

    serial_at.reset();

    LOG_INFO("[serial_at] Stopped cleanly");
}