/*
本程序主要用于初始化网络配置,使4g模块可以正常上网
*/

#include <iostream>
#include <fcntl.h>
#include <unistd.h>
#include <termios.h>
#include <poll.h>
#include <cstring>
#include <thread>

using namespace std;

// 串口设备
string Serious = "/dev/ttyUSB2";

// 设置网络
void SetNet();

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

    this_thread::sleep_for(chrono::seconds(3));

    SetNet();
    return 0;
}

// 设置网络
void SetNet()
{
    auto configure_serial = [](int fd) -> bool
    {
        struct termios options;
        if (tcgetattr(fd, &options) != 0)
            return false;

        cfsetispeed(&options, B115200);
        cfsetospeed(&options, B115200);

        options.c_cflag |= (CLOCAL | CREAD);
        options.c_cflag &= ~PARENB; // 无校验
        options.c_cflag &= ~CSTOPB; // 1 位停止位
        options.c_cflag &= ~CSIZE;
        options.c_cflag |= CS8;      // 8 位数据位
        options.c_cflag &= ~CRTSCTS; // 关闭硬件流控

        options.c_iflag &= ~(IXON | IXOFF | IXANY); // 关闭软件流控
        options.c_iflag &= ~(INLCR | ICRNL);

        options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); // 原始模式
        options.c_oflag &= ~OPOST;                          // 原始输出

        options.c_cc[VMIN] = 0;   // 非阻塞读取
        options.c_cc[VTIME] = 10; // 1.0s 读超时

        if (tcsetattr(fd, TCSANOW, &options) != 0)
            return false;
        tcflush(fd, TCIOFLUSH);
        return true;
    };

    auto write_all = [](int fd, const std::string &data) -> bool
    {
        const char *p = data.c_str();
        size_t left = data.size();
        while (left > 0)
        {
            ssize_t n = write(fd, p, left);
            if (n < 0)
            {
                if (errno == EINTR)
                    continue;
                return false;
            }
            left -= static_cast<size_t>(n);
            p += n;
        }
        return true;
    };

    auto send_at = [&](int fd, const std::string &cmd, std::string &resp, int timeout_ms = 3000) -> bool
    {
        std::string line = cmd + "\r\n";
        if (!write_all(fd, line))
            return false;

        resp.clear();
        char buf[256];
        int elapsed = 0;
        while (elapsed < timeout_ms)
        {
            struct pollfd pfd{fd, POLLIN, 0};
            int pr = poll(&pfd, 1, 200);
            if (pr > 0 && (pfd.revents & POLLIN))
            {
                ssize_t n = read(fd, buf, sizeof(buf));
                if (n > 0)
                {
                    resp.append(buf, buf + n);
                    if (resp.find("\r\nOK\r\n") != std::string::npos ||
                        resp.find("\nOK\n") != std::string::npos ||
                        resp.find("OK") != std::string::npos)
                        return true;
                    if (resp.find("ERROR") != std::string::npos)
                        return false;
                }
            }
            elapsed += 200;
        }
        return false; // 超时
    };

    int fd = open(Serious.c_str(), O_RDWR | O_NOCTTY | O_NONBLOCK);
    if (fd < 0)
    {
        std::cerr << "无法打开串口: " << Serious << "\n";
        return;
    }
    // 设为阻塞
    int flags = fcntl(fd, F_GETFL, 0);
    fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);

    if (!configure_serial(fd))
    {
        std::cerr << "串口参数配置失败\n";
        close(fd);
        return;
    }

    std::string resp;
    // 0) 连续握手，确保 AT 可用（最多 10 次）
    {
        bool ok = false;
        for (int i = 1; i <= 10; ++i)
        {
            if (send_at(fd, "AT", resp, 500))
            {
                ok = true;
                break;
            }
            usleep(500 * 1000);
        }
        if (!ok)
        {
            std::cerr << "AT 握手失败，模块未响应\n";
            close(fd);
            return;
        }
    }

    // 1) 打开功能
    if (!send_at(fd, "AT+CFUN=1", resp))
    {
        std::cerr << "AT+CFUN=1 失败: " << resp << "\n";
    }
    else
    {
        std::cout << "AT+CFUN=1 OK\n";
    }

    // 1.1) 等 SIM 就绪（AT+CPIN? 返回 READY，最多 30 秒）
    {
        bool ready = false;
        for (int i = 0; i < 60; ++i)
        {
            if (send_at(fd, "AT+CPIN?", resp, 500) && resp.find("READY") != std::string::npos)
            {
                ready = true;
                break;
            }
            usleep(500 * 1000);
        }
        if (!ready)
            std::cerr << "SIM 未就绪，后续可能失败\n";
    }

    // 2) 设置 PDP 上下文：APN = ipn（请按运营商实际 APN 调整）
    if (!send_at(fd, "AT+CGDCONT=1,\"IP\",\"ipn\"", resp))
    {
        std::cerr << "AT+CGDCONT 设置失败: " << resp << "\n";
    }
    else
    {
        std::cout << "AT+CGDCONT OK\n";
    }

    // 2.1) 等驻网（AT+CEREG? 返回 ,1 或 ,5，最多 60 秒）
    {
        auto registered = [](const std::string &s)
        { return s.find(",1") != std::string::npos || s.find(",5") != std::string::npos; };
        bool ok = false;
        for (int i = 0; i < 60; ++i)
        {
            if (send_at(fd, "AT+CEREG?", resp, 500) && registered(resp))
            {
                ok = true;
                break;
            }
            usleep(1000 * 1000);
        }
        if (!ok)
            std::cerr << "未驻网，继续尝试拨号但成功率较低\n";
    }

    // 3) 打开网卡/拨号（Quectel 私有指令示例）- 失败重试 5 次
    {
        bool ok = false;
        for (int attempt = 1; attempt <= 5; ++attempt)
        {
            resp.clear();
            if (send_at(fd, "AT+QNETDEVCTL=1,1,1", resp))
            {
                std::cout << "AT+QNETDEVCTL OK (attempt " << attempt << ")\n";
                ok = true;
                break;
            }
            std::cerr << "AT+QNETDEVCTL 失败 (attempt " << attempt << "/5): " << resp << "\n";
            usleep(1000 * 1000); // 1s 间隔
        }
        if (!ok)
        {
            std::cerr << "AT+QNETDEVCTL 连续 5 次失败，退出本步骤\n";
        }
    }

    close(fd);
}