home-lab_watchdog_keepalive/main.cpp

#include <cstring>
#include <iostream>
#include <unistd.h>
#include "str_utils.h"
#include <sys/stat.h>
#include <filesystem>
#include <string>

#include <fcntl.h>
#include <termios.h>
#include <cstring>

#include "commands.h"

#ifndef VERSION
#define VERSION "unknown-DEV"
#endif

namespace fs = std::filesystem;

bool shortHand(const char* str, char shortHand);

int main(const int argc, char** argv) {

    bool init = false;
    char* device = nullptr;

    if (argc > 1) {
        for (int i = 1; i < argc; i++) {
            const char* arg = argv[i];
            if (strcmp(arg, "--help") == 0 || shortHand(arg, 'h')) {
                std::cout << "Server Arduino Watchdog version '" << VERSION << "' by Zacharias (c) 2025" << std::endl
                << std::endl
                << "Options:" << std::endl
                << "[requires root] -short --long-option Description" << std::endl
                << "[X]     --init          Initializes the Server end of this system, find the arduino and creates systemd services" << std::endl
                << "    -h  --help          Prints this help message" << std::endl
                << "    -b  --heartbeat     Sends a heartbeat to the arduino, Intended to be send by systemd unit and timer" << std::endl
                << "    -i  --info          Queries the Arduino Watchdog for status, like time before time-out" << std::endl
                << "    -v  --version       Print's the version" << std::endl
                << "        --arduino       Set's the Arduino to be used, skips the testing to find the watchdog device. OPS will fail if the device is not a Watchdog" << std::endl
                << std::endl
                << "Usages:" << std::endl
                << "    arduino_watchdog --arduino=/dev/ttyACM0 --init:" << std::endl
                << "        Will run init on device /dev/ttyACM0" << std::endl
                << "    arduino_watchdog --init:" << std::endl
                << "        Will run init and try to find the device" << std::endl
                ;
                return 0;
            }
            else if (strcmp(arg, "--init") == 0) {
                init = true;
            }
            else if (strcmp(arg, "--heartbeat") == 0 || shortHand(arg, 'b')) {
                // TODO: Send heartbeat
            }
            else if (strcmp(arg, "--info") == 0 || shortHand(arg, 'i')) {
                // TODO: Send info
                // TODO: Print response status
            }
            else if (strcmp(arg, "--version") == 0 || shortHand(arg, 'v')) {
                std::cout << VERSION << " by Zacharias (c) 2025" << std::endl;
            }
            else if (startsWith(arg, "--arduino=")) {
                device = strdup(arg + 10);
                std::cout << device << std::endl;
            }
            else {
                std::cerr << "Unknown option '" << arg << "'" << std::endl << "Test '" << argv[0] << " --help'" << std::endl;
                return -1;
            }
        }
    }
    else {
        std::cerr << "Missing arguments, try " << argv[0] << " --help" << std::endl;
        return -1;
    }


    if (init == true) {
        if (getuid() != 0) {
            std::cerr << "Initialization requires root!" << std::endl;
            return -1;
        }
        //std::cout << "Initialization :)" << std::endl;

        if (device == nullptr) {
            std::cerr << "Not implemented yet! use --arduino" << std::endl;
            return -1;

            const std::string path = "/dev/serial/by-path/";

            if (!fs::exists(path)) {
                std::cerr << "Serial path does not exist!" << std::endl;
                return -1;
            }

            for (const auto& p : fs::directory_iterator(path)) {

            }
        }
        else {
            int serial_port = open(device, O_RDWR | O_NOCTTY | O_NDELAY);
            if (serial_port < 0) {
                std::cerr << "Error " << errno << " opening serial port: " << strerror(errno) << std::endl;
                return -1;
            }

            struct termios tty;

            if (tcgetattr(serial_port, &tty) != 0) {
                std::cerr << "Error " << errno << " getting termios: " << strerror(errno) << std::endl;
                return -1;
            }

            cfsetispeed(&tty, B9600);
            cfsetospeed(&tty, B9600);

            tty.c_cflag &= ~PARENB;
            tty.c_cflag &= ~CSTOPB;
            tty.c_cflag &= ~CSIZE;
            tty.c_cflag |= CS8;

            tty.c_cflag &= ~CRTSCTS;

            tty.c_lflag = 0;
            tty.c_iflag = 0;
            tty.c_oflag = 0;

            tty.c_cc[VMIN] = 0;
            tty.c_cc[VTIME] = 10;

            if (tcsetattr(serial_port, TCSANOW, &tty) != 0) {
                std::cerr << "Error " << errno << " setting termios: " << strerror(errno) << std::endl;
                return -1;
            }

            const char* msg = INFO;
            int n_written = write(serial_port, msg, strlen(msg));
            if (n_written < 0) {
                std::cerr << "Write failed!" << std::endl;
            }


        }
    }


    return -1;
}

bool shortHand(const char* str, char shortHand) {
    if (str == nullptr) return false;
    if (shortHand == 0) return false;
    return startWith(str, '-') && !startsWith(str, "--") && contains(str, shortHand);
}