// Bakalarska prace 2017
// Sledování cloveka robotem
// Frantisek Brandstyl
// brandfra@fel.cvut.cz

// Tento program slouzi k propojeni lokalizacniho a ridiciho programu. Vytvari dva procesy propojene pres pipe. Jeden proces ma na pipe presmerovany vstup a druhy vystup. V prvnim procesu se spousti WhyCon, ve druhem sledovaci algoritmus. Vsechny programy se ukoncuji stiskem Enter.

#include <stdio.h>
#include <stdbool.h>
#include <unistd.h>
#include <time.h>
#include <stdlib.h>
#include <signal.h>

int main(int argc, const char* argv[])
{
    fputs("Program has started.\n", stderr);

    int pipefd[2];
    pid_t whyConChild;
    pid_t controlChild;

    if (pipe(pipefd) == -1)
    {
        fputs("Creating pipe failed!\n", stderr);
        exit(EXIT_FAILURE);
    }

    whyConChild = fork();
    if (whyConChild == -1)
    {
        fputs("Creating whyConChild failed!\n", stderr);
        exit(EXIT_FAILURE);
    }

    if (whyConChild == 0)
    { // WhyCon zapisuje do pipe
        close(pipefd[0]);

        if (dup2(pipefd[1], STDOUT_FILENO) == -1)
        {
            fputs("Redirecting whyConChild output failed!\n", stderr);
            exit(EXIT_FAILURE);
        }

        // spusteni programu WhyCon
        if (execl("../whycon-master/build/whycon", "whycon", "-c", "1", "-o", "vystup1", "-x",
                  "../whycon-master/build/calibration.xml", "-t", "1", "-n", "--no-video",
                  "--width", "1280", "--height", "720", NULL)
                == -1)
        {
            fputs("Executing the WhyCon failed!\n", stderr);
            exit(EXIT_FAILURE);
        }
    }
    else
    { // vytvari se dalsi proces
        controlChild = fork();
        if (controlChild == -1)
        {
            fputs("Creating controlChild failed!\n", stderr);
            exit(EXIT_FAILURE);
        }

        if (controlChild == 0)
        { // rizeni cte z pipe
            close(pipefd[1]);

            if (dup2(pipefd[0], STDIN_FILENO) == -1)
            {
                fputs("Redirecting controlChild input failed!\n", stderr);
                exit(EXIT_FAILURE);
            }


            // spusteni programu control
            if (execl("../Aria/examples/controlV2", "controlV2", "-robotPort", "/dev/ttyUSB0", NULL)
                    == -1)
            {
                fputs("Executing the control failed!\n", stderr);
                exit(EXIT_FAILURE);
            }
            
        }
        else
        { // ukonceni programu
            close(pipefd[0]);
            close(pipefd[1]);
            while (getchar() != '\n');
            kill(whyConChild, SIGTERM);
            kill(controlChild, SIGTERM);
            wait(NULL);
        }
    }
    return 0;
}