//Sa se scrie un program in C care se apeleaza asa:
//<program> <dir>
//Programul principal va incepe sa traverseze recursiv directorul primit ca parametru in momentul in care
//primeste semnalul SIGUSR1. Pentru fiecare fisier intalnit care are extensia .c programul principal va
//invoca gcc astfel incat sa se vada toate warningurile. Executabilul generat va avea acelasi nume ca si
//fisierul primit, fara extensia .c (file.c => file)

//Pentru fiecare fisier care are extensia .txt, programul principal va invoca un al doilea program care va
//-procesa fisierul primit si va scrie la standard out, urmatoarele informatii:
  //  numarul de linii, respectiv nr de caractere (program in C sau shell)
//-procesa outputul de la gcc, respectiv de la al doilea program, folosindu-se de un pipe,iar la final va scrie numarul total de linii si nr total de caractere

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <signal.h>
#include <string.h>
#include <dirent.h>

int semnal = 0;
int pfd1[2];
pid_t pid;

void handler(int signum)
{
    semnal = 1;
}

void traverseaza(char *path)
{
    if ((pid = fork()) < 0)
    {
        printf("eroare fork\n");
        exit(EXIT_FAILURE);
    }

    if (pid == 0)
    {
        char buff[1024];
        int i, r;

        close(pfd1[1]);

        while ((r = read(pfd1[0], buff, sizeof(buff))))
        {
            buff[r] = '\0';
            printf("%s", buff);
        }

        close(pfd1[0]);
        exit(0);
    }
    else
    {
        DIR *d = opendir(path);

        if (d == NULL)
            exit(EXIT_FAILURE);

        struct dirent *dir;
        char newpath[512];

        while ((dir = readdir(d)) != NULL)
        {
            if (!strcmp(dir->d_name, ".") || !strcmp(dir->d_name, ".."))
                continue;

            sprintf(newpath, "%s/%s", path, dir->d_name);

            struct stat st;

            if (stat(newpath, &st) < 0)
                exit(EXIT_FAILURE);

            if (S_ISREG(st.st_mode))
            {
                if (strstr(dir->d_name, ".c") != NULL)
                {
                    char *file_name = strtok(dir->d_name, ".c");

                    if (file_name != NULL)
                    {
                        close(pfd1[0]);
                        dup2(pfd1[1], 1);
                        close(pfd1[1]);

                        execlp("gcc", "gcc", "-Wall", "-o", file_name, newpath, NULL);
                        printf("eroare execlp\n");

                        exit(EXIT_FAILURE);
                    }
                }
                else if (strstr(dir->d_name, ".txt") != NULL)
                {
                    close(pfd1[0]);
                    dup2(pfd1[1], 1);
                    close(pfd1[1]);

                    execlp("wc", "wc", "-lm", newpath, NULL);
                    printf("Eroare execlp\n");

                    exit(EXIT_FAILURE);
                }
            }
        }

        closedir(d);
    }
}

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

    if (argc != 2)
    {
        printf("Usage %s <dir>\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    if (pipe(pfd1) < 0)
        exit(EXIT_FAILURE);

    struct sigaction sa;

    sa.sa_handler = handler;
    sigaction(SIGUSR1, &sa, NULL);

    while (!semnal) {
        printf("waiting for signal\n");
        sleep(1);
    }

    traverseaza(argv[1]);

    if (wait(&status) < 0)
    {
        printf("error\n");
        exit(EXIT_FAILURE);
    }

    printf("status %d\n", WEXITSTATUS(status));

    return 0;
}