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

#include <libdaemon/dlog.h>
#include <libdaemon/dsignal.h>

#include "exec.h"

int log_exec(const char *dir, const char *prog, const char *arg) {
    pid_t pid;
    int p[2];
    unsigned n = 0;
    static char buf[256];
    int sigfd, r;
    fd_set fds;

    daemon_log(LOG_INFO, "Running '%s %s'", prog, arg);
    
    if (pipe(p) < 0) {
        daemon_log(LOG_ERR, "pipe() failed: %s", strerror(errno));
        return -1;
    }

    if ((pid = fork()) < 0) {
        daemon_log(LOG_ERR, "fork() failed: %s", strerror(errno));
        return -1;
            
    } else if (pid == 0) {
        dup2(p[1], 1);
        dup2(p[1], 2);
        
        if (p[0] > 2)
            close(p[0]);

        if (p[1] > 2)
            close(p[1]);

        close(0);
        open("/dev/null", O_RDONLY);

	umask(0022); // Set up a sane umask

        if (dir && chdir(dir) < 0) {
            daemon_log(LOG_WARNING, "Failed to change to directory '%s'", dir);
            chdir("/");
        }

        execl(prog, prog, arg, 0);

        daemon_log(LOG_ERR, "execl(%s) failed: %s\n", prog, strerror(errno));
        
        _exit(EXIT_FAILURE);
    }

    close(p[1]);

    FD_ZERO(&fds);
    FD_SET(p[0], &fds);
    FD_SET(sigfd = daemon_signal_fd(), &fds);

    n = 0;

    for (;;) {
        fd_set qfds = fds;

        if (select(FD_SETSIZE, &qfds, NULL, NULL, NULL) < 0) {

            if (errno == EINTR)
                continue;

            daemon_log(LOG_ERR, "select() failed: %s", strerror(errno));
            return -1;
        }


        if (FD_ISSET(p[0], &qfds)) {
            char c;

            if (read(p[0], &c, 1) != 1)
                break;

            buf[n] = c;
            
            if (c == '\n' || n >= sizeof(buf) - 2) {
                if (c != '\n') n++;
                buf[n] = 0;

                if (buf[0]) 
                     daemon_log(LOG_INFO, "client: %s", buf); 
            
                n = 0;
            } else
                n++;
        }

        if (FD_ISSET(sigfd, &qfds)) {
            int sig;
            
            if ((sig = daemon_signal_next()) < 0) {
                daemon_log(LOG_ERR, "daemon_signal_next(): %s", strerror(errno));
                break;
            }

            if (sig != SIGCHLD) {
                daemon_log(LOG_WARNING, "Killing child.");
                kill(pid, SIGTERM);
            }
                
            break;
        }
    }

    if (n > 0) {
        buf[n] = 0;
         daemon_log(LOG_WARNING, "client: %s", buf); 
    }

    waitpid(pid, &r, 0);

    close(p[0]);

    if (!WIFEXITED(r) || WEXITSTATUS(r) != 0) {
        daemon_log(LOG_ERR, "Program execution failed, return value is %i.", WEXITSTATUS(r));
        return -1;
    } else {
        daemon_log(LOG_INFO, "Program executed successfully.");
        return 0;
    }
}