#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "util/versie.h"

static void usage(FILE *f) {
  fprintf(f,
      "Gebruik: omg [-hV] [NAAM=WAARDE]... [COMMANDO]...\n"
      "\n"
      "TODO \n"
      "\n"
      "  -h          Toon deze hulptekst\n"
      "  -V          Toon versienummer\n");
}

// Returns pointer to argument array containing the variables to set and the
// command to execute and its arguments
static char** parse_options(int argc, char **argv) {
  int opt;
  while ((opt = getopt(argc, argv, "hV")) != -1) {
    switch (opt) {
      case 'h':
        usage(stdout);
        exit(0);

      case 'V':
        drukkedoos_print_versie(stdout);
        exit(0);

      case '?':
        fprintf(stderr, "omg: Ongeldige optie: -%c\n", optopt);
        usage(stderr);
        exit(1);
    }
  }

  return argv + optind;
}


int entry_omg(int argc, char **argv) {
  char **args = parse_options(argc, argv);

  while (*args != NULL) {
    if (strchr(*args, '=') == NULL) {
      break;
    }

    char *name = strtok(*args, "=");
    char *value = strtok(NULL, "=");

    if (value == NULL) {
      fprintf(stderr, "omg: geen waarde gegeven voor sleutel '%s'\n", name);
      return 1;
    }

    errno = 0;
    if (setenv(name, value, true) == -1) {
      fprintf(stderr, "omg: kon omgeving niet aanpassen: %s\n", strerror(errno));
    }

    args++;
  }

  if (*args == NULL) {
    while (*environ != NULL) {
      printf("%s\n", *environ);
      environ++;
    }

    return 0;
  }

  errno = 0;
  execvp(args[0], args);
  fprintf(stderr, "omg: kon proces niet starten: %s\n", strerror(errno));

  return 1;
}