#include <getopt.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>

#include "main.h"

#include "fuel.h"
#include "help.h"
#include "test_src.h"
#include "verify_indata.h"

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

  /* PARAMETERS */

  const int correct_num_params = 3;

  /* OPTIONS */

  /* short options */
  char* shrt_opts = "htv";

  /* long options */
  struct option const long_options[] =
    {
      {"help",    no_argument, NULL, 'h'},
      {"test",    no_argument, NULL, 't'},
      {"version", no_argument, NULL, 'v'},
      {NULL, 0, NULL, 0}
    };

  /* modes */
  _Bool help_mode;
  _Bool test_mode;
  _Bool version_mode;

  /* parse options and arguments */
  int oi; // TODO: what do you need this for?
  int o;
  int oc = 0;

  while (true) {
    oi = -1;
    o = getopt_long(argc, argv, shrt_opts, long_options, &oi);

    if (o == -1) { break; }
    else { oc++; }

    switch (o) {
    case 'h': help_mode    = true;  break;
    case 't': test_mode    = true;  break;
    case 'v': version_mode = true;  break;
    default: indata_error();
    };
  }

  if (help_mode)     { help();     }
  if (test_mode)     { test_src(); }
  if (version_mode)  { version();  }

  /* verify correct number of parameters */
  number_of_params(argc, oc, correct_num_params);
  // check_arg_types(); // TODO

  /* get user indata */
  int miles_one_year_ago = atoi(argv[oc + 1]);
  int miles_today        = atoi(argv[oc + 2]);
  int liters             = atoi(argv[oc + 3]);
  sensible_indata(miles_one_year_ago, miles_today, liters);

  /* all systems ready, do compute */
  float liters_per_mile = avarage_fuel_per_mile(miles_one_year_ago,
                                                miles_today,
                                                liters);

  /* report */
  printf("average liters per mile: %.2f\n", liters_per_mile);

  /* quit */
  return 0;
}