/** WARNING: This code is fresh and potentially isn't correct yet. */

#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include "dbg.h"

#define MAX_DATA 100

int read_string(char **out_string, int max_buffer)
{
  *out_string = calloc(1, max_buffer + 1);
  check_mem(*out_string);

  char *result = fgets(*out_string, max_buffer, stdin);
  check(result != NULL, "Input error.");

  return 0;

error:
  if(*out_string) free(*out_string);
  *out_string = NULL;
  return -1;
}

int read_int(int *out_int)
{
  char *input = NULL;
  int rc = read_string(&input, MAX_DATA);
  check(rc == 0, "Failed to read number.");

  *out_int = atoi(input);

  free(input);
  return 0;

error:
  if(input) free(input);
  return -1;
}

int read_scan(const char *fmt, ...)
{
  int i = 0;
  int rc = 0;
  int *out_int = NULL;
  char *out_char = NULL;
  char **out_string = NULL;
  int max_buffer = 0;

  va_list argp;
  va_start(argp, fmt);

  for(i = 0; fmt[i] != '\0'; i++) {
    if(fmt[i] == '%') {
      i++;
      switch(fmt[i]) {
        case '\0':
          sentinel("Invalid format, you ended with %%.");
          break;

        case 'd':
          out_int = va_arg(argp, int *);
          rc = read_int(out_int);
          check(rc == 0, "Failed to read int.");
          break;

        case 'c':
          out_char = va_arg(argp, char *);
          *out_char = fgetc(stdin);
          break;

        case 's':
          max_buffer = va_arg(argp, int);
          out_string = va_arg(argp, char **);
          rc = read_string(out_string, max_buffer);
          check(rc == 0, "Failed to read string.");
          break;

        default:
          sentinel("Invalid format.");

      }
    } else {
      fgetc(stdin);
    }

    check(!feof(stdin) && !ferror(stdin), "Input error.");
  }

  va_end(argp);
  return 0;

error:
  va_end(argp);
  return -1;
}



int main(int argc, char *argv[])
{
  char *first_name = NULL;
  char initial = ' ';
  char *last_name = NULL;
  int age = 0;

  printf("What's your first name? ");
  int rc = read_scan("%s", MAX_DATA, &first_name);
  check(rc == 0, "Failed first name.");

  printf("What's your initial? ");
  rc = read_scan("%c\n", &initial);
  check(rc == 0, "Failed initial.");

  printf("What's your last name? ");
  rc = read_scan("%s", MAX_DATA, &last_name);
  check(rc == 0, "Failed last name.");

  printf("How old are you? ");
  rc = read_scan("%d", &age);

  printf("---- RESULTS ----\n");
  printf("First Name: %s", first_name);
  printf("Initial: '%c'\n", initial);
  printf("Last Name: %s", last_name);
  printf("Age: %d\n", age);

  free(first_name);
  free(last_name);
  return 0;
error:
  return -1;
}