#include <stdio.h>
#include <string.h>

#define INPUTLEN 5

/* This program asks the user for one of three actions: push, pull or turn.
   It then does those actions and spits out a result in degrees, of where
   the arrows on three concentric circles are pointing.
   North is 0 degrees; East is 90 degrees, etc.
*/

/* function prototypes */
void push(int *outer, int *inner);
void pull(int *outer, int *middle);
void turn(int *outer, int *middle);
int smallnums(int degrees);

int main(int argc, char *argv[])
{
   char input_s[INPUTLEN];
   int outer = 0;
   int middle = 90;
   int inner = 270;

   while (1)
   {
      printf("\npush, pull or turn the angel? ");

      /* read in 4 characters from the keyboard */
      if (strcasecmp(fgets(input_s, INPUTLEN, stdin), "\n")==0)
      {
         fgets(input_s, INPUTLEN, stdin);
      }

      printf("\nYou inputted: %s\n", input_s);

      /* figure out what the user wants to do, and do it */
      if (strcasecmp("push", input_s)==0)
      {
         push(&outer, &inner);
      }
      else if (strcasecmp("pull", input_s)==0)
      {
         pull(&outer, &middle);
      }
      else if (strcasecmp("turn", input_s)==0)
      {
         turn(&outer, &middle);
      }

      /* print the result */
      printf("\nOuter: %i | Middle: %i | Inner: %i\n", outer, middle, inner);
      printf("\n-------------------------------\n");
   }
   return 0;
}


void push(int *outer, int *inner)
{
   printf("\nIn push(); outer is %i, inner is %i\n", *outer, *inner);

   *inner = *inner + 90;
   *outer = *outer - 90;

   /* let's keep the numbers in the smaller degrees */
   *inner = smallnums(*inner);
   *outer = smallnums(*outer);

   return;
}

void pull(int *outer, int *middle)
{
   printf("\nIn pull(); outer is %i, middle is %i\n", *outer, *middle);

   *middle = *middle - 180;
   *outer = *outer + 90;

   /* smaller degrees! */
   *middle = smallnums(*middle);
   *outer = smallnums(*outer);

   return;
}

void turn(int *outer, int *middle)
{
   printf("\nIn turn(); outer is %i, middle is %i\n", *outer, *middle);

   *outer = *outer + 180;
   *middle = *middle - 90;

   /* smaller degrees */
   *outer = smallnums(*outer);
   *middle = smallnums(*middle);

   return;
}

int smallnums(int degrees)
{
   if (degrees >= 360 || degrees <= -360)
   {
      degrees = degrees / 360;
   }
   if (degrees == 1 || degrees == -1)
   {
      degrees = 0;
   }
   return degrees;
}