/*********************************************

This is a simple progrma to illustrate how to 
define a function that takes in an object as
input and returns an object as output.

*********************************************/

#include <stdio.h>

// note that the structure date is defined in
// the header file.
#include "increment_date.h"

struct date increment_date(struct date d1)
{
  struct date result;

  result = d1;
  // note that result = d1 is the same as the following three lines:
  //result.day = d1.day;
  //result.month = d1.month;
  //result.year = d1.year;

  result.day++;
  switch(result.month)
  {
  case 1:
  case 3:
  case 5:
  case 7:
  case 8:
  case 10:
  case 12:
    if (result.day == 32)
    {
      result.day = 1;
      result.month++;
    }
    break;

  case 2:
    if (result.day == 29)
    {
      result.day = 1;
      result.month++;
    }
    break;

  default:
    if (result.day == 30)
    {
      result.day = 1;
      result.month++;
    }
  }

  if (result.month == 13)
  {
    result.month = 1;
    result.year++;
  }

  return result;
}


int main(void)
{
  /* date 1 */
  struct date d1;
  d1.year = 2008;
  d1.month = 3;
  d1.day = 10;

  struct date d2 = increment_date(d1);
  printf("d1 = %d/%d/%d\n", d1.month, d1.day, d1.year);
  printf("d2 = %d/%d/%d\n", d2.month, d2.day, d2.year);
}