/**
 * utest_index_of_largest.c - unit tests for the largest procedure.
 */

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include "array_utils.h"


// +-----------+------------------------------------------------------
// | Constants |
// +-----------+

/** The size of the array we use for testing. */
#define SIZE 16


// +-----------+------------------------------------------------------
// | Variables |
// +-----------+

/**
 * A count of errors.
 */
static int errors = 0;


// +---------+--------------------------------------------------------
// | Helpers |
// +---------+

/**
 * A quick test of largest.
 */
static void
test_index_of_largest_helper (int a[], int limit, int expected)
{
  int result = index_of_largest (a, limit);
  if (result != expected)
    {
      printf ("Expected %d as index of largest, but found %d.\n", expected, result);
      ++errors;
    }
} // test_index_of_largest_helper

/**
 * Lots of tests of largest.  Uses def as the value everywhere in the
 * array except for where it puts large.
 */
static void
test_index_of_largest (int a[], int limit, int def, int large)
{
  int i;

  // Set up the array
  for (i = 0; i < limit; i++)
    a[i] = def;

  // Try each of the position in the array
  for (i = 0; i < limit; i++)
    {
      a[i] = large;
      test_index_of_largest_helper (a, limit, i);
      a[i] = def;
    }
} // test_index_of_largest


// +------+-----------------------------------------------------------
// | Main |
// +------+

int
main ()
{
  int values[SIZE];
  int i;

  test_index_of_largest (values, SIZE, 0, 1);
  test_index_of_largest (values, SIZE, INT_MIN, INT_MIN+1);
  test_index_of_largest (values, SIZE, INT_MAX-1, INT_MAX);

  if (errors)
    {
      printf ("%d errors encountered.\n", errors);
      return EXIT_FAILURE;
    }
  else
    {
      return EXIT_SUCCESS;
    }
} // main