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

#include "intersections.h"
#include "runner.h"

static bool intersections_test_0(const char ** scenario)
{
  *scenario = "An intersection encapsulates t and object";

  struct sphere s = sphere();
  struct intersection i = intersection(3.5f, &s);

  return
    float_equal(i.t, 3.5f) &&
    i.object == &s;
}

static bool intersections_test_1(const char ** scenario)
{
  *scenario = "Aggregating intersections2";

  struct sphere s = sphere();
  struct intersection i1 = intersection(1.0f, &s);
  struct intersection i2 = intersection(2.0f, &s);
  struct intersections2 xs = intersections2(i1, i2);

  return
    xs.count == 2 &&
    float_equal(xs.i[0].t, 1.0f) &&
    float_equal(xs.i[1].t, 2.0f);
}

static bool intersections_test_2(const char ** scenario)
{
  *scenario = "The hit, when all intersections2 have positive t";

  struct sphere s = sphere();
  struct intersection i1 = intersection(1.0f, &s);
  struct intersection i2 = intersection(2.0f, &s);
  struct intersections2 xs = intersections2(i2, i1);

  struct intersection * i = hit((struct intersections *)&xs);

  return
    i != NULL &&
    i->t == i1.t &&
    i->object == i1.object;
}

static bool intersections_test_3(const char ** scenario)
{
  *scenario = "The hit, when some intersections2 have negative t";

  struct sphere s = sphere();
  struct intersection i1 = intersection(-1.0f, &s);
  struct intersection i2 = intersection( 1.0f, &s);
  struct intersections2 xs = intersections2(i2, i1);

  struct intersection * i = hit((struct intersections *)&xs);

  return
    i != NULL &&
    i->t == i2.t &&
    i->object == i2.object;
}

static bool intersections_test_4(const char ** scenario)
{
  *scenario = "The hit, when all intersections2 have negative t";

  struct sphere s = sphere();
  struct intersection i1 = intersection(-2.0f, &s);
  struct intersection i2 = intersection(-1.0f, &s);
  struct intersections2 xs = intersections2(i2, i1);

  struct intersection * i = hit((struct intersections *)&xs);

  return i == NULL;
}

static bool intersections_test_5(const char ** scenario)
{
  *scenario = "The hit is always the lowest nonnegative intersection";

  struct sphere s = sphere();
  struct intersection i1 = intersection( 5.0f, &s);
  struct intersection i2 = intersection( 7.0f, &s);
  struct intersection i3 = intersection(-3.0f, &s);
  struct intersection i4 = intersection( 2.0f, &s);
  struct intersections4 xs = intersections4(i1, i2, i3, i4);

  struct intersection * i = hit((struct intersections *)&xs);

  return
    i != NULL &&
    i->t == i4.t &&
    i->object == i4.object;
}

test_t intersections_tests[] = {
  intersections_test_0,
  intersections_test_1,
  intersections_test_2,
  intersections_test_3,
  intersections_test_4,
  intersections_test_5,
};

RUNNER(intersections_tests);