/**
 * Copyright (c) 2026 Dominic Masters
 *
 * This software is released under the MIT License.
 * https://opensource.org/licenses/MIT
 */

#include "dusktest.h"
#include "util/memory.h"
#include "rpg/entity/entity.h"

static void testEntitiesReset(void) {
  memoryZero(ENTITIES, sizeof(ENTITIES));
}

static void testEntityPlace(
  const uint8_t index,
  const entitytype_t type,
  const vec3 position,
  const entitydir_t direction
) {
  entityInit(&ENTITIES[index], type);
  ENTITIES[index].direction = direction;
  const vec3 extents = ENTITY_PHYSICS_EXTENTS_DEFAULT;
  physicsBodyInit(&ENTITIES[index].body, position, extents);
}

static void test_entityGetFacingFindsEntityAhead(void **state) {
  testEntitiesReset();
  testEntityPlace(0, ENTITY_TYPE_PLAYER, (vec3){ 0.0f, 0.0f, 0.0f },
    ENTITY_DIR_EAST);
  testEntityPlace(1, ENTITY_TYPE_NPC, (vec3){ 1.0f, 0.0f, 0.0f },
    ENTITY_DIR_NORTH);

  entity_t *result = entityGetFacing(&ENTITIES[0], ENTITY_INTERACT_RANGE);
  assert_ptr_equal(result, &ENTITIES[1]);

  assert_int_equal(memoryGetAllocatedCount(), 0);
}

static void test_entityGetFacingIgnoresEntityBehind(void **state) {
  testEntitiesReset();
  testEntityPlace(0, ENTITY_TYPE_PLAYER, (vec3){ 0.0f, 0.0f, 0.0f },
    ENTITY_DIR_EAST);
  testEntityPlace(1, ENTITY_TYPE_NPC, (vec3){ -2.0f, 0.0f, 0.0f },
    ENTITY_DIR_NORTH);

  entity_t *result = entityGetFacing(&ENTITIES[0], ENTITY_INTERACT_RANGE);
  assert_null(result);

  assert_int_equal(memoryGetAllocatedCount(), 0);
}

static void test_entityGetFacingIgnoresEntityToSide(void **state) {
  testEntitiesReset();
  testEntityPlace(0, ENTITY_TYPE_PLAYER, (vec3){ 0.0f, 0.0f, 0.0f },
    ENTITY_DIR_EAST);
  testEntityPlace(1, ENTITY_TYPE_NPC, (vec3){ 0.0f, 3.0f, 0.0f },
    ENTITY_DIR_NORTH);

  entity_t *result = entityGetFacing(&ENTITIES[0], ENTITY_INTERACT_RANGE);
  assert_null(result);

  assert_int_equal(memoryGetAllocatedCount(), 0);
}

static void test_entityGetFacingReturnsNullWhenNothingInRange(void **state) {
  testEntitiesReset();
  testEntityPlace(0, ENTITY_TYPE_PLAYER, (vec3){ 0.0f, 0.0f, 0.0f },
    ENTITY_DIR_EAST);

  entity_t *result = entityGetFacing(&ENTITIES[0], ENTITY_INTERACT_RANGE);
  assert_null(result);

  assert_int_equal(memoryGetAllocatedCount(), 0);
}

static void test_entityGetFacingPicksNearest(void **state) {
  testEntitiesReset();
  testEntityPlace(0, ENTITY_TYPE_PLAYER, (vec3){ 0.0f, 0.0f, 0.0f },
    ENTITY_DIR_EAST);
  // Farther candidate placed at the lower array index, to prove the
  // result is chosen by distance, not array/insertion order.
  testEntityPlace(1, ENTITY_TYPE_NPC, (vec3){ 1.5f, 0.0f, 0.0f },
    ENTITY_DIR_NORTH);
  testEntityPlace(2, ENTITY_TYPE_NPC, (vec3){ 1.0f, 0.0f, 0.0f },
    ENTITY_DIR_NORTH);

  entity_t *result = entityGetFacing(&ENTITIES[0], ENTITY_INTERACT_RANGE);
  assert_ptr_equal(result, &ENTITIES[2]);

  assert_int_equal(memoryGetAllocatedCount(), 0);
}

int main(void) {
  const struct CMUnitTest tests[] = {
    cmocka_unit_test(test_entityGetFacingFindsEntityAhead),
    cmocka_unit_test(test_entityGetFacingIgnoresEntityBehind),
    cmocka_unit_test(test_entityGetFacingIgnoresEntityToSide),
    cmocka_unit_test(test_entityGetFacingReturnsNullWhenNothingInRange),
    cmocka_unit_test(test_entityGetFacingPicksNearest),
  };

  return cmocka_run_group_tests(tests, NULL, NULL);
}