#include <simloop.h>

#include <test.h>
#include <timer.h>

/// An initial render should always trigger on frame 0.
TEST_CASE(simloop_initial_render) {
  constexpr int UPDATE_FPS = 10;

  Timer      timer   = {};
  Simloop    simloop = simloop_make(&(SimloopArgs){
         .update_fps = UPDATE_FPS, .max_render_fps = 0, .timer = &timer});
  SimloopOut simout;

  simloop_update(&simloop, &simout);
  TEST_TRUE(simout.should_render);
}

/// A simulation loop with no render frame cap.
TEST_CASE(simloop_test_no_render_frame_cap) {
  constexpr int    UPDATE_FPS   = 10;
  const time_delta STEP         = sec_to_time_delta(1);
  const time_delta SIM_TIME_SEC = sec_to_time_delta(30);

  Timer      timer   = {};
  Simloop    simloop = simloop_make(&(SimloopArgs){
         .update_fps = UPDATE_FPS, .max_render_fps = 0, .timer = &timer});
  SimloopOut simout;

  for (time_delta t = STEP; t < SIM_TIME_SEC; t += STEP) {
    timer_advance(&timer, t);
    simloop_update(&simloop, &simout);
    TEST_TRUE(simout.should_render);
    TEST_EQUAL(simout.updates_pending, UPDATE_FPS);
  }
}

/// A simulation loop with a render frame cap.
TEST_CASE(simloop_test_with_render_frame_cap) {
  constexpr int    UPDATE_FPS    = 10;
  constexpr int    RENDER_FPS    = 5;
  const time_delta STEP          = sec_to_time_delta(0.1);
  const time_delta SIM_TIME_SEC  = sec_to_time_delta(30);
  const time_delta EXPECT_UPDATE = sec_to_time_delta(1.0 / (double)UPDATE_FPS);
  const time_delta EXPECT_RENDER = sec_to_time_delta(1.0 / (double)RENDER_FPS);

  Timer      timer   = {};
  Simloop    simloop = simloop_make(&(SimloopArgs){
         .update_fps = UPDATE_FPS, .max_render_fps = 0, .timer = &timer});
  SimloopOut simout;

  for (time_delta t = STEP; t < SIM_TIME_SEC; t += STEP) {
    timer_advance(&timer, t);
    simloop_update(&simloop, &simout);
    TEST_TRUE(((STEP % EXPECT_RENDER) == 0) ? simout.should_render : true);
    TEST_TRUE(((STEP % EXPECT_UPDATE) == 0) ? simout.updates_pending : true);
  }
}

int main() { return 0; }