#include "app/app.h"

namespace app {
void App::exit() {
  running = false;
}

void App::switch_to_scene(uint64_t scene_id) {
  scene_pool.release(current_scene_id);
  scene_pool.use(scene_id);
  current_scene_id = scene_id;
}

App::App(Vec2<float> size, const char *title) {
  window.update(size, title);
  Scene *loading_scene = new Scene{};
  current_scene_id = scene_pool.acquire(loading_scene);
}

void App::set_fps(float fps) {
  this->fps = fps;
  target_frame_time = 1e9 / fps;
}

uint64_t App::get_fps() const {
  return fps;
}

void App::loop() {
  uint64_t frame_start = window.get_time();
  uint64_t frame_end = window.get_time();
  uint64_t previous_frame_end = 0;

  while (running) {
    frame_start = window.get_time();
    uint64_t frame_time = frame_start - frame_end;

    if (frame_time <= target_frame_time) {
      struct timespec req;
      req.tv_sec = 0;
      req.tv_nsec = target_frame_time - frame_time;
      nanosleep(&req, nullptr);
    }

    previous_frame_end = frame_end;
    frame_end = window.get_time();

    float dt = frame_end - previous_frame_end;

    Scene *scene = scene_pool[current_scene_id];

    pressed_keys.clear();
    released_keys.clear();
    scroll = {0, 0};
    text = "";

    Event e;
    while (window.poll(e)) {
      switch (e.type) {
      case Event::QUIT:
        running = false;
        break;
      case Event::MOUSE_BUTTON_DOWN:
        scene->click(e.mouse_button.position);
        down_keys[e.mouse_button.button] = true;
        pressed_keys.push_back(e.mouse_button.button);
        break;
      case Event::MOUSE_BUTTON_UP:
        down_keys[e.mouse_button.button] = false;
        released_keys.push_back(e.mouse_button.button);
        break;
      case Event::MOUSE_MOVE:
        mouse_position = e.mouse_move.position;
        break;
      case Event::MOUSE_LEAVE:
        mouse_position = {-1, -1};
        break;
      case Event::KEY_DOWN:
        down_keys[e.key.key] = true;
        pressed_keys.push_back(e.key.key);
        break;
      case Event::KEY_UP:
        down_keys[e.key.key] = false;
        released_keys.push_back(e.key.key);
        break;
      case Event::SCROLL:
        scroll = e.scroll;
        break;
      case Event::TEXT_INPUT:
        text += *e.text_input;
        delete e.text_input;
        break;
      default:
        break;
      }
    }

    int ai = mrb_gc_arena_save(Ruby::mrb);
    mrb_value dt_val = mrb_float_value(Ruby::mrb, dt / 1e9);
    update.call(1, &dt_val);
    scene->update_scene(dt_val);
    mrb_gc_arena_restore(Ruby::mrb, ai);

    scene->render(window.get_time());

    window.render();

    window.clear();
  }
}
} // namespace app