import { AssetManager } from "../asset/AssetManager";
import { Scene } from "../scene/Scene";

type Time = {
  delta:number;
  current:number;
  last:number;
}

export class Game {
  public time:Time;
  public scene:Scene|null;
  public assets:AssetManager;

  constructor() {
    this.time = { delta: 0, current: 0, last: 0 };
    this.assets = new AssetManager();
    this.scene = null;
  }

  public setScene(scene:Scene) { this.scene = scene; }

  private timeUpdate() {
    this.time.delta = epochGetDelta();
    this.time.current = epochGetCurrent();
    this.time.last = epochGetLast();
  }

  init() {
    this.timeUpdate();
  }

  update() {
    this.timeUpdate();

    if(this.scene) this.scene.update();
  }

  dispose() {
    if(this.scene) this.scene.dispose();
  }
}

// Main Game Instance
let GAME_MAIN:Game|null = null;

/**
 * Set the main game instance.
 * @param game Game to become the main game instance.
 */
export const gameSetMain = (game:Game) => {
  GAME_MAIN = game;
}

/**
 * Method that is invoked by C when the game needs to intialize.
 */
const init = () => {
  if(!GAME_MAIN) return;
  GAME_MAIN.init();
}

/**
 * Method that is invoked by C every single frame.
 */
const update = () => {
  if(!GAME_MAIN) return;
  GAME_MAIN.update();
}

/**
 * Method that is invoked by C when the game needs to stop and clean up.
 */
const dispose = () => {
  if(!GAME_MAIN) return;
  GAME_MAIN.dispose();
}