class Assets {
  #images: Record<string, HTMLImageElement>;

  constructor() {
    this.#images = {};
  }

  isLoaded(): boolean {
    // you could use this, if so inclined, to check if a certain
    // list of assets had been loaded prior to game start
    //
    // (to do so, you would call getImage() for each desired asset
    //  and then wait for isLoaded to return true)
    for (let filename in this.#images) {
      if (!this.#images[filename].complete) {
        return false
      }
    }

    return true;
  }

  getImage(filename: string): HTMLImageElement {
    let element: HTMLImageElement;
    if (this.#images[filename]) {
      element = this.#images[filename];
    } else {
      element = document.createElement("img");
      element.src = filename;
      this.#images[filename] = element;
    }
    return element
  }
}

let active: Assets = new Assets();

export function getAssets(): Assets {
  return active;
}