export class ResourceManager {
  private resources: Map<string, unknown> = new Map();
  private statuses: Map<string, Promise<boolean>> = new Map();

  get<T>(name: string): T {
    if (!this.resources.has(name)) {
      throw new Error(`Resource ${name} not found`);
    }
    return this.resources.get(name) as T;
  }

  set(name: string, value: unknown) {
    if (typeof (value as EventSource).addEventListener === "function") {
      this.statuses.set(
        name,
        new Promise((resolve) => {
          const onload = () => {
            this.resources.set(name, value);
            resolve(true);
            (value as EventSource).removeEventListener("load", onload);
          };
          (value as EventSource).addEventListener("load", onload);
        }),
      );
    } else {
      console.warn("Resource added was not a loadable resource");
    }
    this.resources.set(name, value);
  }

  delete(name: string) {
    this.resources.delete(name);
  }

  ready() {
    return Promise.all(Array.from(this.statuses.values()));
  }
}