import { EventEmitter } from "eventemitter3";

import { MetapageEvents } from "./events.js";
import { JsonRpcMethodsFromParent } from "./jsonrpc.js";
import { MetapageDefinition } from "./v2/index.js";

export enum MetapageHashParams {
  mp_debug = "mp_debug",
}

export const isIframe = (): boolean => {
  //http://stackoverflow.com/questions/326069/how-to-identify-if-a-webpage-is-being-loaded-inside-an-iframe-or-directly-into-t
  try {
    return window !== window.top;
  } catch (ignored) {
    return false;
  }
};

export const INITIAL_NULL_METAPAGE_DEFINITION: MetapageDefinition = {
  metaframes: {},
};

export class MetapageShared extends EventEmitter<
  MetapageEvents | JsonRpcMethodsFromParent
> {
  // Easier to ensure this value is never null|undefined
  _definition: MetapageDefinition = INITIAL_NULL_METAPAGE_DEFINITION;

  constructor() {
    super();
    this.getDefinition = this.getDefinition.bind(this);
  }

  public error(err: any) {
    throw "Subclass should implement";
  }
  public getDefinition(): MetapageDefinition {
    return this._definition;
  }
}