active-tab.ts

import { extractHostname } from "./extract-hostname";

export class ActiveTab {
  private static instance: ActiveTab;
  private _activeTabUrl: string | null;
  private _activeTabDomain: string | null;

  constructor() {
      if (ActiveTab.instance) {
          throw new Error("Error - use ActiveTab.getInstance()");
      }
      this._activeTabUrl = null;
      this._activeTabDomain = null;
  }

  static getInstance(): ActiveTab {
    ActiveTab.instance = ActiveTab.instance || new ActiveTab();
    return ActiveTab.instance;
  }

  public setActiveTab(value:string | null): void
  {
    this._activeTabUrl = value;
    this._activeTabDomain = value != null ? extractHostname(value) : null;
  }

  public getActiveTabUrl(): string | null
  {
    return this._activeTabUrl;
  }

  public getActiveTabDomain(): string | null
  {
    return this._activeTabDomain;
  }
}