App managers: the business logic layer of Telegram Web K

// src/lib/appManagers/manager.ts
export class AppManager {
  protected appMessagesManager: AppMessagesManager;
  protected appChatsManager: AppChatsManager;
  protected appUsersManager: AppUsersManager;
  // ... all other managers
  protected rootScope: RootScope;
  protected apiManager: ApiManager;
  // ...

  public setManagersAndAccountNumber(managers: AppManagers, accountNumber: ActiveAccountNumber) {
    Object.assign(this, {...managers, accountNumber});
    this.log = this.createLogger(this.name, this.logTypes);
  }
}

// src/lib/appManagers/createManagers.ts
export default function createManagers(
  appStoragesManager: AppStoragesManager,
  stateManager: AppStateManager,
  accountNumber: ActiveAccountNumber,
  userId: UserId
) {
  const managers = {
    appMessagesManager: new AppMessagesManager,
    appChatsManager: new AppChatsManager,
    // ... all others
    authorizer: undefined as Authorizer,
    dcConfigurator: new DcConfigurator,
    timeManager: new TimeManager,
    rootScope: new RootScope,
    // ...
  };

  // Authorizer needs dcConfigurator + timeManager, so it's created after
  managers.authorizer = new Authorizer({
    timeManager: managers.timeManager,
    dcConfigurator: managers.dcConfigurator
  });

  for(const name in managers) {
    managers[name].setManagersAndAccountNumber(managers, accountNumber);
  }

  // Priority initialization: users + chats + notifications before everything else
  // then all managers' after() hooks run in parallel
  return Promise.all(afterPromises).then(() => {
    managers.rootScope.dispatchEventSingle('managers_ready');
    return managers;
  });
}

// Dispatching from a manager
this.rootScope.dispatchEvent('dialog_unread', {peerId, count});

// Listening in a UI component
rootScope.addEventListener('dialog_unread', ({peerId, count}) => {
  // update badge
});