interface EventDefinition {
  element: HTMLElement;
  events: string[];
  callback: any;
  passive?: boolean;
}

export type EventUnsubscribeFn = () => void;

export function attachEvents(defs: EventDefinition[]) {
  const unsubscribers = [];

  defs.forEach(def => {
    def.events.forEach(name => {
      // Register the event listener.
      def.element.addEventListener(name, def.callback, def.passive);

      // Create an unsubscribe method.
      const unsubscribe = () =>
        def.element.removeEventListener(name, def.callback);
      unsubscribers.push(unsubscribe);
    });
  });

  // Return a function that unsubscribes the entire batch at once.
  return (() =>
    unsubscribers.forEach(unsubscribe => unsubscribe())) as EventUnsubscribeFn;
}