import { useCallback, useRef } from "react";

export type UseEventReturn<Data> = {
  on: (listener: (data: Data) => void) => () => void;
  emit: (data: Data) => void;
  off: (listener: (data: Data) => void) => void;
  offAll: () => void;
};

export const useEventEmitter = <Data>(): UseEventReturn<Data> => {
  const listeners = useRef(new Set<(data: Data) => void>());

  const off = useCallback((listener: (data: Data) => void) => {
    listeners.current.delete(listener);
  }, []);

  const offAll = useCallback(() => {
    listeners.current.clear();
  }, []);

  const on = useCallback(
    (listener: (data: Data) => void) => {
      listeners.current.add(listener);
      return () => off(listener);
    },
    [off],
  );

  const emit = useCallback((data: Data) => {
    if (listeners.current.size) {
      listeners.current.forEach((listener) => listener(data));
    }
  }, []);

  return {
    on,
    emit,
    off,
    offAll,
  };
};