import {useCallback, useRef, useEffect} from 'react';
import {EventEmitter} from 'events';

const _EVENT = new EventEmitter();
type customEventProp = {};
type evtHandlerProp = (e: customEventProp) => void;
export function useEvent(evtName: string, handler: evtHandlerProp) {
    // 一个指向handler的指针
    const handRef = useRef<evtHandlerProp>(handler);
    // 更新handler引用
    useEffect(() => {
        handRef.current = handler;
    }, [handler]);
    // 初始化/解绑
    useEffect(() => {
        const eventListener = (evt: customEventProp) => handRef.current?.call(null, evt);
        _EVENT.addListener(evtName, eventListener);
        return () => {
            _EVENT.off(evtName, eventListener);
        };
    }, [evtName]);
}

export function useEmitter<T = customEventProp>(evtName: string) {
    const Emitter = useCallback((data: T) => _EVENT.emit(evtName, data), [evtName]);
    return Emitter;
}