import { useState } from "react";

type MutableRefObjectWithLiving<T> = ((newValue: T) => void) & { current: T; readonly living: T };

/**
 * This hook resembles the original `useRef` hook, but it also provides `living` property that contains a last non-null value of a ref.
 * @param initialValue - initial value of the ref
 */
export function useLivingRef<T>(initialValue: T | null): MutableRefObjectWithLiving<T | null> {
  const [ref] = useState(() => {
    let value: T | null = initialValue;
    let living: T | null = value;
    // @ts-expect-error Can't help TypeScript here
    const myRef: MutableRefObjectWithLiving<T | null> = (newValue: T) => {
      myRef.current = newValue;
    };

    Object.defineProperty(myRef, "current", {
      get: () => value,
      set: (newValue) => {
        value = newValue;
        if (newValue !== null) {
          living = newValue;
        }
      },
      enumerable: true,
    });

    Object.defineProperty(myRef, "living", {
      get: () => living,
      enumerable: true,
    });

    return myRef;
  });

  return ref;
}