/** @public */
export type InitFunc<O, T> = (this: O) => T;

/**
 * Define property on target, call init it when first use, them memorize
 * @public
 */
export function initOnRead<O, T extends keyof O>(target: any, propertyKey: T, init: InitFunc<O, O[T]>) {
	if (Object.hasOwn(target, propertyKey)) {
		return;
	}
	Object.defineProperty(target, propertyKey, {
		configurable: true,
		get: function (): O[T] {
			const data = init.call(this);
			delete target[propertyKey];
			target[propertyKey] = data;
			return data;
		},
		set(v: T) {
			delete target[propertyKey];
			target[propertyKey] = v;
		},
	});
}