import { Component, Node } from 'cc';

export default function Singleton<T>(componentName?: string) {
    class Singleton extends Component {
        //singleton
        private static _instance: T = null;
        public static get instance(): T {
            if (componentName && !Singleton._instance) {
                Singleton._instance = new Node(componentName).addComponent(componentName) as T;
            }
            return Singleton._instance;
        }

        protected onLoad(): void {
            Singleton._instance = this as unknown as T;
        }
    }

    return Singleton;
}