import { NodePool, instantiate, Node, isValid } from "cc";
import { DetailImageItem } from "../uiitems/DetailImageItem";

export class DetailImageItemPool {
  private static _instance: DetailImageItemPool = null;
  
  private _pool: NodePool;
  private _template: Node = null;
  
  private constructor() {
    this._pool = new NodePool();
  }
  
  public static get Instance(): DetailImageItemPool {
    if (!this._instance) {
      this._instance = new DetailImageItemPool();
    }
    return this._instance;
  }
  
  public setTemplate(template: Node): void {
    this._template = template;
  }
  
  public get(): Node {
    let node: Node = null;
    
    if (this._pool.size() > 0) {
      node = this._pool.get();
    } else {
      if (this._template) {
        node = instantiate(this._template);
      }
    }
    
    if (node) {
      const item = node.getComponent(DetailImageItem);
      if (item && item.reset) {
        item.reset();
      }
    }
    
    return node;
  }
  
  public put(node: Node): void {
    if (node && isValid(node)) {
      node.removeFromParent();
      this._pool.put(node);
    }
  }
  
  public clear(): void {
    this._pool.clear();
  }
  
  public getPoolSize(): number {
    return this._pool.size();
  }
}