import Singleton from '../Base/Singleton'
import { instantiate, Node, Prefab } from 'cc'
import { EntityTypeEnum } from '../Enum'
import DataManager from './DataManager'
import { ResourceManager } from './ResourceManager'

export default class ObjectPoolManager extends Singleton {
  static get Instance() {
    return super.GetInstance<ObjectPoolManager>()
  }

  private objectPool: Node = null
  private poolObjectMap: Map<EntityTypeEnum, Node[]> = new Map()

  private getObjectContainerName(objectName: EntityTypeEnum) {
    return objectName + 'Pool'
  }

  getPoolObject(objectName: EntityTypeEnum) {
    if (this.objectPool === null) {
      this.objectPool = new Node("ObjectPool")
      this.objectPool.setParent(DataManager.Instance.gm.stage)
    }

    if (!this.poolObjectMap.has(objectName)) {
      this.poolObjectMap.set(objectName, [])
      const container = new Node(this.getObjectContainerName(objectName))
      container.setParent(this.objectPool)
    }

    let node: Node
    const nodes = this.poolObjectMap.get(objectName)
    const index = nodes.findIndex(node => node.active)

    if (index === -1) {
      const prefab = DataManager.Instance.prefabMap.get(objectName)
      node = instantiate(prefab)
      node.name = objectName
      node.setParent(this.objectPool.getChildByName(this.getObjectContainerName(objectName)))
    } else {
      node = nodes.splice(index, 1)[0]
    }
    node.active = true
    return node
  }

  returnPoolObject(object: Node) {
    object.active = false
    const objectName = object.name as EntityTypeEnum
    this.poolObjectMap.get(objectName).push(object)
  }
}