/**
 * Prefab对象池类
 * 1. 占用并复用资源，使用Mgr.ResMgr加载资源并标记为资源池占用
 * 2. Prefab对象管理、缓存、创建，每个Prefab资源对应一个池子
 * 3. 针对每个Prefab对象池的水位控制
 * 4. freePrefab 里面检测node是否有效，无效的node报错提示，_createCount--
 *
 * @format
 */
import {BaseUI} from '../ui/BaseUI'
import {Log} from '../utils/LogUtils'
import {Data} from '../GameControl'

export interface IPrefabPool {
    baseUI: BaseUI
    prefabReset(): void
}
export class PrefabPool {
    private _createCount: number = 0
    private _waterMark: number = 10
    private readonly _url: string
    private readonly _res: cc.Prefab = null
    private _nodes: cc.Node[] = []

    public constructor(url: string, prefab: cc.Prefab) {
        this._url = url
        this._res = prefab
    }

    /**
     * 获取url
     */
    public getUrl(): string {
        return this._url
    }

    /**
     * 获取prefab
     * @param url prefab的url
     */
    public getPrefab(): cc.Node {
        if (this._nodes.length > 0) {
            const node = this._nodes.pop()
            if (cc.isValid(node)) {
                node.active = true
                return node
            }
            node.destroy()
            this._createCount++
            return cc.instantiate(this._res)
        }
        this._createCount++
        return cc.instantiate(this._res)
    }

    /**
     * 回收prefab
     * @param url prefab的url
     * @param node
     */
    public freePrefab(node: cc.Node) {
        if (!(node && cc.isValid(node))) {
            cc.error('[ERROR] PrefabPool: freePrefab: isValid node')
            this._createCount--
            return
        }
        if (this._waterMark < this._nodes.length) {
            this._createCount--
            Log.warn('PrefabPoolManager freePrefab: waterMark is below')
            node.destroy()
        } else {
            node.stopAllActions()
            node.parent = null
            node.position = cc.Vec3.ZERO
            node.scale = 1
            const components = node['_components']
            components.forEach(value => {
                if (value['prefabReset']) {
                    value.prefabReset()
                }
            })
            this._nodes.push(node)
        }
    }

    /**
     * 设置回收池缓存个数
     * @param waterMark 缓存个数
     */
    public setWaterMark(waterMark: number) {
        if (waterMark > this._waterMark) {
            this._waterMark = waterMark
        }
    }

    /**
     * 池子里的prefab是否都没有使用
     */
    public isUnuse() {
        if (this._nodes.length > this._createCount) {
            cc.error('PrefabPool: _nodes.length > _createCount')
        }
        return this._nodes.length == this._createCount
    }

    /**
     * 清空prefab
     */
    public destroy() {
        // 清空节点、回收资源
        for (const node of this._nodes) {
            node.destroy()
        }
        this._createCount -= this._nodes.length
        this._nodes.length = 0
        cc.assetManager.releaseAsset(this._res)
    }

    // 只清理池子不回收
    public clearPool() {
        for (const node of this._nodes) {
            node.destroy()
        }
        this._createCount -= this._nodes.length
        this._nodes.length = 0
    }
}

export class PrefabPoolManager {
    private _pools: Map<string, PrefabPool> = new Map<string, PrefabPool>()
    // Prefab url loadRes时待处理的callback
    private finishCallbackMap: Map<string, any[]> = new Map<string, any[]>()
    public initPrefabPoolByPrefab(url: string, prefab: cc.Prefab, waterMark: number = 64) {
        if (!this._pools.has(url)) {
            const pool = new PrefabPool(url, prefab)
            pool.setWaterMark(waterMark)
            this._pools.set(url, pool)
        }
    }

    //初始化节点对
    public initPoolNode(poolKey: string, prefab: cc.Prefab, waterMark: number = 64) {
        let pool = Data.main.itemsPoolMap.get(poolKey)
        if (!pool) {
            pool = new cc.NodePool()
        }
        for (let i = pool.size(); i < waterMark; ++i) {
            let obj = cc.instantiate(prefab)
            pool.put(obj)
        }
        Data.main.itemsPoolMap.set(poolKey, pool)
    }

    /**
     * 获取prefab池
     * @param url prefab的url
     */
    public getPool(url: string): PrefabPool {
        return this._pools.get(url)
    }

    /**
     * 判断是不是有prefab池
     * @param url prefab的url
     */
    public hasPool(url: string) {
        return this._pools.has(url)
    }

    /**
     * 销毁prefab池
     * @param url prefab的url
     */
    public destroyPool(url: string) {
        if (this._pools.has(url)) {
            this._pools.get(url).destroy()
            this._pools.delete(url)
        }
    }
    /**
     * 初始化预设池返回实例化节点，并返回Promise
     */
    public getNodeAsync(
        url: string,
        bundle: cc.AssetManager.Bundle = cc.resources,
        waterMark: number = 64,
    ): Promise<cc.Node> {
        return new Promise((resolve, reject) => {
            if (this._pools.has(url)) {
                let pool = this._pools.get(url)
                resolve(pool.getPrefab())
            } else {
                bundle.load(url, cc.Prefab, (error, res: cc.Prefab) => {
                    let pool: PrefabPool = null
                    if (!error) {
                        pool = new PrefabPool(url, res)
                        pool.setWaterMark(waterMark)
                        this._pools.set(url, pool)
                        resolve(pool.getPrefab())
                    } else {
                        reject(null)
                    }
                })
            }
        })
    }
    public reset() {
        this.finishCallbackMap.clear()
        this._pools.forEach(value => {
            this.destroyPool(value.getUrl())
        })
    }
}