import { _decorator, Component, find, game } from "cc";
import { Constructor } from "../core";
import { Data } from "./Data";
const { ccclass, property } = _decorator;
/**
 * 数据系统组件，常驻节点，可创建数据、获取数据、观察数据变化
 * 创建数据：g.userData = DataSystem.createData<UserData>(UserData);update方法里：DataSystem.watch(g.userData,"money") && this.moneyLabel.string = g.userData.money;
 * @author 袁浩
 */
@ccclass('DataSystem')
export class DataSystem extends Component {
    private dataMap: Map<Constructor, Data> = new Map<Constructor, Data>();
    private watchData: Map<Data, Map<PropertyKey, boolean>> = new Map<Data, Map<PropertyKey, boolean>>();
    private watchedList: Array<{ data: Data, key: PropertyKey }> = [];
    start() {
        game.addPersistRootNode(this.node);//常驻节点
        this.node.name = "DataSystem";
    }
    /**
     * 数据系统对象
     */
    private static get thisObject(): DataSystem {
        let node = find("DataSystem");
        return node && node.getComponent(DataSystem);
    }
    /**
     * 创建数据
     * @param classConstructor 数据对象类型
     * @returns 
     */
    static createData<T extends Data>(classConstructor: Constructor<T>): void {
        let data = new classConstructor(DataSystem.thisObject.onPropertyChange, DataSystem.thisObject);
        DataSystem.thisObject.dataMap.set(classConstructor, data);
        DataSystem.thisObject.watchData.set(data, new Map<string, boolean>());
    }
    /**
     * 获取数据
     * @param classConstructor 数据对象类型
     * @returns 
     */
    static getData<T extends Data>(classConstructor: Constructor<T>): T {
        return DataSystem.thisObject.dataMap.get(classConstructor) as T;
    }
    /**
     * 删除数据
     * @param classConstructor 数据对象类型
     */
    static deleteData<T extends Data>(classConstructor: Constructor<T>): void {
        DataSystem.thisObject.watchData.delete(DataSystem.thisObject.dataMap.get(classConstructor));
        DataSystem.thisObject.dataMap.delete(classConstructor);
    }
    /**
     * 观察数据，当数据产生变化时会被观察到，被观察后会在帧尾清空标记
     * 注意：在watch帧的时候，改变正在watch的属性值是不会被观察到变化的
     * @param data 数据对象
     * @param key 数据的属性名
     * @returns 
     */
    static watch(data: Data, key: PropertyKey) {
        let propertyKeyMap = DataSystem.thisObject.watchData.get(data);
        DataSystem.thisObject.watchedList.push({ data, key });
        return propertyKeyMap.get(key);
    }
    lateUpdate() {
        for (let i = 0; i < this.watchedList.length; i++) {
            const watchedData = this.watchedList[i];
            this.watchData.get(watchedData.data).set(watchedData.key, false);
        }
    }
    private onPropertyChange(data: Data, key: PropertyKey, value: any) {
        let propertyKeyMap = this.watchData.get(data);
        propertyKeyMap.set(key, true);
    }
}