/**
 * ES6
 * 代理通常可以修改某些操作的默认行为,这样我们就可以在访问默认对象之前做一层拦截
 * 通过代理通常可以监听一个对象的属性变化
 */
export class ProxyExample {
    execute() {
        class B {
            hp: number = 10;
            mp: number = 100;
        }
        let target = {};
        let handler = {
            get: (target: any, p: PropertyKey, receiver: any) => {
                if (p === "toString") {
                    return '[TAEGET-toString:]' + target.toString();
                } else {
                    return target[p];
                }
            },
            set: (target: any, p: PropertyKey, value: any, receiver: any) => {
                try {
                    let oldValue = target[p];
                    if (oldValue !== value) {
                        console.log(`值从${oldValue},变成:${value}`);
                        target[p] = value;
                    }
                } catch{

                }

                return true;
            }
        };

        let _b = new B();

        let p = new Proxy(target, handler);
        // p.o = new B();
        // p.o = 1;
        // p.o = 1;
        // p.o = true;
        // p.o = true;
        // p.o = _b;
        // p.o = _b;
        // console.log(p.toString);
        // var object: any = { proxy: new Proxy(target, handler) };
        let obj = Object.create(p);
        obj.o = new B();
        obj.o = 1;
        obj.o = 1;
        obj.o = true;
        obj.o = true;
        obj.o = _b;
        obj.o = _b;
        console.log(obj.toString);

        //-----------用于判断拦截某个属性的读取操作-----------------//
        let proxy = new Proxy(_b, {
            get: function (target, p: PropertyKey) {
                if (p in target) {
                    return target[p];
                } else {
                    throw new ReferenceError(`属性:${p}不存在！！`);
                }
            }
        });
        // proxy['height'];


        // Proxying a function object
        let target1 = function () { return 'I am the target'; };
        let handler1 = {
            apply: (receiver, ...args) => {
                return 'I am the proxy';
            }
        };

        let p1 = new Proxy(target1, handler1);
        p1() === 'I am the proxy';
    }
}