#include<iostream>
#include<list>

class Subject;

//观察员基类
class Observer {
public:
    //绑定到被观察员
    Subject* subject;
    virtual void Update() = 0;
};

//被观察员
class Subject {
    std::list<Observer*> observers;
    std::string message;
public:
    //得到状态
    std::string GetMessage() {
        return message;
    }

    //设置状态
    void SetMessage(std::string s) {
        message = s;
        //状态发生改变通知所有观察员
        NotifyAllObservers();
    }

    void Attach(Observer* ob) {
        //添加观察员
        observers.push_back(ob);
    }

    //通知所有观察员
    void NotifyAllObservers() {
        for (auto& obs : observers) {
            obs->Update();
        }
    }

};



//路灯王
class Observer_Archer :public Observer {
public:
    Observer_Archer(Subject* sjt) {
        subject = sjt;
    }
    //ea
    void Update()override {
        //得到通知后执行细节。。。
        if (subject->GetMessage() == "open ea !") {
            std::cout << "The star of breaking new ground !" << std::endl;
        }
        else {
            std::cout << "杂修!" << std::endl;
        }
    }
};

//红A
class Observer_RedArcher :public Observer {
public:
    Observer_RedArcher(Subject* sjt) {
        subject = sjt;
    }
    //无限剑制
    void Update()override {
        //得到通知后执行细节。。。
        if (subject->GetMessage() == "open unlimited blade works") {
            std::cout << "My whole life was unlimited blade works !" << std::endl;
        }
        else {
            std::cout << "真是麻烦啊!" << std::endl;
        }
    }

};

//阿尔托莉雅
class Observer_Saber :public Observer {
public:
    Observer_Saber(Subject* sjt) {
        subject = sjt;
    }
    //圣剑
    void Update()override {
        //得到通知后执行细节。。。
        if (subject->GetMessage() == "open excalibur") {
            std::cout << "Excalibur" << std::endl;
        }
        else {
            std::cout << "是你在召唤我吗!" << std::endl;
        }
    }
};
int main()
{
    //创建被观察员
    Subject* subject = new Subject();
    //召唤金闪闪
    Observer* ob_archer = new Observer_Archer(subject);
    //召唤红A
    Observer* ob_redArcher = new Observer_RedArcher(subject);
    //召唤saber
    Observer* ob_saber = new Observer_Saber(subject);

    //建立契约
    subject->Attach(ob_archer);
    subject->Attach(ob_redArcher);
    subject->Attach(ob_saber);

    std::string message[3]{ "open ea !","open unlimited blade works","open excalibur"};
    
    for (auto& s : message) {
        subject->SetMessage(s);
        std::cout << "\n";
    }

    system("pause");
    return 0;

}