#include <iostream>
#include <memory>

// 抽象组件类
class Component {
public:
    virtual ~Component() = default;
    virtual void operation() const = 0;
};

// 具体组件
class ConcreteComponent : public Component {
public:
    void operation() const override {
        std::cout << "基础功能执行\n";
    }
};

// 装饰器基类
class Decorator : public Component {
protected:
    std::shared_ptr<Component> component_;

public:
    explicit Decorator(std::shared_ptr<Component> comp) : component_(comp) {}

    void operation() const override {
        component_->operation();
    }
};

// 具体装饰器A：添加日志功能
class LoggingDecorator : public Decorator {
public:
    using Decorator::Decorator;

    void operation() const override {
        std::cout << "[日志] 开始执行操作\n";
        Decorator::operation();
        std::cout << "[日志] 操作执行完成\n";
    }
};

// 具体装饰器B：添加权限检查
class AuthDecorator : public Decorator {
public:
    using Decorator::Decorator;

    void operation() const override {
        std::cout << "[权限] 正在检查用户权限...\n";
        // 假设检查通过
        std::cout << "[权限] 权限验证通过\n";
        Decorator::operation();
    }
};

int main() {
    // 创建基础对象
    auto component = std::make_shared<ConcreteComponent>();

    // 添加日志装饰
    auto logged = std::make_shared<LoggingDecorator>(component);

    // 再添加权限装饰
    auto secured = std::make_shared<AuthDecorator>(logged);

    // 执行操作（层层调用）
    secured->operation();

    return 0;
}