function before(fn, advice) {
  return function(...args) {
    advice.apply(this, args);
    return fn.apply(this, args);
  };
}

function after(fn, advice) {
  return function(...args) {
    const result = fn.apply(this, args);
    advice.call(this, result);
    return result;
  };
}

// 使用示例
function fetchData() {
  console.log("正在获取数据...");
  return "data";
}

const trackedFetch = before(fetchData, function() {
  console.log("开始请求");
});

const loggedFetch = after(trackedFetch, function(result) {
  console.log("请求完成，结果:", result);
});

loggedFetch();

function createAOP(target, aspects = {}) {
  return new Proxy(target, {
    get(target, prop) {
      const method = target[prop];
      if (typeof method !== 'function') return method;

      const before = aspects[`before:${prop}`];
      const after = aspects[`after:${prop}`];

      return function(...args) {
        if (before) before.apply(this, args);
        const result = method.apply(target, args);
        if (after) after.call(this, result);
        return result;
      };
    }
  });
}

// 示例使用
const service = {
  getUser(id) {
    console.log(`获取用户 ${id}`);
    return { id, name: 'Alice' };
  },
  s*eUser(user) {
    console.log(`保存用户 ${user.name}`);
    return true;
  }
};

const proxiedService = createAOP(service, {
  'before:getUser': function(id) {
    console.log('【日志】即将查询用户', id);
  },
  'after:getUser': function(user) {
    console.log('【监控】用户查询完成:', user);
  },
  'before:s*eUser': function(user) {
    console.log('【验证】正在校验用户数据');
  }
});

proxiedService.getUser(123);
// 输出：
// 【日志】即将查询用户 123
// 获取用户 123
// 【监控】用户查询完成: { id: 123, name: 'Alice' }