Typescript access嵌套条件类型

type User = {
  id: number;
  name: string;
  isAdmin: boolean;
};

type Admin = {
  id: number;
  name: string;
  isAdmin: true;
};

type UserType<T> = T extends { isAdmin: true } ? "admin" : "user";
type Access<T> = T extends "admin" ? Admin : User;

function getUserType<T extends User>(user: T): UserType<T> {
  return user.isAdmin ? "admin" : "user";
}

function getUser<T extends User>(user: T): Access<UserType<T>> {
  if (user.isAdmin) {
    return {
      id: user.id,
      name: user.name,
      isAdmin: true,
    } as Access<UserType<T>>;
  } else {
    return {
      id: user.id,
      name: user.name,
      isAdmin: false,
    } as Access<UserType<T>>;
  }
}

const user: User = {
  id: 1,
  name: "John Doe",
  isAdmin: false,
};

const admin: Admin = {
  id: 2,
  name: "Admin",
  isAdmin: true,
};

const userType = getUserType(user);
console.log(userType); // Output: "user"

const userAccess = getUser(user);
console.log(userAccess); // Output: { id: 1, name: "John Doe", isAdmin: false }

const adminType = getUserType(admin);
console.log(adminType); // Output: "admin"

const adminAccess = getUser(admin);
console.log(adminAccess); // Output: { id: 2, name: "Admin", isAdmin: true }