Golang Facade パターンを使用してマルチレベルの依存関係を解決する方法

package main

import "fmt"

// 定义UserService接口
type UserService interface {
    Register(username string, password string) error
    GetUser(username string) (string, error)
}

// 定义PostService接口
type PostService interface {
    Publish(username string, content string) error
}

// 定义NotificationService接口
type NotificationService interface {
    SendNotification(username string, message string) error
}

// 实现UserService接口
type UserServiceImpl struct{}

func (userService *UserServiceImpl) Register(username string, password string) error {
    fmt.Println("User registered:", username)
    return nil
}

func (userService *UserServiceImpl) GetUser(username string) (string, error) {
    fmt.Println("Getting user:", username)
    return "User Information", nil
}

// 实现PostService接口
type PostServiceImpl struct {
    userService UserService
}

func (postService *PostServiceImpl) Publish(username string, content string) error {
    _, err := postService.userService.GetUser(username)
    if err != nil {
        return err
    }
    fmt.Println("Publishing post for user:", username)
    return nil
}

// 实现NotificationService接口
type NotificationServiceImpl struct {
    userService UserService
}

func (notificationService *NotificationServiceImpl) SendNotification(username string, message string) error {
    _, err := notificationService.userService.GetUser(username)
    if err != nil {
        return err
    }
    fmt.Println("Sending notification to user:", username)
    return nil
}

// 定义Facade接口
type Facade interface {
    RegisterUser(username string, password string) error
    PublishPost(username string, content string) error
    SendNotification(username string, message string) error
}

// 实现Facade接口
type FacadeImpl struct {
    userService        UserService
    postService        PostService
    notificationService NotificationService
}

func (facade *FacadeImpl) RegisterUser(username string, password string) error {
    return facade.userService.Register(username, password)
}

func (facade *FacadeImpl) PublishPost(username string, content string) error {
    return facade.postService.Publish(username, content)
}

func (facade *FacadeImpl) SendNotification(username string, message string) error {
    return facade.notificationService.SendNotification(username, message)
}

func main() {
    facade := &FacadeImpl{
        userService:        &UserServiceImpl{},
        postService:        &PostServiceImpl{userService: &UserServiceImpl{}},
        notificationService: &NotificationServiceImpl{userService: &UserServiceImpl{}},
    }

    facade.RegisterUser("Alice", "123456")
    facade.PublishPost("Alice", "Hello world")
    facade.SendNotification("Alice", "Welcome to our platform")
}

User registered: Alice
Getting user: Alice
Publishing post for user: Alice
Getting user: Alice
Sending notification to user: Alice