The composable stack for building with Go

// internal/photos/repository.go
type Repository struct {
	db *gorm.DB
}

func NewRepository(conns *database.Connections) (*Repository, error) {
	db, err := conns.Default()
	if err != nil {
		return nil, err
	}
	return &Repository{db: db}, nil
}

func (r *Repository) Recent(ctx context.Context, limit int) ([]Photo, error) {
	var photos []Photo
	err := r.db.WithContext(ctx).
		Order("created_at desc").Limit(limit).Find(&photos).Error
	return photos, err
}

// internal/photos/feed.go
type Feed struct {
	cache *cache.Cache
}

func NewFeed(cache *cache.Cache) *Feed {
	return &Feed{cache: cache}
}

func (f *Feed) Trending(ctx context.Context) ([]Photo, error) {
	c := f.cache.WithContext(ctx)
	photos, ok, err := cache.Get[[]Photo](c, "photos:trending")
	if err != nil || ok {
		return photos, err
	}
	photos = rankPhotos()
	return photos, cache.Set(c, "photos:trending", photos, 5*time.Minute)
}

// internal/photos/thumbnails.go
type Thumbnails struct {
	queues *queues.Manager
}

func NewThumbnails(queues *queues.Manager) *Thumbnails {
	return &Thumbnails{queues: queues}
}

func (t *Thumbnails) Enqueue(ctx context.Context, photo Photo) error {
	payload, err := json.Marshal(ThumbnailPayload{Path: photo.Path})
	if err != nil {
		return err
	}
	job := queue.NewJob("photos:thumbnail").
		Payload(payload).OnQueue("media").Retry(3)
	_, err = t.queues.WithContext(ctx).Dispatch(job)
	return err
}

// internal/photos/publisher.go
type Publisher struct {
	bus events.Bus
}

func NewPublisher(bus events.Bus) *Publisher {
	return &Publisher{bus: bus}
}

func (p *Publisher) PhotoUploaded(ctx context.Context, photo Photo) error {
	return p.bus.WithContext(ctx).Publish(events.PhotoUploaded{
		Path:       photo.Path,
		UploadedBy: photo.OwnerID,
	})
}

// internal/photos/welcome.go
type Welcome struct {
	mailer *mail.Mailer
}

func NewWelcome(mailer *mail.Mailer) *Welcome {
	return &Welcome{mailer: mailer}
}

func (w *Welcome) Greet(ctx context.Context, user User) error {
	return w.mailer.Message().
		To(user.Email, user.Name).
		Subject("Welcome to photodrop").
		Text("Your photos have a home now.").
		Send(ctx)
}