package system import ( "context" "errors" "strings" ) type EmailRepo interface { Send(context.Context, []string, string, string) error DefaultRecipients() []string } type EmailUsecase struct{ repo EmailRepo } func NewEmailUsecase(repo EmailRepo) *EmailUsecase { return &EmailUsecase{repo: repo} } func (uc *EmailUsecase) Send(ctx context.Context, to, subject, body string) error { return uc.repo.Send(ctx, strings.Split(to, ","), subject, body) } func (uc *EmailUsecase) Test(ctx context.Context) error { recipients := uc.repo.DefaultRecipients() if len(recipients) == 0 { return errors.New("未配置测试邮件收件人") } return uc.repo.Send(ctx, recipients, "test", "test") }