func getMailConfig()

in smtp/main.go [86:144]
51 lines of code
11 McCabe index (conditional complexity)

func getMailConfig(ctx context.Context, sg notifiers.SecretGetter, spec *notifiers.Spec) (mailConfig, error) {
	delivery := spec.Notification.Delivery

	server, ok := delivery["server"].(string)
	if !ok {
		return mailConfig{}, fmt.Errorf("expected delivery config %v to have string field `server`", delivery)
	}
	port, ok := delivery["port"].(string)
	if !ok {
		return mailConfig{}, fmt.Errorf("expected delivery config %v to have string field `port`", delivery)
	}
	sender, ok := delivery["sender"].(string)
	if !ok {
		return mailConfig{}, fmt.Errorf("expected delivery config %v to have string field `sender`", delivery)
	}

	from, ok := delivery["from"].(string)
	if !ok {
		return mailConfig{}, fmt.Errorf("expected delivery config %v to have string field `from`", delivery)
	}

	ris, ok := delivery["recipients"].([]interface{})
	if !ok {
		return mailConfig{}, fmt.Errorf("expected delivery config %v to have repeated field `recipients`", delivery)
	}

	recipients := make([]string, 0, len(ris))
	for _, ri := range ris {
		r, ok := ri.(string)
		if !ok {
			return mailConfig{}, fmt.Errorf("failed to convert recipient (%v) into a string", ri)
		}
		recipients = append(recipients, r)
	}

	passwordRef, err := notifiers.GetSecretRef(delivery, "password")
	if err != nil {
		return mailConfig{}, fmt.Errorf("failed to get ref for secret field `password`: %w", err)
	}

	passwordResource, err := notifiers.FindSecretResourceName(spec.Secrets, passwordRef)
	if err != nil {
		return mailConfig{}, fmt.Errorf("failed to find Secret resource name for reference %q: %w", passwordRef, err)
	}

	password, err := sg.GetSecret(ctx, passwordResource)
	if err != nil {
		return mailConfig{}, fmt.Errorf("failed to get SMTP password: %w", err)
	}

	return mailConfig{
		server:     server,
		port:       port,
		sender:     sender,
		from:       from,
		password:   password,
		recipients: recipients,
	}, nil
}