RecaptchaService Go Implementation

recaptcha.go

package recaptcha

var ErrResponseEmpty = errors.New("response is an empty string")

const siteVerifyURL = "https://www.google.com/recaptcha/api/siteverify"

type (
	V3Response struct {
		ChallengeTS time.Time `json:"challenge_ts"`
		Hostname    string    `json:"hostname"`
		ErrorCodes  []string  `json:"error-codes"`
		Success     bool      `json:"success"`
	}

	Interface interface {
		Verify(ctx context.Context, response string, remoteIP string) (V3Response, error)
	}

	Service struct {
		logger zerolog.Logger
		client *http.Client
		secret string
	}
)

func New(secret string, logger zerolog.Logger) *Service {
	return &Service{
		logger: logger,
		secret: secret,
		client: &http.Client{},
	}
}

var _ Interface = &Service{}

func (s Service) Verify(ctx context.Context, response string, remoteIP string) (V3Response, error) {
	if response == "" {
		return V3Response{}, ErrResponseEmpty
	}

	form := url.Values{
		"secret":   {s.secret},
		"response": {response},
	}

  if len(remoteIP) > 0 {
		form.Set("remoteip", remoteIP)
	}

	req, err := http.NewRequestWithContext(ctx, http.MethodPost, siteVerifyURL, strings.NewReader(form.Encode()))
	if err != nil {
		return V3Response{}, fmt.Errorf("failed to create reCAPTCHA V3 request: %w", err)
	}
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")

	resp, err := s.client.Do(req) //nolint:bodyclose
	if err != nil {
		return V3Response{}, fmt.Errorf("failed to perform reCAPTCHA V3 request: %w", err)
	}

	defer func(Body io.ReadCloser) {
		if err = Body.Close(); err != nil {
			s.logger.Err(err).Msg("Error while closing response")
		}
	}(resp.Body)

	var r V3Response
	if err = json.NewDecoder(resp.Body).Decode(&r); err != nil {
		return V3Response{}, err
	}

	return r, nil
}