Function validateAttachmentURL

api/pkg/validators/validator.go:184–229

(ctx context.Context, c cache.Cache, attachmentURL string)

}

func validateAttachmentURL(ctx context.Context, c cache.Cache, attachmentURL string) error {
	cacheKey := "mms-url-validation:" + attachmentURL

	if cachedVal, err := c.Get(ctx, cacheKey); err == nil {
		if cachedVal == "valid" {
			return nil
		}
		return fmt.Errorf(cachedVal)
	}

	client := &http.Client{
		Timeout: 5 * time.Second,
	}

	req, err := http.NewRequest(http.MethodHead, attachmentURL, nil)
	if err != nil {
		errMsg := fmt.Sprintf("invalid url format")
		saveToCache(ctx, c, cacheKey, errMsg)
		return fmt.Errorf(errMsg)
	}

	resp, err := client.Do(req)
	if err != nil {
		errMsg := fmt.Sprintf("could not reach the url")
		saveToCache(ctx, c, cacheKey, errMsg)
		return fmt.Errorf(errMsg)
	}
	defer resp.Body.Close()

	if resp.StatusCode < 200 || resp.StatusCode >= 400 {
		errMsg := fmt.Sprintf("url returned an error status code: %d", resp.StatusCode)
		saveToCache(ctx, c, cacheKey, errMsg)
		return fmt.Errorf(errMsg)
	}

	const maxSizeBytes = 1.5 * 1024 * 1024

	if resp.ContentLength > int64(maxSizeBytes) {
		errMsg := fmt.Sprintf("file size (%.2f MB) exceeds the 1.5 MB carrier limit", float64(resp.ContentLength)/(1024*1024))
		saveToCache(ctx, c, cacheKey, errMsg)
		return fmt.Errorf(errMsg)
	}

	saveToCache(ctx, c, cacheKey, "valid")
	return nil
}

func saveToCache(ctx context.Context, c cache.Cache, key string, value string) {
	_ = c.Set(ctx, key, value, 15*time.Minute)