package unfurlers import ( "bytes" "errors" "fmt" "net/http" neturl "net/url" "regexp" "go.uber.org/zap" "github.com/status-im/status-go/images" "github.com/status-im/status-go/protocol/common" "github.com/status-im/status-go/protocol/protobuf" ) const ( maxImageSize = 1024 * 350 ) var imageURLRegexp = regexp.MustCompile(`(?i)^.+(png|jpg|jpeg|webp)$`) type ImageUnfurler struct { url *neturl.URL logger *zap.Logger httpClient *http.Client } func NewImageUnfurler(URL *neturl.URL, logger *zap.Logger, httpClient *http.Client) *ImageUnfurler { return &ImageUnfurler{ url: URL, logger: logger, httpClient: httpClient, } } func compressImage(imgBytes []byte) ([]byte, error) { smallest := imgBytes img, err := images.DecodeImageData(imgBytes, bytes.NewReader(imgBytes)) if err != nil { return nil, err } compressed := bytes.NewBuffer([]byte{}) err = images.CompressToFileLimits(compressed, img, images.DefaultBounds) if err != nil { return nil, err } if len(compressed.Bytes()) < len(smallest) { smallest = compressed.Bytes() } if len(smallest) > maxImageSize { return nil, errors.New("image too large") } return smallest, nil } // IsSupportedImageURL detects whether a URL ends with one of the // supported image extensions. It provides a quick way to identify whether URLs // should be unfurled as images without needing to retrieve the full response // body first. func IsSupportedImageURL(url *neturl.URL) bool { return imageURLRegexp.MatchString(url.Path) } // isSupportedImage returns true when payload is one of the supported image // types. In the future, we should differentiate between animated and // non-animated WebP because, currently, only static WebP can be processed by // functions in the status-go/images package. func isSupportedImage(payload []byte) bool { return images.IsJpeg(payload) || images.IsPng(payload) || images.IsWebp(payload) } func (u *ImageUnfurler) Unfurl() (common.LinkPreview, error) { preview := newDefaultLinkPreview(u.url) preview.Type = protobuf.UnfurledLink_IMAGE headers := map[string]string{"user-agent": headerUserAgent} imgBytes, err := fetchBody(u.logger, u.httpClient, u.url.String(), headers) if err != nil { return preview, err } if !isSupportedImage(imgBytes) { return preview, fmt.Errorf("unsupported image type url='%s'", u.url.String()) } compressedBytes, err := compressImage(imgBytes) if err != nil { return preview, fmt.Errorf("failed to compress image url='%s': %w", u.url.String(), err) } width, height, err := images.GetImageDimensions(compressedBytes) if err != nil { return preview, fmt.Errorf("could not get image dimensions url='%s': %w", u.url.String(), err) } dataURI, err := images.GetPayloadDataURI(compressedBytes) if err != nil { return preview, fmt.Errorf("could not build data URI url='%s': %w", u.url.String(), err) } preview.Thumbnail.Width = width preview.Thumbnail.Height = height preview.Thumbnail.DataURI = dataURI return preview, nil }