107 lines
3.1 KiB
Go
107 lines
3.1 KiB
Go
package protocol
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import (
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"bytes"
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"fmt"
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"io/ioutil"
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"net/http"
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neturl "net/url"
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"github.com/keighl/metabolize"
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"go.uber.org/zap"
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"github.com/status-im/status-go/images"
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"github.com/status-im/status-go/protocol/common"
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"github.com/status-im/status-go/protocol/protobuf"
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)
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type OpenGraphMetadata struct {
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Title string `json:"title" meta:"og:title"`
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Description string `json:"description" meta:"og:description"`
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ThumbnailURL string `json:"thumbnailUrl" meta:"og:image"`
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}
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// OpenGraphUnfurler should be preferred over OEmbedUnfurler because oEmbed
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// gives back a JSON response with a "html" field that's supposed to be embedded
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// in an iframe (hardly useful for existing Status' clients).
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type OpenGraphUnfurler struct {
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url *neturl.URL
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logger *zap.Logger
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httpClient *http.Client
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}
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func NewOpenGraphUnfurler(URL *neturl.URL, logger *zap.Logger, httpClient *http.Client) *OpenGraphUnfurler {
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return &OpenGraphUnfurler{
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url: URL,
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logger: logger,
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httpClient: httpClient,
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}
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}
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func (u *OpenGraphUnfurler) Unfurl() (*common.LinkPreview, error) {
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preview := newDefaultLinkPreview(u.url)
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preview.Type = protobuf.UnfurledLink_LINK
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headers := map[string]string{
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"accept": headerAcceptText,
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"accept-language": headerAcceptLanguage,
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"user-agent": headerUserAgent,
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}
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bodyBytes, err := fetchBody(u.logger, u.httpClient, u.url.String(), headers)
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if err != nil {
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return preview, err
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}
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var ogMetadata OpenGraphMetadata
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err = metabolize.Metabolize(ioutil.NopCloser(bytes.NewBuffer(bodyBytes)), &ogMetadata)
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if err != nil {
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return preview, fmt.Errorf("failed to parse OpenGraph data")
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}
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// There are URLs like https://wikipedia.org/ that don't have an OpenGraph
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// title tag, but article pages do. In the future, we can fallback to the
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// website's title by using the <title> tag.
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if ogMetadata.Title == "" {
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return preview, fmt.Errorf("missing required title in OpenGraph response")
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}
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if ogMetadata.ThumbnailURL != "" {
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t, err := fetchThumbnail(u.logger, u.httpClient, ogMetadata.ThumbnailURL)
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if err != nil {
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// Given we want to fetch thumbnails on a best-effort basis, if an error
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// happens we simply log it.
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u.logger.Info("failed to fetch thumbnail", zap.String("url", u.url.String()), zap.Error(err))
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} else {
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preview.Thumbnail = t
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}
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}
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preview.Title = ogMetadata.Title
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preview.Description = ogMetadata.Description
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return preview, nil
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}
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func fetchThumbnail(logger *zap.Logger, httpClient *http.Client, url string) (common.LinkPreviewThumbnail, error) {
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var thumbnail common.LinkPreviewThumbnail
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imgBytes, err := fetchBody(logger, httpClient, url, nil)
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if err != nil {
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return thumbnail, fmt.Errorf("could not fetch thumbnail url='%s': %w", url, err)
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}
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width, height, err := images.GetImageDimensions(imgBytes)
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if err != nil {
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return thumbnail, fmt.Errorf("could not get image dimensions url='%s': %w", url, err)
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}
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thumbnail.Width = width
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thumbnail.Height = height
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dataURI, err := images.GetPayloadDataURI(imgBytes)
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if err != nil {
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return thumbnail, fmt.Errorf("could not build data URI url='%s': %w", url, err)
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}
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thumbnail.DataURI = dataURI
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return thumbnail, nil
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}
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