status-go/protocol/linkpreview_unfurler_oembed.go

94 lines
2.1 KiB
Go

package protocol
import (
"encoding/json"
"fmt"
"net/http"
neturl "net/url"
"go.uber.org/zap"
"github.com/status-im/status-go/protocol/common"
"github.com/status-im/status-go/protocol/protobuf"
)
type OEmbedUnfurler struct {
logger *zap.Logger
httpClient *http.Client
// oembedEndpoint describes where the consumer may request representations for
// the supported URL scheme. For example, for YouTube, it is
// https://www.youtube.com/oembed.
oembedEndpoint string
// url is the actual URL to be unfurled.
url *neturl.URL
}
func NewOEmbedUnfurler(oembedEndpoint string,
url *neturl.URL,
logger *zap.Logger,
httpClient *http.Client) *OEmbedUnfurler {
return &OEmbedUnfurler{
oembedEndpoint: oembedEndpoint,
url: url,
logger: logger,
httpClient: httpClient,
}
}
type OEmbedResponse struct {
Title string `json:"title"`
ThumbnailURL string `json:"thumbnail_url"`
}
func (u *OEmbedUnfurler) newOEmbedURL() (*neturl.URL, error) {
oembedURL, err := neturl.Parse(u.oembedEndpoint)
if err != nil {
return nil, err
}
// When format is specified, the provider MUST return data in the requested
// format, else return an error.
oembedURL.RawQuery = neturl.Values{
"url": {u.url.String()},
"format": {"json"},
}.Encode()
return oembedURL, nil
}
func (u OEmbedUnfurler) Unfurl() (*common.LinkPreview, error) {
preview := newDefaultLinkPreview(u.url)
preview.Type = protobuf.UnfurledLink_LINK
oembedURL, err := u.newOEmbedURL()
if err != nil {
return preview, err
}
headers := map[string]string{
"accept": headerAcceptJSON,
"accept-language": headerAcceptLanguage,
"user-agent": headerUserAgent,
}
oembedBytes, err := fetchBody(u.logger, u.httpClient, oembedURL.String(), headers)
if err != nil {
return preview, err
}
var oembedResponse OEmbedResponse
if err != nil {
return preview, err
}
err = json.Unmarshal(oembedBytes, &oembedResponse)
if err != nil {
return preview, err
}
if oembedResponse.Title == "" {
return preview, fmt.Errorf("missing required title in oEmbed response")
}
preview.Title = oembedResponse.Title
return preview, nil
}