status-go/protocol/urls/urls.go

296 lines
7.5 KiB
Go

package urls
import (
"encoding/json"
"fmt"
"html"
"io/ioutil"
"net/http"
"net/url"
"strings"
"time"
"github.com/keighl/metabolize"
)
type YoutubeOembedData struct {
ProviderName string `json:"provider_name"`
Title string `json:"title"`
ThumbnailURL string `json:"thumbnail_url"`
}
type TwitterOembedData struct {
ProviderName string `json:"provider_name"`
AuthorName string `json:"author_name"`
HTML string `json:"html"`
}
type GiphyOembedData struct {
ProviderName string `json:"provider_name"`
Title string `json:"title"`
URL string `json:"url"`
Height int `json:"height"`
Width int `json:"width"`
}
type LinkPreviewData struct {
Site string `json:"site" meta:"og:site_name"`
Title string `json:"title" meta:"og:title"`
ThumbnailURL string `json:"thumbnailUrl" meta:"og:image"`
ContentType string `json:"contentType"`
Height int `json:"height"`
Width int `json:"width"`
}
type Site struct {
Title string `json:"title"`
Address string `json:"address"`
ImageSite bool `json:"imageSite"`
}
const (
YoutubeOembedLink = "https://www.youtube.com/oembed?format=json&url=%s"
TwitterOembedLink = "https://publish.twitter.com/oembed?url=%s"
GiphyOembedLink = "https://giphy.com/services/oembed?url=%s"
)
var (
httpClient = http.Client{Timeout: 30 * time.Second}
)
func LinkPreviewWhitelist() []Site {
return []Site{
{
Title: "Status",
Address: "our.status.im",
ImageSite: false,
},
{
Title: "YouTube",
Address: "youtube.com",
ImageSite: false,
},
{
Title: "YouTube with subdomain",
Address: "www.youtube.com",
ImageSite: false,
},
{
Title: "YouTube shortener",
Address: "youtu.be",
ImageSite: false,
},
{
Title: "YouTube Mobile",
Address: "m.youtube.com",
ImageSite: false,
},
{
Title: "Twitter",
Address: "twitter.com",
ImageSite: false,
},
{
Title: "Twitter Mobile",
Address: "mobile.twitter.com",
ImageSite: false,
},
{
Title: "GIPHY GIFs shortener",
Address: "gph.is",
ImageSite: true,
},
{
Title: "GIPHY GIFs",
Address: "giphy.com",
ImageSite: true,
},
{
Title: "GIPHY GIFs subdomain",
Address: "media.giphy.com",
ImageSite: true,
},
{
Title: "GitHub",
Address: "github.com",
ImageSite: false,
},
{
Title: "Tenor GIFs subdomain",
Address: "media.tenor.com",
ImageSite: false,
},
// Medium unfurling is failing - https://github.com/status-im/status-go/issues/2192
//
// {
// Title: "Medium",
// Address: "medium.com",
// ImageSite: false,
// },
}
}
func getURLContent(url string) (data []byte, err error) {
response, err := httpClient.Get(url)
if err != nil {
return data, fmt.Errorf("can't get content from link %s", url)
}
defer response.Body.Close()
return ioutil.ReadAll(response.Body)
}
func GetOembed(name, endpoint, url string, data interface{}) error {
oembedLink := fmt.Sprintf(endpoint, url)
jsonBytes, err := getURLContent(oembedLink)
if err != nil {
return fmt.Errorf("can't get bytes from %s oembed response on %s link", name, oembedLink)
}
return json.Unmarshal(jsonBytes, &data)
}
func GetYoutubePreviewData(link string) (previewData LinkPreviewData, err error) {
oembedData := new(YoutubeOembedData)
err = GetOembed("Youtube", YoutubeOembedLink, link, &oembedData)
if err != nil {
return
}
previewData.Title = oembedData.Title
previewData.Site = oembedData.ProviderName
previewData.ThumbnailURL = oembedData.ThumbnailURL
return
}
func GetTwitterPreviewData(link string) (previewData LinkPreviewData, err error) {
oembedData := new(TwitterOembedData)
err = GetOembed("Twitter", TwitterOembedLink, link, oembedData)
if err != nil {
return previewData, err
}
previewData.Title = getReadableTextFromTweetHTML(oembedData.HTML)
previewData.Site = oembedData.ProviderName
return previewData, nil
}
func getReadableTextFromTweetHTML(s string) string {
s = strings.ReplaceAll(s, "\u003Cbr\u003E", "\n") // Adds line break for all <br>
s = strings.ReplaceAll(s, "https://", "\nhttps://") // Displays links in next line
s = html.UnescapeString(s) // Parses html special characters like &#225;
s = stripHTMLTags(s)
s = strings.TrimSpace(s)
s = strings.TrimRight(s, "\n")
s = strings.TrimLeft(s, "\n")
return s
}
func GetGenericLinkPreviewData(link string) (previewData LinkPreviewData, err error) {
res, err := httpClient.Get(link)
if err != nil {
return previewData, fmt.Errorf("can't get content from link %s", link)
}
err = metabolize.Metabolize(res.Body, &previewData)
if err != nil {
return previewData, fmt.Errorf("can't get meta info from link %s", link)
}
return previewData, nil
}
func FakeGenericImageLinkPreviewData(title string, link string) (previewData LinkPreviewData, err error) {
url, err := url.Parse(link)
if err != nil {
return previewData, fmt.Errorf("Failed to parse link %s", link)
}
res, err := httpClient.Head(link)
if err != nil {
return previewData, fmt.Errorf("Failed to get HEAD from link %s", link)
}
if res.StatusCode != 200 {
return previewData, fmt.Errorf("Image link %s is not available", link)
}
previewData.Title = title
previewData.Site = strings.ToLower(url.Hostname())
previewData.ContentType = res.Header.Get("Content-type")
previewData.ThumbnailURL = link
previewData.Height = 0
previewData.Width = 0
return previewData, nil
}
func GetGiphyPreviewData(link string) (previewData LinkPreviewData, err error) {
oembedData := new(GiphyOembedData)
err = GetOembed("Giphy", GiphyOembedLink, link, oembedData)
if err != nil {
return previewData, err
}
previewData.Title = oembedData.Title
previewData.Site = oembedData.ProviderName
previewData.ThumbnailURL = oembedData.URL
previewData.Height = oembedData.Height
previewData.Width = oembedData.Width
return previewData, nil
}
// GetGiphyLongURL Giphy has a shortener service called gph.is, the oembed service doesn't work with shortened urls,
// so we need to fetch the long url first
func GetGiphyLongURL(shortURL string) (longURL string, err error) {
res, err := httpClient.Get(shortURL)
if err != nil {
return longURL, fmt.Errorf("can't get bytes from Giphy's short url at %s", shortURL)
}
canonicalURL := res.Request.URL.String()
if canonicalURL == shortURL {
// no redirect, ie. not a valid url
return longURL, fmt.Errorf("unable to process Giphy's short url at %s", shortURL)
}
return canonicalURL, err
}
func GetGiphyShortURLPreviewData(shortURL string) (data LinkPreviewData, err error) {
longURL, err := GetGiphyLongURL(shortURL)
if err != nil {
return data, err
}
return GetGiphyPreviewData(longURL)
}
func GetLinkPreviewData(link string) (previewData LinkPreviewData, err error) {
u, err := url.Parse(link)
if err != nil {
return previewData, fmt.Errorf("cant't parse link %s", link)
}
hostname := strings.ToLower(u.Hostname())
switch hostname {
case "youtube.com", "youtu.be", "www.youtube.com", "m.youtube.com":
return GetYoutubePreviewData(link)
case "github.com", "our.status.im":
return GetGenericLinkPreviewData(link)
case "giphy.com", "media.giphy.com":
return GetGiphyPreviewData(link)
case "gph.is":
return GetGiphyShortURLPreviewData(link)
case "twitter.com", "mobile.twitter.com":
return GetTwitterPreviewData(link)
case "media.tenor.com":
return FakeGenericImageLinkPreviewData("Tenor", link)
default:
return previewData, fmt.Errorf("link %s isn't whitelisted. Hostname - %s", link, u.Hostname())
}
}