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linkpreview_unfurler.go
80 lines (63 loc) · 1.99 KB
/
linkpreview_unfurler.go
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package protocol
import (
"context"
"fmt"
"io/ioutil"
"net/http"
neturl "net/url"
"time"
"go.uber.org/zap"
"github.com/status-im/status-go/protocol/common"
)
const (
DefaultRequestTimeout = 15000 * time.Millisecond
headerAcceptJSON = "application/json; charset=utf-8"
headerAcceptText = "text/html; charset=utf-8"
// Without a particular user agent, many providers treat status-go as a
// gluttony bot, and either respond more frequently with a 429 (Too Many
// Requests), or simply refuse to return valid data. Note that using a known
// browser UA doesn't work well with some providers, such as Spotify,
// apparently they still flag status-go as a bad actor.
headerUserAgent = "status-go/v0.151.15"
// Currently set to English, but we could make this setting dynamic according
// to the user's language of choice.
headerAcceptLanguage = "en-US,en;q=0.5"
)
type Headers map[string]string
type Unfurler interface {
Unfurl() (*common.LinkPreview, error)
}
func newDefaultLinkPreview(url *neturl.URL) *common.LinkPreview {
return &common.LinkPreview{
URL: url.String(),
Hostname: url.Hostname(),
}
}
func fetchBody(logger *zap.Logger, httpClient *http.Client, url string, headers Headers) ([]byte, error) {
ctx, cancel := context.WithTimeout(context.Background(), DefaultRequestTimeout)
defer cancel()
req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
if err != nil {
return nil, fmt.Errorf("failed to perform HTTP request: %w", err)
}
for k, v := range headers {
req.Header.Set(k, v)
}
res, err := httpClient.Do(req)
if err != nil {
return nil, err
}
defer func() {
if err := res.Body.Close(); err != nil {
logger.Error("failed to close response body", zap.Error(err))
}
}()
if res.StatusCode >= http.StatusBadRequest {
return nil, fmt.Errorf("http request failed, statusCode='%d'", res.StatusCode)
}
bodyBytes, err := ioutil.ReadAll(res.Body)
if err != nil {
return nil, fmt.Errorf("failed to read body bytes: %w", err)
}
return bodyBytes, nil
}