package main import ( "context" "encoding/json" "io" "io/ioutil" "net/http" "net/url" "strings" "time" "github.com/Luzifer/go_helpers/v2/backoff" "github.com/pkg/errors" ) const ( twitchAPIRequestLimit = 5 twitchAPIRequestTimeout = 2 * time.Second ) type ( twitchAdapter struct { clientID string clientSecret string token string } twitchStreamListing struct { Data []struct { ID string `json:"id"` UserID string `json:"user_id"` UserLogin string `json:"user_login"` UserName string `json:"user_name"` GameID string `json:"game_id"` GameName string `json:"game_name"` Type string `json:"type"` Title string `json:"title"` ViewerCount int64 `json:"viewer_count"` StartedAt time.Time `json:"started_at"` Language string `json:"language"` ThumbnailURL string `json:"thumbnail_url"` TagIds []string `json:"tag_ids"` IsMature bool `json:"is_mature"` } `json:"data"` Pagination struct { Cursor string `json:"cursor"` } `json:"pagination"` } twitchStreamSchedule struct { Data struct { Segments []struct { ID string `json:"id"` StartTime *time.Time `json:"start_time"` EndTime *time.Time `json:"end_time"` Title string `json:"title"` CanceledUntil *time.Time `json:"canceled_until"` Category *struct { ID string `json:"id"` Name string `json:"name"` } `json:"category"` IsRecurring bool `json:"is_recurring"` } `json:"segments"` BroadcasterID string `json:"broadcaster_id"` BroadcasterName string `json:"broadcaster_name"` BroadcasterLogin string `json:"broadcaster_login"` Vacation *struct { StartTime *time.Time `json:"start_time"` EndTime *time.Time `json:"end_time"` } `json:"vacation"` } `json:"data"` Pagination struct { Cursor string `json:"cursor"` } `json:"pagination"` } twitchUserListing struct { Data []struct { ID string `json:"id"` Login string `json:"login"` DisplayName string `json:"display_name"` Type string `json:"type"` BroadcasterType string `json:"broadcaster_type"` Description string `json:"description"` ProfileImageURL string `json:"profile_image_url"` OfflineImageURL string `json:"offline_image_url"` ViewCount int64 `json:"view_count"` Email string `json:"email"` CreatedAt time.Time `json:"created_at"` } `json:"data"` } ) func newTwitchAdapter(clientID, clientSecret, token string) *twitchAdapter { return &twitchAdapter{ clientID: clientID, clientSecret: clientSecret, token: token, } } func (t twitchAdapter) GetChannelStreamSchedule(ctx context.Context, broadcasterID string, startTime *time.Time) (*twitchStreamSchedule, error) { out := &twitchStreamSchedule{} params := make(url.Values) params.Set("broadcaster_id", broadcasterID) if startTime != nil { params.Set("start_time", startTime.Format(time.RFC3339)) } return out, backoff.NewBackoff(). WithMaxIterations(twitchAPIRequestLimit). Retry(func() error { return errors.Wrap( t.request(ctx, http.MethodGet, "/helix/schedule", params, nil, out), "fetching schedule", ) }) } func (t twitchAdapter) GetStreamsForUser(ctx context.Context, userNames ...string) (*twitchStreamListing, error) { out := &twitchStreamListing{} params := make(url.Values) params.Set("first", "100") params["user_login"] = userNames return out, backoff.NewBackoff(). WithMaxIterations(twitchAPIRequestLimit). Retry(func() error { return errors.Wrap( t.request(ctx, http.MethodGet, "/helix/streams", params, nil, out), "fetching streams", ) }) } func (t twitchAdapter) GetUserByUsername(ctx context.Context, userNames ...string) (*twitchUserListing, error) { out := &twitchUserListing{} params := make(url.Values) params.Set("first", "100") params["login"] = userNames return out, backoff.NewBackoff(). WithMaxIterations(twitchAPIRequestLimit). Retry(func() error { return errors.Wrap( t.request(ctx, http.MethodGet, "/helix/users", params, nil, out), "fetching user", ) }) } func (t twitchAdapter) getAppAccessToken(ctx context.Context) (string, error) { var rData struct { AccessToken string `json:"access_token"` RefreshToken string `json:"refresh_token"` ExpiresIn int `json:"expires_in"` Scope []interface{} `json:"scope"` TokenType string `json:"token_type"` } params := make(url.Values) params.Set("client_id", t.clientID) params.Set("client_secret", t.clientSecret) params.Set("grant_type", "client_credentials") u, _ := url.Parse("https://id.twitch.tv/oauth2/token") u.RawQuery = params.Encode() req, _ := http.NewRequestWithContext(ctx, http.MethodPost, u.String(), nil) resp, err := http.DefaultClient.Do(req) if err != nil { return "", errors.Wrap(err, "fetching response") } defer resp.Body.Close() if resp.StatusCode != http.StatusOK { body, err := ioutil.ReadAll(resp.Body) if err != nil { return "", errors.Wrapf(err, "unexpected status %d and cannot read body", resp.StatusCode) } return "", errors.Errorf("unexpected status %d: %s", resp.StatusCode, body) } return rData.AccessToken, errors.Wrap( json.NewDecoder(resp.Body).Decode(&rData), "decoding response", ) } func (t twitchAdapter) request(ctx context.Context, method, path string, params url.Values, body io.Reader, output interface{}) error { ctxTimed, cancel := context.WithTimeout(ctx, twitchAPIRequestTimeout) defer cancel() u, _ := url.Parse(strings.Join([]string{ "https://api.twitch.tv", strings.TrimLeft(path, "/"), }, "/")) if params != nil { u.RawQuery = params.Encode() } req, _ := http.NewRequestWithContext(ctxTimed, method, u.String(), body) req.Header.Set("Authorization", strings.Join([]string{"Bearer", t.token}, " ")) req.Header.Set("Client-Id", t.clientID) if t.token == "" { accessToken, err := t.getAppAccessToken(ctx) if err != nil { return errors.Wrap(err, "fetching app-access-token") } req.Header.Set("Authorization", strings.Join([]string{"Bearer", accessToken}, " ")) } resp, err := http.DefaultClient.Do(req) if err != nil { return errors.Wrap(err, "fetching response") } defer resp.Body.Close() if resp.StatusCode != http.StatusOK { body, err := ioutil.ReadAll(resp.Body) if err != nil { return errors.Wrapf(err, "unexpected status %d and cannot read body", resp.StatusCode) } return errors.Errorf("unexpected status %d: %s", resp.StatusCode, body) } if output == nil { return nil } return errors.Wrap( json.NewDecoder(resp.Body).Decode(output), "decoding response", ) }