feat: add twitch live detection to streamer list

internal/twitch/service.go

@@ -33,6 +33,17 @@ type Channel struct {
 	Login string
 }
 
+// StreamInfo describes whether a channel is live.
+type StreamInfo struct {
+	Online bool
+}
+
+// PlaybackToken carries the Twitch playback token/signature pair for live HLS access.
+type PlaybackToken struct {
+	Signature string
+	Value     string
+}
+
 // StreamerStatus describes one row's resolution state in the UI.
 type StreamerStatus string
 
@@ -47,6 +58,7 @@ type StreamerEntry struct {
 	ConfigLogin string
 	Login       string
 	ChannelID   string
+	Live        bool
 	Status      StreamerStatus
 	Error       string
 }
@@ -106,3 +118,44 @@ func (s *Service) ResolveStreamer(ctx context.Context, login string) (*Channel,
 	}
 	return &Channel{ID: data.User.ID, Login: resolvedLogin}, nil
 }
+
+// StreamInfo resolves whether the given channel ID is currently live.
+func (s *Service) StreamInfo(ctx context.Context, channelID string) (*StreamInfo, error) {
+	var data struct {
+		User *struct {
+			Stream *struct {
+				ID string `json:"id"`
+			} `json:"stream"`
+		} `json:"user"`
+	}
+	if err := s.GQL.Do(ctx, gql.WithIsStreamLiveQuery(channelID), &data); err != nil {
+		return nil, err
+	}
+	if data.User == nil {
+		return nil, fmt.Errorf("stream info missing user for channel %s", channelID)
+	}
+	if data.User.Stream == nil {
+		return &StreamInfo{Online: false}, nil
+	}
+	return &StreamInfo{Online: true}, nil
+}
+
+// PlaybackAccessToken fetches the Twitch playback token needed to access a live stream.
+func (s *Service) PlaybackAccessToken(ctx context.Context, login string) (*PlaybackToken, error) {
+	var data struct {
+		StreamPlaybackAccessToken *struct {
+			Signature string `json:"signature"`
+			Value     string `json:"value"`
+		} `json:"streamPlaybackAccessToken"`
+	}
+	if err := s.GQL.Do(ctx, gql.PlaybackAccessToken(login), &data); err != nil {
+		return nil, err
+	}
+	if data.StreamPlaybackAccessToken == nil || data.StreamPlaybackAccessToken.Signature == "" || data.StreamPlaybackAccessToken.Value == "" {
+		return nil, fmt.Errorf("playback access token missing signature or value for %s", login)
+	}
+	return &PlaybackToken{
+		Signature: data.StreamPlaybackAccessToken.Signature,
+		Value:     data.StreamPlaybackAccessToken.Value,
+	}, nil
+}

internal/twitch/service_test.go

@@ -63,3 +63,64 @@ func TestResolveStreamerNotFound(t *testing.T) {
 		t.Fatalf("error = %v", err)
 	}
 }
+
+func TestStreamInfoOffline(t *testing.T) {
+	t.Parallel()
+
+	client := &fakeGQL{data: map[string]string{
+		"WithIsStreamLiveQuery": `{"user":{"stream":null}}`,
+	}}
+	service := &Service{GQL: client}
+	info, err := service.StreamInfo(context.Background(), "123")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if info.Online {
+		t.Fatalf("info = %#v, want offline", info)
+	}
+}
+
+func TestStreamInfoOnline(t *testing.T) {
+	t.Parallel()
+
+	client := &fakeGQL{data: map[string]string{
+		"WithIsStreamLiveQuery": `{"user":{"stream":{"id":"broadcast"}}}`,
+	}}
+	service := &Service{GQL: client}
+	info, err := service.StreamInfo(context.Background(), "123")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !info.Online {
+		t.Fatalf("info = %#v, want online", info)
+	}
+}
+
+func TestPlaybackAccessToken(t *testing.T) {
+	t.Parallel()
+
+	client := &fakeGQL{data: map[string]string{
+		"PlaybackAccessToken": `{"streamPlaybackAccessToken":{"signature":"sig","value":"token"}}`,
+	}}
+	service := &Service{GQL: client}
+	token, err := service.PlaybackAccessToken(context.Background(), "streamer")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if token.Signature != "sig" || token.Value != "token" {
+		t.Fatalf("token = %#v", token)
+	}
+}
+
+func TestPlaybackAccessTokenMissingFields(t *testing.T) {
+	t.Parallel()
+
+	client := &fakeGQL{data: map[string]string{
+		"PlaybackAccessToken": `{"streamPlaybackAccessToken":{"signature":"sig"}}`,
+	}}
+	service := &Service{GQL: client}
+	_, err := service.PlaybackAccessToken(context.Background(), "streamer")
+	if err == nil {
+		t.Fatal("expected error")
+	}
+}