more progress on radios

backend/mediaprovider/subsonic/subsonicmediaprovider.go

@@ -424,6 +424,7 @@ func (s *subsonicMediaProvider) GetRadioStations() ([]*mediaprovider.RadioStatio
 	}
 	return sharedutil.MapSlice(rs, func(rs *subsonic.InternetRadioStation) *mediaprovider.RadioStation {
 		return &mediaprovider.RadioStation{
+			// TODO - subsonic library is missing ID in its radiostation object. add it
 			ID:          "radio-" + strings.ReplaceAll(rs.Name, " ", ""),
 			Name:        rs.Name,
 			HomePageURL: rs.HomePageUrl,

backend/playbackengine.go

@@ -235,6 +235,31 @@ func (p *playbackEngine) LoadTracks(tracks []*mediaprovider.Track, insertQueueMo
 	return nil
 }
 
+func (p *playbackEngine) LoadRadioStation(radio *mediaprovider.RadioStation, insertMode InsertQueueMode) {
+	if insertMode == Replace {
+		p.player.Stop()
+		p.nowPlayingIdx = -1
+		p.playQueue = nil
+	}
+	needToSetNext := insertMode == InsertNext || (insertMode == Append && p.nowPlayingIdx == len(p.playQueue)-1)
+	insertIdx := len(p.playQueue)
+	if insertMode == InsertNext {
+		insertIdx = p.nowPlayingIdx + 1
+	}
+	new := make([]mediaprovider.MediaItem, len(p.playQueue)+1)
+	firstHalf := p.playQueue[:insertIdx]
+	copy(new, firstHalf)
+	new[len(firstHalf)] = radio
+	copy(new[len(firstHalf)+1:], p.playQueue[insertIdx:])
+	p.playQueue = new
+
+	if needToSetNext {
+		p.setNextTrack(p.nowPlayingIdx + 1)
+	}
+
+	p.invokeNoArgCallbacks(p.onQueueChange)
+}
+
 // Stop playback and clear the play queue.
 func (p *playbackEngine) StopAndClearPlayQueue() {
 	changed := len(p.playQueue) > 0

backend/playbackmanager.go

@@ -182,6 +182,10 @@ func (p *PlaybackManager) PlaySimilarSongs(id string) {
 	})
 }
 
+func (p *PlaybackManager) LoadRadioStation(station *mediaprovider.RadioStation, queueMode InsertQueueMode) {
+	p.engine.LoadRadioStation(station, queueMode)
+}
+
 func (p *PlaybackManager) fetchAndPlayTracks(fetchFn func() ([]*mediaprovider.Track, error)) {
 	if songs, err := fetchFn(); err != nil {
 		log.Printf("error fetching tracks: %s", err.Error())