Add support for the jukebox endpoint

This supports most of jukeboxControl.view as far as i can tell. Things
seem to be playing ok without freaking out

I've also only tested it a little bit with ultrasonic but it does
appear to be working pretty well

server/ctrlsubsonic/handlers_common.go

@@ -112,6 +112,7 @@ func (c *Controller) ServeGetUser(r *http.Request) *spec.Response {
 	sub.User = &spec.User{
 		Username:          user.Name,
 		AdminRole:         user.IsAdmin,
+		JukeboxRole:       true,
 		ScrobblingEnabled: user.LastFMSession != "",
 		Folder:            []int{1},
 	}
@@ -313,3 +314,51 @@ func (c *Controller) ServeGetRandomSongs(r *http.Request) *spec.Response {
 	}
 	return sub
 }
+
+func (c *Controller) ServeJukebox(r *http.Request) *spec.Response {
+	params := r.Context().Value(CtxParams).(params.Params)
+	switch params.Get("action") {
+	case "set":
+		var tracks []*db.Track
+		ids := params.GetFirstListInt("id")
+		if len(ids) == 0 {
+			c.Jukebox.ClearTracks()
+		}
+		for _, id := range ids {
+			track := &db.Track{}
+			err := c.DB.Preload("Album").First(track, id).Error
+			if err != nil {
+				return spec.NewError(10, "couldn't find tracks with provided ids")
+			}
+			tracks = append(tracks, track)
+		}
+		c.Jukebox.SetTracks(tracks)
+	case "clear":
+		c.Jukebox.ClearTracks()
+	case "remove":
+		index, err := params.GetInt("index")
+		if err != nil {
+			return spec.NewError(10, "please provide an id for remove actions")
+		}
+		c.Jukebox.RemoveTrack(index)
+	case "stop":
+		c.Jukebox.Stop()
+	case "start":
+		c.Jukebox.Start()
+	case "skip":
+		index, err := params.GetInt("index")
+		var skipCurrent bool
+		if err != nil {
+			skipCurrent = true
+		}
+		c.Jukebox.Skip(index, skipCurrent)
+	case "get":
+		sub := spec.NewResponse()
+		sub.JukeboxPlaylist = c.Jukebox.GetTracks()
+		return sub
+	}
+	// All actions except get are expected to return a status
+	sub := spec.NewResponse()
+	sub.JukeboxStatus = c.Jukebox.Status()
+	return sub
+}

server/ctrlsubsonic/spec/spec.go

@@ -41,6 +41,8 @@ type Response struct {
 	ArtistInfoTwo     *ArtistInfo        `xml:"artistInfo2"       json:"artistInfo2,omitempty"`
 	Genres            *Genres            `xml:"genres"            json:"genres,omitempty"`
 	PlayQueue         *PlayQueue         `xml:"playQueue"         json:"playQueue,omitempty"`
+	JukeboxStatus     *JukeboxStatus     `xml:"jukeboxStatus"     json:"jukeboxStatus,omitempty"`
+	JukeboxPlaylist   *JukeboxPlaylist   `xml:"jukeboxPlaylist"   json:"jukeboxPlaylist,omitempty"`
 }
 
 func NewResponse() *Response {
@@ -269,3 +271,15 @@ type PlayQueue struct {
 	ChangedBy string        `xml:"changedBy,attr"          json:"changedBy"`
 	List      []*TrackChild `xml:"entry,omitempty"         json:"entry,omitempty"`
 }
+
+type JukeboxStatus struct {
+	CurrentIndex int     `xml:"currentIndex,attr" json:"currentIndex"`
+	Playing      bool    `xml:"playing,attr"      json:"playing"`
+	Gain         float64 `xml:"gain,attr"         json:"gain"`
+	Position     int     `xml:"position,attr"     json:"position"`
+}
+
+type JukeboxPlaylist struct {
+	List []*TrackChild `xml:"entry,omitempty" json:"entry,omitempty"`
+	JukeboxStatus
+}