feat(subsonic): implement getSimilarSongs2.view

closes #195

server/ctrlsubsonic/handlers_by_tags.go

@@ -512,3 +512,64 @@ func (c *Controller) ServeGetSimilarSongs(r *http.Request) *spec.Response {
 	}
 	return sub
 }
+
+func (c *Controller) ServeGetSimilarSongsTwo(r *http.Request) *spec.Response {
+	params := r.Context().Value(CtxParams).(params.Params)
+	count := params.GetOrInt("count", 10)
+	id, err := params.GetID("id")
+	if err != nil || id.Type != specid.Artist {
+		return spec.NewError(10, "please provide an artist `id` parameter")
+	}
+
+	apiKey, _ := c.DB.GetSetting("lastfm_api_key")
+	if apiKey == "" {
+		return spec.NewResponse()
+	}
+
+	var artist db.Artist
+	err = c.DB.
+		Where("id=?", id.Value).
+		First(&artist).
+		Error
+	if errors.Is(err, gorm.ErrRecordNotFound) {
+		return spec.NewError(0, "artist with id `%s` not found", id)
+	}
+
+	similarArtists, err := lastfm.ArtistGetSimilar(apiKey, artist.Name)
+	if err != nil {
+		return spec.NewError(0, "fetching artist similar artists: %v", err)
+	}
+	if len(similarArtists.Artists) == 0 {
+		return spec.NewError(0, "no similar artist found for: %v", artist.Name)
+	}
+
+	artistNames := make([]string, len(similarArtists.Artists))
+	for i, similarArtist := range similarArtists.Artists {
+		artistNames[i] = similarArtist.Name
+	}
+
+	var tracks []*db.Track
+	err = c.DB.
+		Preload("Album").
+		Joins("JOIN artists on tracks.artist_id=artists.id").
+		Where("artists.name IN (?)", artistNames).
+		Order(gorm.Expr("random()")).
+		Limit(count).
+		Find(&tracks).
+		Error
+	if err != nil {
+		return spec.NewError(0, "error finding tracks: %v", err)
+	}
+	if len(tracks) == 0 {
+		return spec.NewError(70, "no similar song could be match with collection in database: %v", artist.Name)
+	}
+
+	sub := spec.NewResponse()
+	sub.SimilarSongsTwo = &spec.SimilarSongsTwo{
+		Tracks: make([]*spec.TrackChild, len(tracks)),
+	}
+	for i, track := range tracks {
+		sub.SimilarSongsTwo.Tracks[i] = spec.NewTrackByTags(track, track.Album)
+	}
+	return sub
+}

server/ctrlsubsonic/spec/spec.go

@@ -49,6 +49,7 @@ type Response struct {
 	StarredTwo        *StarredTwo        `xml:"starred2"          json:"starred2,omitempty"`
 	TopSongs          *TopSongs          `xml:"topSongs"          json:"topSongs,omitempty"`
 	SimilarSongs      *SimilarSongs      `xml:"similarSongs"      json:"similarSongs,omitempty"`
+	SimilarSongsTwo   *SimilarSongsTwo   `xml:"similarSongs2"     json:"similarSongs2,omitempty"`
 }
 
 func NewResponse() *Response {
@@ -362,3 +363,7 @@ type TopSongs struct {
 type SimilarSongs struct {
 	Tracks []*TrackChild `xml:"song,omitempty" json:"song,omitempty"`
 }
+
+type SimilarSongsTwo struct {
+	Tracks []*TrackChild `xml:"song,omitempty" json:"song,omitempty"`
+}

server/scrobble/lastfm/lastfm.go

@@ -32,6 +32,7 @@ type LastFM struct {
 	Artist         Artist         `xml:"artist"`
 	TopTracks      TopTracks      `xml:"toptracks"`
 	SimilarTracks  SimilarTracks  `xml:"similartracks"`
+	SimilarArtists SimilarArtists `xml:"similarartists"`
 }
 
 type Session struct {
@@ -45,6 +46,18 @@ type Error struct {
 	Value string `xml:",chardata"`
 }
 
+type SimilarArtist struct {
+	XMLName xml.Name `xml:"artist"`
+	Name    string   `xml:"name"`
+	MBID    string   `xml:"mbid"`
+	URL     string   `xml:"url"`
+	Image   []struct {
+		Text string `xml:",chardata"`
+		Size string `xml:"size,attr"`
+	} `xml:"image"`
+	Streamable string `xml:"streamable"`
+}
+
 type Artist struct {
 	XMLName xml.Name `xml:"artist"`
 	Name    string   `xml:"name"`
@@ -92,6 +105,12 @@ type SimilarTracks struct {
 	Tracks  []Track  `xml:"track"`
 }
 
+type SimilarArtists struct {
+	XMLName xml.Name `xml:"similarartists"`
+	Artist  string   `xml:"artist,attr"`
+	Artists []Artist `xml:"artist"`
+}
+
 type Track struct {
 	Rank      int     `xml:"rank,attr"`
 	Tracks    []Track `xml:"track"`
@@ -178,6 +197,19 @@ func TrackGetSimilarTracks(apiKey string, artistName, trackName string) (Similar
 	}
 	return resp.SimilarTracks, nil
 }
+
+func ArtistGetSimilar(apiKey string, artistName string) (SimilarArtists, error) {
+	params := url.Values{}
+	params.Add("method", "artist.getSimilar")
+	params.Add("api_key", apiKey)
+	params.Add("artist", artistName)
+	resp, err := makeRequest("GET", params)
+	if err != nil {
+		return SimilarArtists{}, fmt.Errorf("making similar artists GET:  %w", err)
+	}
+	return resp.SimilarArtists, nil
+}
+
 func GetSession(apiKey, secret, token string) (string, error) {
 	params := url.Values{}
 	params.Add("method", "auth.getSession")

server/server.go

@@ -219,6 +219,7 @@ func setupSubsonic(r *mux.Router, ctrl *ctrlsubsonic.Controller) {
 	r.Handle("/deleteBookmark{_:(?:\\.view)?}", ctrl.H(ctrl.ServeDeleteBookmark))
 	r.Handle("/getTopSongs{_:(?:\\.view)?}", ctrl.H(ctrl.ServeGetTopSongs))
 	r.Handle("/getSimilarSongs{_:(?:\\.view)?}", ctrl.H(ctrl.ServeGetSimilarSongs))
+	r.Handle("/getSimilarSongs2{_:(?:\\.view)?}", ctrl.H(ctrl.ServeGetSimilarSongsTwo))
 
 	// raw
 	r.Handle("/download{_:(?:\\.view)?}", ctrl.HR(ctrl.ServeDownload))