implement initial loading of spotify playlists

Playlist can now be added to the initial play queue with the
-playlists command line flag or the playlists yaml key in the
config file.
To load a spotify playlist the link obtained when sharing the playlist
from spotify is used.

6 files changed, 95 insertions, 5 deletions

diff --git a/TODO.md b/TODO.md
index 14f5707..798a1e7 100644
--- a/TODO.md
+++ b/TODO.md
@@ -39,7 +39,7 @@
 - [X] Fix youtube search
 - [ ] Support loading playlists
   - [ ] m3u
-  - [ ] spotify playlist
+  - [X] spotify playlist
 
 ## Configuration
 
diff --git a/config.go b/config.go
index 32b94ca..b2df159 100644
--- a/config.go
+++ b/config.go
@@ -14,6 +14,7 @@ import (
 type Config struct {
 	Port          int            `yaml:"port"`
 	Backends      []string       `yaml:"backends"`
+	Playlists     []string       `yaml:"playlists"`
 	LocalMusicDir string         `yaml:"music-dir"`
 	UploadDir     string         `yaml:"upload-dir"`
 	LogLevel      string         `yaml:"loglevel"`
diff --git a/main.go b/main.go
index 8c70976..c627894 100644
--- a/main.go
+++ b/main.go
@@ -275,12 +275,17 @@ func main() {
 	flag.StringVar(&config.LocalMusicDir,
 		"serve-music-dir", config.LocalMusicDir, "local music directory to serve")
 	flag.StringVar(&config.UploadDir, "upload-dir", config.UploadDir, "directory to upload songs to")
+	playlists := flag.String("playlists", "", "playlists to load")
 	flag.Parse()
 
 	if *backends != "" {
 		config.Backends = strings.Split(*backends, " ")
 	}
 
+	if *playlists != "" {
+		config.Playlists = append(config.Playlists, strings.Split(*playlists, " ")...)
+	}
+
 	llog.SetLogLevelFromString(config.LogLevel)
 	config.HasUpload = slices.Contains(config.Backends, "upload")
 
diff --git a/player.go b/player.go
index 795978b..b8db8fa 100644
--- a/player.go
+++ b/player.go
@@ -20,6 +20,7 @@ type Player interface {
 	Pause()
 	Continue()
 	Stop()
+	LoadPlaylist(playlist string) []*Song
 }
 
 // command struct used to serialize player commands
@@ -253,3 +254,11 @@ func (player *MpvPlayer) Search(pattern map[string]string) chan []*Song {
 
 	return ch
 }
+
+func (player *MpvPlayer) LoadPlaylist(playlist string) (songs []*Song) {
+	if strings.Contains(playlist, "spotify.com") {
+		songs = player.Backends["spotify"].(*SpotifyBackend).loadPlaylist(playlist)
+	}
+
+	return
+}
diff --git a/spotify.go b/spotify.go
index 31adf1b..3e8d962 100644
--- a/spotify.go
+++ b/spotify.go
@@ -194,3 +194,56 @@ func (spotify *SpotifyBackend) Search(patterns map[string]string) []*Song {
 	}
 	return results
 }
+
+func (spotify *SpotifyBackend) loadPlaylist(playlist string) []*Song {
+	playlistIdRegex := regexp.MustCompile(`playlist/.*\?`)
+	match := playlistIdRegex.FindString(playlist)
+	if match == "" {
+		llog.Error("Failed to extract spotify playlist id from %s", playlist)
+	}
+
+	id := match[len("playlist/") : len(match)-1]
+	llog.Debug("Extracted id %s from spotify playlist URI %s", id, playlist)
+
+	// _pl, err := GetPlaylistV2(spotify.session.Mercury(), id)
+	_pl, err := spotify.session.Mercury().GetPlaylist(id)
+	if err != nil {
+		llog.Error("Getting playlist %s failed with %v", playlist, err)
+		return nil
+	}
+
+	plContent := _pl.GetContents()
+	if plContent == nil {
+		llog.Warning("Playlist %s has no content", playlist)
+		return nil
+	}
+
+	plItems := plContent.GetItems()
+	if plItems == nil {
+		llog.Warning("Playlist %s content has no items", playlist)
+		return nil
+	}
+
+	var songs []*Song
+	for _, item := range plItems {
+		uri := item.GetUri()
+		if uri == "" {
+			continue
+		}
+
+
+		uriParts := strings.Split(uri, ":")
+		uri = uriParts[len(uriParts)-1]
+		track, err := spotify.session.Mercury().GetTrack(utils.Base62ToHex(uri))
+		if err != nil {
+			llog.Error("Failed to load track %s: %v", uri, err)
+		}
+
+		s := NewSong(*track.Name, *track.Artist[0].Name, "spotify", uri)
+		s.Album = *track.Album.Name
+		songs = append(songs, s)
+	}
+
+	llog.Debug("Added %d songs from spotify playlist %s", len(songs), _pl.Attributes.GetName())
+	return songs
+}
diff --git a/wrms.go b/wrms.go
index 247ede8..5dfdc53 100644
--- a/wrms.go
+++ b/wrms.go
@@ -54,6 +54,11 @@ func NewWrms(config Config) *Wrms {
 	wrms := Wrms{}
 	wrms.Config = config
 	wrms.Player = NewMpvPlayer(&wrms, config.Backends)
+
+	if len(wrms.Config.Playlists) > 0 {
+		wrms.loadPlaylists(wrms.Config.Playlists)
+	}
+
 	return &wrms
 }
 
@@ -134,6 +139,11 @@ func (wrms *Wrms) Broadcast(ev Event) {
 	})
 }
 
+func (wrms *Wrms) _addSong(song *Song) {
+	wrms.Songs = append(wrms.Songs, song)
+	wrms.queue.Add(song)
+}
+
 func (wrms *Wrms) AddSong(song *Song) {
 	wrms.rwlock.Lock()
 
@@ -144,14 +154,12 @@ func (wrms *Wrms) AddSong(song *Song) {
 		wrms.queue.applyTimeBonus(wrms.Config.timeBonus)
 	}
 
-	wrms.Songs = append(wrms.Songs, song)
-	s := wrms.Songs[len(wrms.Songs)-1]
-	wrms.queue.Add(s)
+	wrms._addSong(song)
 
 	ev := wrms.newEvent("add", []*Song{song})
 	wrms.rwlock.Unlock()
 
-	llog.Info("Added song %s (ptr=%p) to Songs", s.Uri, s)
+	llog.Info("Added song %s (ptr=%p) to Songs", song.Uri, song)
 	wrms.Broadcast(ev)
 
 	if startPlayingAgain {
@@ -343,3 +351,17 @@ func (wrms *Wrms) AdjustSongWeight(connId uuid.UUID, songUri string, vote string
 func (wrms *Wrms) Search(pattern map[string]string) chan []*Song {
 	return wrms.Player.Search(pattern)
 }
+
+func (wrms *Wrms) loadPlaylists(playlists []string) {
+	for _, playlist := range playlists {
+		wrms.appendPlaylist(playlist)
+	}
+}
+
+func (wrms *Wrms) appendPlaylist(playlist string) {
+	songs := wrms.Player.LoadPlaylist(playlist)
+
+	for _, song := range songs {
+		wrms._addSong(song)
+	}
+}