support maximum songs per playlist config

config.gcfg

@@ -26,6 +26,10 @@ DefaultComment = "Hello! I am a bot. Type !help for a list of commands."
 # Default Value: 0
 MaxSongDuration = 0
 
+# Maximum songs per playlist (0 = unrestricted)
+# Default Value: 50
+MaxSongPerPlaylist = 50
+
 # Is playlist shuffling enabled when the bot starts?
 # Default Value: false
 AutomaticShuffleOn = false

parseconfig.go

@@ -22,6 +22,7 @@ type DjConfig struct {
 		PlaylistSkipRatio   float32
 		DefaultComment      string
 		MaxSongDuration     int
+		MaxSongPerPlaylist  int
 		AutomaticShuffleOn  bool
 	}
 	Cache struct {

service_youtube.go

@@ -173,9 +173,17 @@ func (yt YouTube) NewPlaylist(user *gumble.User, id string) ([]Song, error) {
 				songArray = append(songArray, song)
 			}
 		}
-		if pageToken, err = apiResponse.String("nextPageToken"); err != nil{
+		if pageToken, err = apiResponse.String("nextPageToken"); err != nil || playlistSizeExceeded(songArray) {
 			morePages = false
 		}
 	}
+	if (dj.conf.General.MaxSongPerPlaylist > 0 && len(songArray) > dj.conf.General.MaxSongPerPlaylist){
+		songArray = songArray[:dj.conf.General.MaxSongPerPlaylist]
+	}
 	return songArray, nil
 }
+
+// checks if the number of songs of the playlist exceeds the configured playlist maximum size
+func playlistSizeExceeded(songs []Song) bool{
+	return dj.conf.General.MaxSongPerPlaylist > 0 && len(songs) > dj.conf.General.MaxSongPerPlaylist
+}