Make Queue.current nullable, since MPD may be stopped

schemata/playback-v1.json

@@ -104,7 +104,7 @@
 		"Queue": {
 			"properties": {
 				"current": {
-					"description": "The zero-based index of the current song in MPD's queue.",
+					"description": "The zero-based index of the current song in MPD's queue. If MPD is currently stopped, then there is no current song in the queue, indicated by None.",
 					"title": "Current",
 					"type": "integer"
 				},

src/mpd_now_playable/mpd/convert/to_playback.py

@@ -9,8 +9,8 @@ from .to_song import to_song
 
 def to_queue(mpd: MpdState) -> Queue:
 	return Queue(
-		current=int(mpd.current["pos"]),
-		next=int(mpd.status["nextsong"]),
+		current=option_fmap(int, mpd.current.get("pos")),
+		next=int(mpd.status.get("nextsong", 0)),
 		length=int(mpd.status["playlistlength"]),
 	)
 

src/mpd_now_playable/playback/queue.py

@@ -3,8 +3,10 @@ from dataclasses import dataclass
 
 @dataclass(slots=True)
 class Queue:
-	#: The zero-based index of the current song in MPD's queue.
-	current: int
+	#: The zero-based index of the current song in MPD's queue. If MPD is
+	#: currently stopped, then there is no current song in the queue, indicated
+	#: by None.
+	current: int | None
 	#: The index of the next song to be played, taking into account random and
 	#: repeat playback settings.
 	next: int