network addition

lib/remote/command_dispatch.dart

@@ -0,0 +1,41 @@
+import '../playback/playback_engine.dart';
+import 'messages.dart';
+
+/// Apply a wire [RemoteCommand] to a [PlaybackCommands] target — the single
+/// place the protocol's verbs map onto the playback surface. The host uses it
+/// to drive its local engine from a remote's commands; keeping it transport-
+/// free (no sockets) lets the loopback test exercise the mapping directly.
+Future<void> applyRemoteCommand(
+  PlaybackCommands target,
+  RemoteCommand cmd,
+) async {
+  switch (cmd.op) {
+    case RemoteOp.playPause:
+      await target.togglePlayPause();
+    case RemoteOp.next:
+      await target.next();
+    case RemoteOp.previous:
+      await target.previous();
+    case RemoteOp.seek:
+      await target.seek(Duration(milliseconds: cmd.positionMs ?? 0));
+    case RemoteOp.jumpTo:
+      await target.jumpTo(cmd.index ?? 0);
+    case RemoteOp.playSongs:
+      await target.playSongs(cmd.songs ?? const [],
+          startIndex: cmd.startIndex ?? 0);
+    case RemoteOp.playNext:
+      if (cmd.song != null) await target.playNext(cmd.song!);
+    case RemoteOp.addToQueue:
+      if (cmd.song != null) await target.addToQueue(cmd.song!);
+    case RemoteOp.removeAt:
+      await target.removeAt(cmd.index ?? 0);
+    case RemoteOp.reorder:
+      await target.reorderQueue(cmd.oldIndex ?? 0, cmd.newIndex ?? 0);
+    case RemoteOp.toggleShuffle:
+      await target.toggleShuffle();
+    case RemoteOp.cycleLoop:
+      await target.cycleLoop();
+    case RemoteOp.retry:
+      await target.retry();
+  }
+}