hosts/desktop: configure Mopidy server

hosts/desktop/default.nix

@@ -1,5 +1,38 @@
 { config, lib, pkgs, ... }:
 
+let
+  musicDir = "/srv/music";
+  playlistsDir = "${musicDir}/playlists";
+in
 {
+  services.mopidy = {
+    enable = true;
+    extensionPackages = with pkgs; [
+      mopidy-iris
+      mopidy-local
+      mopidy-mpd
+      mopidy-mpris
+      mopidy-youtube
+    ];
+
+    configuration = ''
+      [http]
+      hostname = 172.23.0.1
+      port = 6669
+
+      [file]
+      enabled = true
+      media_dirs =
+        ${musicDir}|Music
+
+      [m3u]
+      enabled = true
+      base_dir = ${musicDir}
+      playlists_dir = ${playlistsDir}
+      default_encoding = utf-8
+      default_extension = .m3u8
+    '';
+  };
+
   system.stateVersion = "23.05";
 }