nixos/wireplumber: init

This is extremely basic for now, but we can add more stuff later

nixos/modules/module-list.nix

@@ -364,6 +364,7 @@
   ./services/desktops/malcontent.nix
   ./services/desktops/pipewire/pipewire.nix
   ./services/desktops/pipewire/pipewire-media-session.nix
+  ./services/desktops/pipewire/wireplumber.nix
   ./services/desktops/gnome/at-spi2-core.nix
   ./services/desktops/gnome/chrome-gnome-shell.nix
   ./services/desktops/gnome/evolution-data-server.nix

nixos/modules/services/desktops/pipewire/wireplumber.nix

@@ -0,0 +1,41 @@
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.services.pipewire.wireplumber;
+in
+{
+  meta.maintainers = [ lib.maintainers.k900 ];
+
+  options = {
+    services.pipewire.wireplumber = {
+      enable = lib.mkEnableOption "A modular session / policy manager for PipeWire";
+
+      package = lib.mkOption {
+        type = lib.types.package;
+        default = pkgs.wireplumber;
+        defaultText = lib.literalExpression "pkgs.wireplumber";
+        description = ''
+          The wireplumber derivation to use.
+        '';
+      };
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    assertions = [
+      {
+        assertion = !config.services.pipewire.media-session.enable;
+        message = "WirePlumber and pipewire-media-session can't be enabled at the same time.";
+      }
+    ];
+
+    environment.systemPackages = [ cfg.package ];
+    systemd.packages = [ cfg.package ];
+
+    systemd.services.wireplumber.enable = config.services.pipewire.systemWide;
+    systemd.user.services.wireplumber.enable = !config.services.pipewire.systemWide;
+
+    systemd.services.wireplumber.wantedBy = [ "pipewire.service" ];
+    systemd.user.services.wireplumber.wantedBy = [ "pipewire.service" ];
+  };
+}