refactor: modularize core

modules/linux/audio/default.nix

@@ -14,8 +14,6 @@ in
   config = {
     services.playerctld.enable = lib.mkIf cfg.enable true;
     hardware.pulseaudio.enable = lib.mkIf cfg.enable false;
-    # TODO: move to other file
-    security.rtkit.enable = true;
     services.pipewire = lib.mkIf cfg.enable {
       enable = true;
       alsa.enable = true;

modules/linux/core/default.nix

@@ -2,9 +2,60 @@
   inputs,
   pkgs,
   config,
+  lib,
   ...
 }:
+let
+  cfg = config.liminalOS.system.core;
+in
 {
+  options.liminalOS.system.core = {
+    enable = lib.mkOption {
+      type = lib.types.bool;
+      default = config.liminalOS.enable;
+      description = ''
+        Whether to enable core liminalOS system utilities and configurations (such as security policies, Nix options, etc)
+      '';
+    };
+    replaceSudoWithDoas = lib.mkOption {
+      type = lib.types.bool;
+      default = cfg.enable;
+      description = ''
+        Whether to replace sudo with doas, the Dedicated OpenBSD Application Subexecutor. Doas is the preferred liminalOS setuid program.
+      '';
+    };
+    waylandFixes = lib.mkOption {
+      type = lib.types.bool;
+      default = cfg.enable;
+      description = ''
+        Whether to enable some Wayland fixes, like setting NIXOS_OZONE_WL to hint Electron apps to use the Wayland windowing system.
+      '';
+    };
+    nixSaneDefaults = lib.mkOption {
+      type = lib.types.bool;
+      default = cfg.enable;
+      description = ''
+        Whether to set sane defaults for Nix, such as optimization and automatic garbage collection.
+      '';
+    };
+    useNh = lib.mkOption {
+      type = lib.types.bool;
+      default = cfg.nixSaneDefaults;
+      description = ''
+        Whether to enable the `nh` cli (yet another Nix helper), a reimplementation of some core NixOS utilities like nix-collect-garbage and nixos-rebuild. If enabled, automatic garbage collection will use `nh` instead of `nix-collect-garbage` and will be able to garbage collect `result` symlinks.
+      '';
+    };
+    flakeLocation = lib.mkOption {
+      type = lib.types.str;
+      default = "";
+      description = ''
+        Absolute filepath location of the NixOS system configuration flake.
+      '';
+    };
+    suppressWarnings = lib.mkEnableOption "suppress warnings";
+  };
+
+  config = lib.mkIf cfg.enable {
     environment.systemPackages = [
       inputs.viminal.packages.${pkgs.system}.default
     ];
@@ -14,13 +65,14 @@
     };
 
     # tells electron apps to use Wayland
-  environment.sessionVariables = {
+    environment.sessionVariables = lib.mkIf cfg.waylandFixes {
       NIXOS_OZONE_WL = "1";
     };
 
-  security.sudo.enable = false;
+    security = {
+      sudo.enable = !cfg.replaceSudoWithDoas;
 
-  security.doas = {
+      doas = lib.mkIf cfg.replaceSudoWithDoas {
         enable = true;
         extraRules = [
           {
@@ -31,15 +83,19 @@
         ];
       };
 
+      rtkit.enable = true;
+    };
+
     services.gnome.gnome-keyring.enable = true;
 
-  nix = {
+    nix = lib.mkIf cfg.nixSaneDefaults {
+      gc = lib.mkIf (!cfg.useNh) {
+        automatic = true;
+        dates = "weekly";
+        options = "--delete-older-than 14d";
+      };
+
       optimise.automatic = true;
-    # gc = {
-    #   automatic = true;
-    #   dates = "weekly";
-    #   options = "--delete-older-than 14d";
-    # };
       # Free up to 1GiB when there is less than 100MiB left
       extraOptions = ''
         min-free = ${toString (100 * 1024 * 1024)}
@@ -62,20 +118,24 @@
       channel.enable = false;
     };
 
-  programs.nh = {
+    programs.nh = lib.mkIf cfg.useNh {
       enable = true;
-    clean.enable = true;
+      clean = lib.mkIf cfg.nixSaneDefaults {
-    clean.extraArgs = "--keep-since 4d --keep 3";
+        enable = true;
-    flake = "/home/youwen/.config/liminalOS";
+        extraArgs = "--keep-since 4d --keep 3";
       };
-  # Enable CUPS to print documents.
+      flake = cfg.flakeLocation;
-  services.printing.enable = true;
-
-  services.avahi = {
-    enable = true;
-    nssmdns4 = true;
-    openFirewall = true;
     };
 
     boot.tmp.cleanOnBoot = true;
+
+    warnings =
+      if !cfg.suppressWarnings && cfg.useNh && cfg.flakeLocation == "" then
+        [
+          ''The `nh` CLI is enabled but `liminalOS.system.core.flakeLocation` is not set. It is recommended that you set this option so that `nh` can work without specifying the flake path every time. You can disable this warning by setting `liminalOS.system.core.suppressWarnings`.''
+        ]
+      else
+        [ ];
+
+  };
 }