modules: users: add systemType and isGraphical options

systemType describes the type of a system, e.g. a laptop,
desktop or server. 

isGraphical takes this to determine whether a system needs
programs such as a compositor, graphical applications etc.

modules/options/system/module.nix

@@ -5,7 +5,10 @@
 }: let
   inherit (builtins) elemAt;
   inherit (lib.options) mkOption mkEnableOption;
-  inherit (lib.types) enum listOf str nullOr bool package;
+  inherit (lib.types) enum listOf str nullOr bool oneOf;
+  inherit (lib.lists) elem;
+
+  inherit (config.modules.system) systemType;
 in {
   imports = [
     # configuration options for nixos activation scripts
@@ -44,7 +47,7 @@ in {
 
     users = mkOption {
       type = listOf str;
-      default = ["charlie"];
+      default = ["cr"];
       description = "A list of  users on the system.";
     };
 
@@ -57,6 +60,23 @@ in {
       '';
     };
 
+    systemType = mkOption {
+      type = nullOr (enum ["desktop" "laptop" "server"]);
+      default = null;
+      description = ''
+        The type of the current system. This is used to determine whether things like graphical
+        environments and power-saving programs should be installed or not.
+      '';
+    };
+
+    isGraphical = mkOption {
+      type = bool;
+      default = elem systemType ["desktop" "laptop"];
+      description = ''
+        Whether the current system is a graphical system.
+      '';
+    };
+
     yubikeySupport = {
       enable = mkEnableOption "yubikey support";
       deviceType = mkOption {
@@ -72,6 +92,7 @@ in {
     impermanence = {
       enable = mkEnableOption "Enable Impermanence";
     };
+
     video = {
       enable = mkEnableOption "video drivers and programs that require a graphical user interface";
       nvidia = mkEnableOption "Nvidia graphics drivers";
@@ -92,15 +113,6 @@ in {
         default = [];
         description = "A list of extra drivers to enable for printing";
       };
-
-      "3d" = {
-        enable = mkEnableOption "3D printing suite";
-        extraPrograms = mkOption {
-          type = listOf package;
-          default = [];
-          description = "A list of extra programs to enable for 3D printing";
-        };
-      };
     };
   };
 }

modules/other/users.nix

@@ -7,7 +7,7 @@
 }: let
   inherit (builtins) elemAt;
   inherit (lib.options) mkOption;
-  inherit (lib.types) listOf str;
+  inherit (lib.types) listOf str package;
 
   inherit (config.meta.mainUser) username;
 in {
@@ -27,6 +27,7 @@ in {
           The main user for each system. This is the first element of the list of users by default.
         '';
       };
+
       gitSigningKey = mkOption {
         type = str;
         description = ''
@@ -36,9 +37,28 @@ in {
           ecdsa-sha2-nistp521 AAAAE2VjZHNhLXNoYTItbmlzdHA1MjEAAAAIbmlzdHA1MjEAAACFBAAWEDj/Yib6Mqs016jx7rtecWpytwfVl28eoHtPYCM9TVLq81VIHJSN37lbkc/JjiXCdIJy2Ta3A3CVV5k3Z37NbgAu23oKA2OcHQNaRTLtqWlcBf9fk9suOkP1A3NzAqzivFpBnZm3ytaXwU8LBJqxOtNqZcFVruO6fZxJtg2uE34mAw==
         '';
       };
+
+      # TODO: clean this up and move it somewhere else.
+      defaultShell = {
+        name = mkOption {
+          type = str;
+          default = "nushell";
+          description = ''
+            The default shell of a user. This is not the main system shell, but the shell used in terminals.
+          '';
+        };
+        package = mkOption {
+          type = package;
+          default = pkgs.nushell;
+        };
+      };
     };
   };
   config = {
+    programs.zsh = {
+      enable = true;
+      enableBashCompletion = true;
+    };
     users = {
       mutableUsers = true;
       users = {
@@ -53,6 +73,7 @@ in {
             "nix"
             "docker"
           ];
+          # shell = self.packages.${pkgs.stdenv.system}.fish;
           shell = pkgs.zsh;
           # hashedPasswordFile = "/etc/passwords/cr";
         };