add: more system modules

system/modules/user/default.nix

@@ -0,0 +1,14 @@
+{ lib, ... }:
+
+{
+  imports = [
+    ./shell
+    ./ooks.nix
+  ];
+
+  options.systemModules.user = {
+    ooks = {
+      enable = lib.mkEnableOption "Enable the user ooks";
+    };
+  };  
+}

system/modules/user/ooks.nix

@@ -0,0 +1,28 @@
+{ lib, pkgs, config, ... }:
+
+let 
+  ifTheyExist = groups: builtins.filter (group: builtins.hasAttr group config.users.groups) groups;
+  cfg = config.systemModule.user.ooks;
+in
+
+{
+  config = lib.mkIf cfg.enable {
+    users.users.ooks = {
+      isNormalUser = true;
+      extraGroups = [
+      "wheel"
+      "video"
+      "audio"
+      ] ++ ifTheyExist [
+      "git"
+      "network"
+      "libvirtd"
+      "deluge"
+      ];
+
+    packages = [ pkgs.home-manager ];
+    };
+
+    home-manager.users.ooks = import ../../../../home/user/ooks/${config.networking.hostName};
+  };
+}

system/modules/user/shell/default.nix

@@ -0,0 +1,40 @@
+{ lib, config, ... }:
+
+let
+  cfg = config.systemModules.user.shell;
+in
+
+{
+  imports = [
+    ./fish
+    # ./bash
+    # ./zsh
+  ];
+
+  options.systemModules.user.shell = {
+    fish = {
+      enable = lib.mkEnableOption "Enable fish as the user shell";
+    };
+    zsh = {
+      enable = lib.mkEnableOption "Enable zsh as the user shell";
+    };
+    bash = {
+      enable = lib.mkEnableOption "Enable bash as the user shell";
+    };
+
+  };
+
+   config = { 
+    assertions = [
+      {
+        assertion = 
+          (lib.length (lib.filter (x: x) [
+            cfg.fish.enable or false
+            cfg.zsh.enable or false
+            cfg.bash.enable or false
+          ]) <= 1); 
+        message = "Only one user shell can be active in the configuration";
+      }
+    ];
+  };
+}

system/modules/user/shell/fish/default.nix

@@ -0,0 +1,19 @@
+{ pkgs, lib, config, ... }:
+
+let
+  cfg = config.systemModules.user.shell.fish;
+in
+
+{
+  config = lib.mkIf cfg.enable {
+    users.users.ooks.shell = pkgs.fish;
+    programs.fish = {
+      enable = true;
+      vendor = {
+        completions.enable = true;
+        config.enable = true;
+        functions.enable = true;
+      };
+    };
+  };
+}