Allow configuring languages

lib/modules/i18n.nix

@@ -0,0 +1,27 @@
+{ lib, config, ... }:
+  let
+    inherit (lib)
+      types
+    ;
+
+    cfg = config.i18n;
+  in {
+    options = {
+      i18n = {
+        localeSettings = {
+          type = types.attrsOf types.str;
+          description = "The system wide locale settings";
+          default = {};
+        };
+
+        locales = {
+          type = types.listOf types.str;
+          description = "The locales of the system";
+        };
+      };
+    };
+
+    config = {
+      locales = builtins.attrValues cfg.localeSettings;
+    };
+  }

profiles/Generic/config.nix

@@ -4,6 +4,7 @@
   in {
     imports = [
       ../../lib/modules/partition.nix
+      ../../lib/modules/i18n.nix
     ];
 
     config = {
@@ -32,5 +33,15 @@
           };
         };
       };
+
+      i18n = {
+        localeSettings =
+          let defaultLocale = "en_US.UTF-8";
+          in {
+            LANG = "de_CH.UTF-8";
+            LANGUAGE = defaultLocale;
+            LC_MESSAGE = defaultLocale;
+          };
+      };
     };
   }