modules/options: add profiles

The next step in the refactoring is to add different profiles, so that
we may toggle them easily in our hosts. Here's the profiles I went for:

- desktop: enables everything a desktop computer needs (graphics,
productivity apps, base apps such as browsers...)
- gaming: enables gaming configurations (steam, gamescope...)
- server: enables server configurations (website hosting, git forge...)

I made sure the server profile can not be enabled if desktop/gaming are
enabled, as it would not make sense to have desktop applications and
configurations on a server.

modules/options/default.nix

@@ -1,5 +1,7 @@
 {
   imports = [
+    ./profiles
+
     ./homeVars.nix
     ./style.nix
     ./systemVars.nix

modules/options/profiles/default.nix

@@ -0,0 +1,7 @@
+{
+  imports = [
+    ./desktop.nix
+    ./gaming.nix
+    ./server.nix
+  ];
+}

modules/options/profiles/desktop.nix

@@ -0,0 +1,18 @@
+{
+  lib,
+  config,
+  ...
+}: let
+  inherit (lib) mkEnableOption;
+in {
+  options = {
+    local.profiles.desktop.enable = mkEnableOption "the desktop profile";
+  };
+
+  config.assertions = [
+    {
+      assertion = !config.local.profiles.server.enable;
+      message = "The desktop profile cannot be enabled if `local.profiles.server.enable` is set to true.";
+    }
+  ];
+}

modules/options/profiles/gaming.nix

@@ -0,0 +1,18 @@
+{
+  lib,
+  config,
+  ...
+}: let
+  inherit (lib) mkEnableOption;
+in {
+  options = {
+    local.profiles.gaming.enable = mkEnableOption "the gaming profile";
+  };
+
+  config.assertions = [
+    {
+      assertion = !config.local.profiles.server.enable;
+      message = "The gaming profile cannot be enabled if `local.profiles.server.enable` is set to true.";
+    }
+  ];
+}

modules/options/profiles/server.nix

@@ -0,0 +1,23 @@
+{
+  lib,
+  config,
+  ...
+}: let
+  inherit (lib) mkEnableOption;
+in {
+  options = {
+    local.profiles.server.enable = mkEnableOption "the server profile";
+  };
+
+  config.assertions = [
+    {
+      assertion = !config.local.profiles.desktop.enable;
+      message = "The server profile cannot be enabled if `local.profiles.desktop.enable` is set to true.";
+    }
+
+    {
+      assertion = !config.local.profiles.gaming.enable;
+      message = "The server profile cannot be enabled if `local.profiles.gaming.enable` is set to true.";
+    }
+  ];
+}