services/foldingathome: add fah module

modules/modules/services/foldingathome.nix

@@ -0,0 +1,32 @@
+{ config, lib, ... }:
+with lib;
+with lib.hlissner;
+let
+  cfg = config.modules.services.foldingathome;
+in
+{
+  options.modules.services.foldingathome = with types; {
+    enable = mkBoolOpt false;
+    user = mkOpt str config.user.name;
+    daemonNiceLevel = mkOpt int 10;
+    extra = {
+      control = mkBoolOpt false;
+      viewer = mkBoolOpt false;
+    };
+  };
+
+  config = mkMerge [
+    (mkIf cfg.enable {
+      services.foldingathome = {
+        enable = true;
+        user = cfg.user;
+        daemonNiceLevel = cfg.daemonNiceLevel;
+      };
+
+      environment.systemPackages = with pkgs; [
+        (optional cfg.extra.control fahcontrol)
+        (optional cfg.extra.viewer fahviewer)
+      ];
+    })
+  ];
+}