Fix htop for darwin

A shim for programs.htop

modules/tools.nix

@@ -1,30 +1,12 @@
-{ pkgs, ... }:
 {
-  environment.systemPackages = with pkgs; [
-    vim
-    git
-    jq
+  lib,
+  options,
+  pkgs,
+  ...
+}:
 
-    # Nix
-    nix-output-monitor # nix build -> nom build
-
-    # Software debug
-    tcpdump
-    lsof
-    ncdu
-    nmap
-    lnav
-    wakeonlan
-
-    # Hardware info and tunables
-    smartmontools # smartctl
-    usbutils # lsusb
-    pciutils # lspci
-  ];
-
-  programs.htop = {
-    enable = true;
-    settings = {
+let
+  htopSettings = {
     # Header
     header_margin = false;
     detailed_cpu_time = true;
@@ -47,5 +29,53 @@
     highlight_base_name = true;
     tree_view = true;
   };
+  hasHtopOption = options ? programs.htop;
+in
+lib.mkMerge [
+  {
+    environment.systemPackages = with pkgs; [
+      vim
+      git
+      jq
+
+      # Nix
+      nix-output-monitor # nix build -> nom build
+
+      # Software debug
+      tcpdump
+      lsof
+      ncdu
+      nmap
+      lnav
+      wakeonlan
+
+      # Hardware info and tunables
+      smartmontools # smartctl
+      usbutils # lsusb
+      pciutils # lspci
+    ];
+  }
+
+  (lib.optionalAttrs hasHtopOption {
+    programs.htop = {
+      enable = true;
+      settings = htopSettings;
     };
-}
+  })
+
+  (lib.optionalAttrs (!hasHtopOption) {
+    environment.systemPackages = [ pkgs.htop ];
+    environment.etc."htoprc".text =
+      let
+        serialize =
+          val:
+          if lib.isBool val then
+            (if val then "1" else "0")
+          else if lib.isList val then
+            lib.concatStringsSep " " val
+          else
+            toString val;
+      in
+      lib.concatStringsSep "\n" (lib.mapAttrsToList (k: v: "${k}=${serialize v}") htopSettings) + "\n";
+  })
+]