write mkConfWrapper function for helix

this makes helix use the user config instead, if it exists

cli/helix.nix

@@ -2,6 +2,7 @@
   pkgs,
   lib,
   config,
+  owoLib,
   ...
 }:
 
@@ -33,15 +34,9 @@ in
 
   config = lib.mkIf cfg.enable {
     environment.systemPackages = [
-      (pkgs.symlinkJoin {
-        inherit name;
-        paths = [ cfg.package ];
-        nativeBuildInputs = [ pkgs.makeWrapper ];
-        postBuild = ''
-          wrapProgram $out/bin/hx \
-            --add-flags "-c" \
-            --add-flags "${pkgs.writeText "${name}.toml" cfg.extraConfig}"
-        '';
+      (owoLib.mkConfWrapper "hx" cfg.package {
+        globalConfig = pkgs.writeText "${name}.toml" cfg.extraConfig;
+        userConfig = "$HOME/${name}/config.toml";
       })
     ];
 

default.nix

@@ -1,5 +1,6 @@
 {
   lib,
+  pkgs,
   config,
   ...
 }:
@@ -18,8 +19,12 @@ in
     enable = lib.mkEnableOption "common settings";
   };
 
-  config = lib.mkIf cfg.enable {
-    nixowos.cli.enable = true;
-    nixowos.system.enable = true;
+  config = {
+    _module.args.owoLib = pkgs.callPackage ./lib { };
+
+    nixowos = lib.mkIf cfg.enable {
+      cli.enable = true;
+      system.enable = true;
+    };
   };
 }

lib/default.nix

@@ -0,0 +1,28 @@
+{
+  pkgs,
+  ...
+}:
+
+{
+  mkConfWrapper =
+    name: package:
+    {
+      globalConfig,
+      userConfig ? "$HOME/${name}/${name}.conf",
+      configArg ? "-c ",
+      excecutable ? "${package}/bin/${name}",
+    }:
+    pkgs.writeShellApplication {
+      inherit name;
+
+      runtimeInputs = [ package ];
+
+      text = ''
+        if test -r "${userConfig}"; then
+          exec -a "$0" "${excecutable}" "$@"
+        else
+          exec -a "$0" "${excecutable}" ${configArg}"${globalConfig}" "$@"
+        fi
+      '';
+    };
+}