nix/module: toHyprconf -> toHyprlang (#9221)

* nix/module: toHyprconf -> toHyprlang

Updated generator that will end up living in Nixpkgs' `lib/generators`.

* nix/module: use xdph package directly

The downstream module already applies hyprland's
finalPackage to the portalPackage.

* new lib

* lib: add flattenAttrs, remove category processing

Flattening attributes means we no longer need to process categories
separately. For all intents and purposes, they do not exist.

Simplify the codebase once again, while introducing an easy to grasp
recursive function.

Add a bit of documentation for toHyprlang, though I doubt it's clear
enough even now. Still needs proper NixDoc.

* lib: add proper NixDoc

* nix/lib: inherit from lib

nix/module.nix

@@ -5,72 +5,8 @@ inputs: {
   ...
 }: let
   inherit (pkgs.stdenv.hostPlatform) system;
+  selflib = import ./lib.nix lib;
   cfg = config.programs.hyprland;
-
-  # basically 1:1 taken from https://github.com/nix-community/home-manager/blob/master/modules/services/window-managers/hyprland.nix
-  toHyprconf = {
-    attrs,
-    indentLevel ? 0,
-    importantPrefixes ? ["$"],
-  }: let
-    inherit
-      (lib)
-      all
-      concatMapStringsSep
-      concatStrings
-      concatStringsSep
-      filterAttrs
-      foldl
-      generators
-      hasPrefix
-      isAttrs
-      isList
-      mapAttrsToList
-      replicate
-      ;
-
-    initialIndent = concatStrings (replicate indentLevel "  ");
-
-    toHyprconf' = indent: attrs: let
-      sections =
-        filterAttrs (n: v: isAttrs v || (isList v && all isAttrs v)) attrs;
-
-      mkSection = n: attrs:
-        if lib.isList attrs
-        then (concatMapStringsSep "\n" (a: mkSection n a) attrs)
-        else ''
-          ${indent}${n} {
-          ${toHyprconf' "  ${indent}" attrs}${indent}}
-        '';
-
-      mkFields = generators.toKeyValue {
-        listsAsDuplicateKeys = true;
-        inherit indent;
-      };
-
-      allFields =
-        filterAttrs (n: v: !(isAttrs v || (isList v && all isAttrs v)))
-        attrs;
-
-      isImportantField = n: _:
-        foldl (acc: prev:
-          if hasPrefix prev n
-          then true
-          else acc)
-        false
-        importantPrefixes;
-
-      importantFields = filterAttrs isImportantField allFields;
-
-      fields =
-        builtins.removeAttrs allFields
-        (mapAttrsToList (n: _: n) importantFields);
-    in
-      mkFields importantFields
-      + concatStringsSep "\n" (mapAttrsToList mkSection sections)
-      + mkFields fields;
-  in
-    toHyprconf' initialIndent attrs;
 in {
   options = {
     programs.hyprland = {
@@ -106,6 +42,9 @@ in {
           should be written as lists. Variables' and colors' names should be
           quoted. See <https://wiki.hyprland.org> for more examples.
 
+          Special categories (e.g `devices`) should be written as
+          `"devices[device-name]"`.
+
           ::: {.note}
           Use the [](#programs.hyprland.plugins) option to
           declare plugins.
@@ -151,20 +90,21 @@ in {
         '';
       };
 
-      sourceFirst =
-        lib.mkEnableOption ''
-          putting source entries at the top of the configuration
-        ''
-        // {
-          default = true;
-        };
-
-      importantPrefixes = lib.mkOption {
+      topPrefixes = lib.mkOption {
         type = with lib.types; listOf str;
-        default = ["$" "bezier" "name"] ++ lib.optionals cfg.sourceFirst ["source"];
-        example = ["$" "bezier"];
+        default = ["$" "bezier"];
+        example = ["$" "bezier" "source"];
         description = ''
-          List of prefix of attributes to source at the top of the config.
+          List of prefix of attributes to put at the top of the config.
+        '';
+      };
+
+      bottomPrefixes = lib.mkOption {
+        type = with lib.types; listOf str;
+        default = [];
+        example = ["source"];
+        description = ''
+          List of prefix of attributes to put at the bottom of the config.
         '';
       };
     };
@@ -173,38 +113,38 @@ in {
     {
       programs.hyprland = {
         package = lib.mkDefault inputs.self.packages.${system}.hyprland;
-        portalPackage = lib.mkDefault (inputs.self.packages.${system}.xdg-desktop-portal-hyprland.override {
-          hyprland = cfg.finalPackage;
-        });
+        portalPackage = lib.mkDefault inputs.self.packages.${system}.xdg-desktop-portal-hyprland;
       };
     }
     (lib.mkIf cfg.enable {
       environment.etc."xdg/hypr/hyprland.conf" = let
         shouldGenerate = cfg.extraConfig != "" || cfg.settings != {} || cfg.plugins != [];
 
-        pluginsToHyprconf = plugins:
-          toHyprconf {
-            attrs = {
-              plugin = let
-                mkEntry = entry:
-                  if lib.types.package.check entry
-                  then "${entry}/lib/lib${entry.pname}.so"
-                  else entry;
-              in
-                map mkEntry cfg.plugins;
-            };
-            inherit (cfg) importantPrefixes;
+        pluginsToHyprlang = plugins:
+          selflib.toHyprlang {
+            topCommandsPrefixes = cfg.topPrefixes;
+            bottomCommandsPrefixes = cfg.bottomPrefixes;
+          }
+          {
+            plugin = let
+              mkEntry = entry:
+                if lib.types.package.check entry
+                then "${entry}/lib/lib${entry.pname}.so"
+                else entry;
+            in
+              map mkEntry cfg.plugins;
           };
       in
         lib.mkIf shouldGenerate {
           text =
             lib.optionalString (cfg.plugins != [])
-            (pluginsToHyprconf cfg.plugins)
+            (pluginsToHyprlang cfg.plugins)
             + lib.optionalString (cfg.settings != {})
-            (toHyprconf {
-              attrs = cfg.settings;
-              inherit (cfg) importantPrefixes;
-            })
+            (selflib.toHyprlang {
+                topCommandsPrefixes = cfg.topPrefixes;
+                bottomCommandsPrefixes = cfg.bottomPrefixes;
+              }
+              cfg.settings)
             + lib.optionalString (cfg.extraConfig != "") cfg.extraConfig;
         };
     })