godot: init module and lib

This adds the `programs.godot` module with support for editor
configurations and text editor themes. It's accompanied by the `godot`
library module which exposes constructors for godot data types.

modules/lib/default.nix

@@ -15,4 +15,5 @@ rec {
   shell = import ./shell.nix { inherit lib; };
   zsh = import ./zsh.nix { inherit lib; };
   nushell = import ./nushell.nix { inherit lib; };
+  godot = import ./godot.nix { inherit lib; };
 }

modules/lib/godot.nix

@@ -0,0 +1,76 @@
+{ lib }:
+
+let
+  inherit (lib)
+    concatMapStringsSep escape replaceStrings boolToString floatToString
+    concatStringsSep mapAttrsToList;
+
+  inherit (builtins) mapAttrs;
+
+  mkPrimitive = t: v: {
+    _type = "godotData";
+    type = t;
+    value = v;
+    __toString = self: toString self.value;
+  };
+
+in rec {
+  isGodotData = v: v._type or "" == "godotData";
+
+  mkValue = v:
+    if builtins.isBool v then
+      mkBool v
+    else if builtins.isInt v then
+      mkInt v
+    else if builtins.isFloat v then
+      mkFloat v
+    else if builtins.isString v then
+      mkString v
+    else if builtins.isList v then
+      mkList v
+    else if builtins.isAttrs v && (v._type or "") == "godotData" then
+      v
+    else if builtins.isAttrs v then
+      mkAttrs v
+    else
+      null;
+
+  mkList = elems:
+    mkPrimitive "list" (map mkValue elems) // {
+      __toString = self: "[${concatMapStringsSep ", " toString self.value}]";
+    };
+
+  mkAttrs = attrs:
+    mkPrimitive "attrs" (mapAttrs (name: mkValue) attrs) // {
+      __toString = self:
+        "{${
+          concatStringsSep ", "
+          (mapAttrsToList (name: value: "${mkString name}: ${value}")
+            self.value)
+        }}";
+    };
+
+  mkBool = v:
+    mkPrimitive "bool" v // {
+      __toString = self: boolToString self.value;
+    };
+
+  mkString = v:
+    let
+      sanitize = s: replaceStrings [ "\n" ] [ "\\n" ] (escape [ ''"'' "\\" ] s);
+    in mkPrimitive "string" v // {
+      __toString = self: ''"${sanitize self.value}"'';
+    };
+
+  mkInt = mkPrimitive "int";
+
+  mkFloat = mkPrimitive "float";
+
+  mkCall = name: args:
+    mkPrimitive "call" { inherit name args; } // {
+      __toString = self:
+        "${self.value.name}(${
+          concatMapStringsSep ", " toString self.value.args
+        })";
+    };
+}

modules/modules.nix

@@ -118,6 +118,7 @@ let
     ./programs/gnome-shell.nix
     ./programs/gnome-terminal.nix
     ./programs/go.nix
+    ./programs/godot.nix
     ./programs/gpg.nix
     ./programs/gradle.nix
     ./programs/granted.nix

modules/programs/godot.nix

@@ -0,0 +1,137 @@
+{ config, lib, pkgs, ... }:
+let
+  inherit (lib)
+    literalExpression mkEnableOption mkOption mkIf types hm mapAttrsToList
+    splitString mkOptionDefault singleton concatMapStringsSep mkMerge mapAttrs'
+    nameValuePair;
+
+  inherit (hm.godot) mkValue;
+
+  inherit (builtins) concatStringsSep typeOf toString head;
+
+  cfg = config.programs.godot;
+
+  primitiveType = with types; oneOf [ str int float bool attrs ];
+
+  primitiveTypeOrAttrs = with types;
+    either primitiveType (attrsOf primitiveType);
+
+  composedType = with types;
+    either primitiveTypeOrAttrs (listOf primitiveTypeOrAttrs);
+
+  dataType = with types; coercedTo composedType mkValue attrs;
+
+  # See https://docs.godotengine.org/en/latest/contributing/development/file_formats/tscn.html.
+  genResources = concatMapStringsSep "\n\n" genResource;
+
+  genResource = { type, attributes ? { }, data ? { } }:
+    concatStringsSep "\n" ([
+      (genHeader { inherit type attributes; })
+    ] ++ (mapAttrsToList (name: value: "${name} = ${value}") data));
+
+  genHeader = { type, attributes }:
+    "[${
+      concatStringsSep " " ([ type ]
+        ++ (mapAttrsToList (name: val: "${name}=${mkValue val}") attributes))
+    }]";
+
+in {
+  meta.maintainers = [ hm.maintainers.bricked ];
+
+  options.programs.godot = {
+    enable = mkEnableOption "Godot";
+
+    package = lib.mkPackageOption pkgs "godot_4" { };
+
+    version = lib.mkOption {
+      type = types.str;
+      description = ''
+        Semantic version of the Godot package.
+      '';
+      internal = true;
+    };
+
+    settings = mkOption {
+      type = with types; nullOr (attrsOf dataType);
+      description = ''
+        Attribute set of godot editor settings.
+
+        For a list of available options see https://docs.godotengine.org/en/stable/classes/class_editorsettings.html.
+
+        Primitive values, lists and attrs work as expected. For function calls, 'lib.hm.godot.mkCall name args' is used.
+      '';
+      example = literalExpression ''
+        {
+          "resource_local_to_scene" = false;
+          "interface/editor/editor_language" = "en";
+          "interface/editor/main_font_size" = 14;
+          "interface/theme/accent_color" = lib.hm.godot.mkCall "Color" [ 0.5, 0.5, 1.0, 1.0 ];
+          "text_editor/theme/color_theme" = "Dracula";
+        }'';
+    };
+
+    textThemes = mkOption {
+      type = with types;
+        attrsOf (submodule ({ name, ... }: {
+          options = {
+            name = mkOption {
+              type = types.str;
+              description = ''
+                The name of the text editor theme.
+              '';
+              example = "Dracula";
+              default = name;
+            };
+
+            settings = mkOption {
+              type = with types; attrsOf dataType;
+              description = ''
+                Attribute set of text editor theme data.
+              '';
+              example = {
+                text_color = "cdd6f4ff";
+                number_color = "fab387ff";
+              };
+            };
+          };
+        }));
+      description = ''
+        Attribute set of text editor themes.
+
+        The default text editor theme can be defined using the "text_editor/theme/color_theme" setting.
+      '';
+      default = { };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    programs.godot.version =
+      mkOptionDefault (head (splitString "-" cfg.package.version));
+
+    home.packages = [ cfg.package ];
+
+    xdg.configFile = {
+      "godot/editor_settings-${cfg.version}.tres".text =
+        mkIf (cfg.settings != null) (genResources [
+          {
+            type = "gd_resource";
+            attributes = {
+              type = "EditorSettings";
+              format = 3;
+            };
+          }
+
+          {
+            type = "resource";
+            data = cfg.settings;
+          }
+        ]);
+    } // mapAttrs' (name: theme:
+      nameValuePair "godot/text_editor_themes/${theme.name}.tet" {
+        text = genResource {
+          type = "color_theme";
+          data = theme.settings;
+        };
+      }) cfg.textThemes;
+  };
+}