From e3350bd17d42edf1b18bfe06b44b7920bb1adc91 Mon Sep 17 00:00:00 2001
From: Gabriel Arazas <foodogsquared@foodogsquared.one>
Date: Tue, 25 Jun 2024 22:41:17 +0800
Subject: [PATCH] nixos/programs/gnome-session: fix session settings format and
 submodule module argument passing

---
 .../nixos/programs/gnome-session/default.nix  | 36 ++++++++++++++-----
 .../gnome-session/submodules/session-type.nix | 17 ++++-----
 2 files changed, 37 insertions(+), 16 deletions(-)

diff --git a/modules/nixos/programs/gnome-session/default.nix b/modules/nixos/programs/gnome-session/default.nix
index 8c387130..2afdbd94 100644
--- a/modules/nixos/programs/gnome-session/default.nix
+++ b/modules/nixos/programs/gnome-session/default.nix
@@ -8,15 +8,33 @@
 let
   cfg = config.programs.gnome-session;
 
+  # The gnome-session config files uses one from GLib. See the following link
+  # at <https://docs.gtk.org/glib/struct.KeyFile.html> for details about the
+  # keyfile formatting and possibly the Desktop Entry specification at
+  # <https://freedesktop.org/wiki/Specifications/desktop-entry-spec>.
   glibKeyfileFormat = pkgs.formats.ini {
     listsAsDuplicateKeys = false;
-    mkKeyValue =
+    mkKeyValue = lib.generators.mkKeyValueDefault {
+      mkValueString = v:
+        if lib.isList v then
+          lib.concatStringsSep ";" v
+        else
+          lib.generators.mkValueStringDefault { } v;
+    } "=";
+  } // {
+    type = with lib.types;
       let
-        mkValueString = lib.generators.mkKeyValueDefault { };
+        valueType = oneOf [
+          bool
+          float
+          int
+          str
+          (listOf valueType)
+        ] // {
+          description = "GLib keyfile atom (null, bool, int, float, string, or a list of the previous atoms)";
+        };
       in
-        k: v:
-          if lib.isList v then lib.concatStringsSep ";" v
-          else "${k}=${mkValueString v}";
+        attrsOf (attrsOf valueType);
   };
 
   # The bulk of the work. Pretty much the main purpose of this module.
@@ -25,13 +43,14 @@ let
       let
         gnomeSession = glibKeyfileFormat.generate "session-${session.name}" session.settings;
 
+        # For now, we set this as a 
         displaySession = ''
           [Desktop Entry]
-          Name=@fullName@
+          Name=${session.fullName}
           Comment=${session.description}
           Exec="@out@/libexec/${session.name}-session"
           Type=Application
-          DesktopNames=${lib.concatStringsSep ";" session.desktopNames};
+          DesktopNames=${lib.concatStringsSep ";" session.desktopNames}
         '';
 
         sessionScript = ''
@@ -76,6 +95,7 @@ let
 
           DISPLAY_SESSION_FILE="$out/share/wayland-sessions/${session.name}.desktop"
           install -Dm0644 "$displaySessionPath" "$DISPLAY_SESSION_FILE"
+          substituteAllInPlace "$DISPLAY_SESSION_FILE"
 
           ${lib.concatStringsSep "\n" installDesktopFiles}
         ''
@@ -122,7 +142,7 @@ in
 
     sessions = lib.mkOption {
       type = with lib.types; attrsOf (submoduleWith {
-        specialArgs = { inherit utils glibKeyfileFormat; };
+        specialArgs = { inherit utils glibKeyfileFormat pkgs; };
         modules = [ ./submodules/session-type.nix ];
       });
       description = ''
diff --git a/modules/nixos/programs/gnome-session/submodules/session-type.nix b/modules/nixos/programs/gnome-session/submodules/session-type.nix
index 564bb488..f87c5198 100644
--- a/modules/nixos/programs/gnome-session/submodules/session-type.nix
+++ b/modules/nixos/programs/gnome-session/submodules/session-type.nix
@@ -1,7 +1,6 @@
-{ name, config, lib, utils, glibKeyfileFormat, ... }:
+{ name, config, pkgs, lib, utils, glibKeyfileFormat, ... }:
 
 let
-
   # For an updated list, see `menu/menu-spec.xml` from
   # https://gitlab.freedesktop.org/xdg/xdg-specs.
   validDesktopNames = [
@@ -92,7 +91,7 @@ in
     components = lib.mkOption {
       type = with lib.types; attrsOf (submoduleWith {
         specialArgs = {
-          inherit utils;
+          inherit utils pkgs;
           session = {
             inherit (config) fullName desktopNames description;
             inherit name;
@@ -147,11 +146,13 @@ in
       '';
       example = lib.literalExpression ''
         {
-          # A helper script to check if the session is runnable.
-          IsRunnableHelper = "''${lib.getExe' pkgs.niri "niri"} --validate config";
+          "GNOME Session" = {
+            # A helper script to check if the session is runnable.
+            IsRunnableHelper = "''${lib.getExe' pkgs.niri "niri"} --validate config";
 
-          # A fallback session in case it failed.
-          FallbackSession = "gnome";
+            # A fallback session in case it failed.
+            FallbackSession = "gnome";
+          };
         }
       '';
     };
@@ -227,7 +228,7 @@ in
     };
 
     settings."GNOME Session" = {
-      Name = "${config.fullName} session";
+      Name = lib.mkDefault "${config.fullName} session";
       RequiredComponents = config.requiredComponents;
     };
   };