chore(Nix): add Makefile steps for building nix package

.gitignore

@@ -7,3 +7,4 @@ dist
 settings.mk
 RyzenAdj
 .gut_editor_config.json
+result

Makefile

@@ -270,6 +270,28 @@ deploy-ext: dist-ext ## Build and deploy systemd extension to remote device
 	ssh $(SSH_USER)@$(SSH_HOST) systemd-sysext status
 
 
+.PHONY: deploy-nix
+deploy-nix: dist-nix ## Build and deploy the nix package to a remote device
+	nix copy $$(cat ./dist/opengamepadui.nix) --to ssh://$(SSH_USER)@$(SSH_HOST)
+	@echo "Copied OpenGamepadUI package: $$(cat ./dist/opengamepadui.nix)"
+	@echo "Modifying config to use package"
+	@DEPLOY_SCRIPT=$$(mktemp); set -e; \
+		echo "set -ex" >> $$DEPLOY_SCRIPT; \
+		echo "echo 'Removing old package references'" >> $$DEPLOY_SCRIPT; \
+	  echo "sed -i '/.*programs.opengamepadui.package.*/d' /etc/nixos/configuration.nix" >> $$DEPLOY_SCRIPT; \
+		echo "echo 'Setting opengamepadui package in /etc/nixos/configuration.nix'" >> $$DEPLOY_SCRIPT; \
+		echo "sed -i 's|^}|  programs.opengamepadui.package = $$(cat ./dist/opengamepadui.nix);\n}|g' /etc/nixos/configuration.nix" >> $$DEPLOY_SCRIPT; \
+		echo "echo 'Applying new configuration'" >> $$DEPLOY_SCRIPT; \
+		echo "nixos-rebuild switch --impure" >> $$DEPLOY_SCRIPT; \
+		echo "echo 'Applying new configuration'" >> $$DEPLOY_SCRIPT; \
+		echo "rm $$DEPLOY_SCRIPT" >> $$DEPLOY_SCRIPT; \
+		echo "Copying deployment script to target device"; \
+		scp $$DEPLOY_SCRIPT $(SSH_USER)@$(SSH_HOST):$$DEPLOY_SCRIPT; \
+		echo "Executing deployment script"; \
+		ssh -t $(SSH_USER)@$(SSH_HOST) sudo bash $$DEPLOY_SCRIPT; \
+		rm $$DEPLOY_SCRIPT
+
+
 .PHONY: enable-debug
 enable-debug: ## Set OpenGamepadUI command to use remote debug on target device
 	ssh $(SSH_USER)@$(SSH_HOST) mkdir -p .config/environment.d
@@ -336,6 +358,18 @@ dist/update.zip: build/metadata.json
 	cp $(CACHE_DIR)/update.zip $@
 
 
+.PHONY: dist-nix
+dist-nix: dist/opengamepadui.nix ## Create a nix package
+dist/opengamepadui.nix: $(IMPORT_DIR) $(PROJECT_FILES)
+	@echo "Building nix package"
+	mkdir -p dist
+	nix build --impure \
+		--expr 'with import (builtins.getFlake "gitlab:shadowapex/os-flake?ref=main").inputs.nixpkgs {}; callPackage ./package/nix/package.nix {}'
+	echo $$(file result | cut -d' ' -f5) > $@
+	@rm result
+	@echo "Built OpenGamepadUI package: $$(cat ./dist/opengamepadui.nix)"
+
+
 # https://blogs.igalia.com/berto/2022/09/13/adding-software-to-the-steam-deck-with-systemd-sysext/
 .PHONY: dist-ext
 dist-ext: dist/opengamepadui.raw ## Create a systemd-sysext extension archive

package/nix/package.nix

@@ -0,0 +1,92 @@
+{
+  cargo,
+  gamescope,
+  godot_4_4,
+  hwdata,
+  lib,
+  mesa-demos,
+  nix-update-script,
+  pkg-config,
+  rustPlatform,
+  stdenv,
+  udev,
+  upower,
+  withDebug ? false,
+}:
+
+stdenv.mkDerivation (finalAttrs: {
+  pname = "opengamepadui";
+  version = "latest";
+
+  buildType = if withDebug then "debug" else "release";
+
+  src = ../..;
+
+  cargoDeps = rustPlatform.fetchCargoVendor {
+    inherit (finalAttrs) src;
+    sourceRoot = "OpenGamepadUI/${finalAttrs.cargoRoot}";
+    hash = "sha256-vgaa7Pe0lksiGEpQbn2he5CzhVWoHUSPuXqCwSkoDco=";
+  };
+  cargoRoot = "extensions";
+
+  nativeBuildInputs = [
+    cargo
+    godot_4_4
+    pkg-config
+    rustPlatform.cargoSetupHook
+  ];
+
+  dontStrip = withDebug;
+
+  env =
+    let
+      versionAndRelease = lib.splitString "-" godot_4_4.version;
+    in
+    {
+      GODOT = lib.getExe godot_4_4;
+      GODOT_VERSION = lib.elemAt versionAndRelease 0;
+      GODOT_RELEASE = lib.elemAt versionAndRelease 1;
+      EXPORT_TEMPLATE = "${godot_4_4.export-template}/share/godot/export_templates";
+      BUILD_TYPE = "${finalAttrs.buildType}";
+    };
+
+  makeFlags = [ "PREFIX=$(out)" ];
+
+  buildFlags = [ "build" ];
+
+  preBuild = ''
+    # Godot looks for export templates in HOME
+    export HOME=$(mktemp -d)
+    mkdir -p $HOME/.local/share/godot/
+    ln -s "$EXPORT_TEMPLATE" "$HOME"/.local/share/godot/
+    make clean
+  '';
+
+  postInstall =
+    let
+      runtimeDependencies = [
+        gamescope
+        hwdata
+        mesa-demos
+        udev
+        upower
+      ];
+    in
+    ''
+      # The Godot binary looks in "../lib" for gdextensions
+      mkdir -p $out/share/lib
+      mv $out/share/opengamepadui/*.so $out/share/lib
+      patchelf --add-rpath ${lib.makeLibraryPath runtimeDependencies} $out/share/lib/*.so
+    '';
+
+  passthru.updateScript = nix-update-script { };
+
+  meta = {
+    description = "Open source gamepad-native game launcher and overlay";
+    homepage = "https://github.com/ShadowBlip/OpenGamepadUI";
+    license = lib.licenses.gpl3Only;
+    platforms = [ "x86_64-linux" ];
+    maintainers = with lib.maintainers; [ shadowapex ];
+    mainProgram = "opengamepadui";
+  };
+})