feat: add Nix flake for native build PyQt5

flake.nix

@@ -0,0 +1,177 @@
+{
+  description = "Vial - Open-source GUI for configuring QMK keyboards";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-parts.url = "github:hercules-ci/flake-parts";
+  };
+
+  outputs =
+    inputs@{ flake-parts, ... }:
+    flake-parts.lib.mkFlake { inherit inputs; } {
+      systems = [
+        "x86_64-linux"
+        "aarch64-linux"
+      ];
+
+      perSystem =
+        { pkgs, self', ... }:
+        let
+          pythonEnv = pkgs.python3.withPackages (
+            ps: with ps; [
+              pyqt5
+              hidapi
+              simpleeval
+              certifi
+            ]
+          );
+
+          # fbs_runtime shim files
+          fbsRuntimeInit = pkgs.writeText "fbs_runtime__init__.py" ''
+            # fbs_runtime shim for running without fbs
+          '';
+
+          fbsAppContextInit = pkgs.writeText "fbs_runtime_application_context__init__.py" ''
+            # fbs_runtime.application_context shim
+            from functools import cached_property
+
+            def is_frozen():
+                return False
+          '';
+
+          fbsAppContextPyQt5 = pkgs.writeText "fbs_runtime_application_context_PyQt5.py" ''
+            # fbs_runtime.application_context.PyQt5 shim
+            import sys
+            import os
+            from functools import lru_cache
+            from PyQt5 import QtWidgets, QtGui
+
+            def cached_property(getter):
+                return property(lru_cache()(getter))
+
+            class ApplicationContext:
+                def __init__(self):
+                    # Access app to ensure QApplication is created first
+                    self.app
+
+                @cached_property
+                def app(self):
+                    result = QtWidgets.QApplication(sys.argv)
+                    result.setApplicationName(self.build_settings["app_name"])
+                    result.setApplicationVersion(self.build_settings["version"])
+                    return result
+
+                @cached_property
+                def build_settings(self):
+                    return {
+                        "app_name": "Vial",
+                        "version": "0.8.0-ilc",
+                    }
+
+                def get_resource(self, *path):
+                    # Resources are in the share/vial directory (where main.py is)
+                    # __file__ is fbs_runtime/application_context/PyQt5.py
+                    # So we need to go up 3 levels to get to share/vial
+                    base = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+                    return os.path.join(base, *path)
+          '';
+        in
+        {
+          packages = {
+            default = self'.packages.vial;
+
+            vial = pkgs.stdenv.mkDerivation {
+              pname = "vial";
+              version = "0.8.0-ilc";
+
+              src = ./.;
+
+              nativeBuildInputs = with pkgs; [
+                qt5.wrapQtAppsHook
+                makeWrapper
+              ];
+
+              buildInputs = with pkgs; [
+                qt5.qtbase
+                libusb1
+              ];
+
+              qtWrapperArgs = [
+                "--unset QT_STYLE_OVERRIDE"
+              ];
+
+              propagatedBuildInputs = [ pythonEnv ];
+
+              dontBuild = true;
+
+              installPhase = ''
+                runHook preInstall
+
+                mkdir -p $out/share/vial
+                cp -r src/main/python/* $out/share/vial/
+                cp -r src/main/resources/base/* $out/share/vial/
+
+                # Create fbs_runtime shim
+                mkdir -p $out/share/vial/fbs_runtime/application_context
+                cp ${fbsRuntimeInit} $out/share/vial/fbs_runtime/__init__.py
+                cp ${fbsAppContextInit} $out/share/vial/fbs_runtime/application_context/__init__.py
+                cp ${fbsAppContextPyQt5} $out/share/vial/fbs_runtime/application_context/PyQt5.py
+
+                # Create launcher script
+                mkdir -p $out/bin
+                makeWrapper ${pythonEnv}/bin/python $out/bin/vial \
+                  --add-flags "$out/share/vial/main.py"
+
+                # udev rules
+                mkdir -p $out/etc/udev/rules.d
+                echo 'KERNEL=="hidraw*", SUBSYSTEM=="hidraw", MODE="0666", TAG+="uaccess", TAG+="udev-acl"' > $out/etc/udev/rules.d/92-vial.rules
+
+                # Desktop entry
+                mkdir -p $out/share/applications
+                cat > $out/share/applications/vial.desktop << DESKTOP
+                [Desktop Entry]
+                Name=Vial
+                Comment=Configure your QMK keyboard
+                Exec=$out/bin/vial
+                Icon=vial
+                Terminal=false
+                Type=Application
+                Categories=Utility;
+                DESKTOP
+
+                # Icons (if available)
+                if [ -d "src/main/icons" ]; then
+                  mkdir -p $out/share/icons
+                  cp -r src/main/icons/* $out/share/icons/
+                fi
+
+                runHook postInstall
+              '';
+
+              dontWrapQtApps = false;
+
+              preFixup = ''
+                wrapQtApp $out/bin/vial
+              '';
+
+              meta = with pkgs.lib; {
+                description = "Open-source GUI for configuring QMK keyboards in real time";
+                homepage = "https://get.vial.today";
+                license = licenses.gpl2Plus;
+                platforms = platforms.linux;
+                mainProgram = "vial";
+              };
+            };
+          };
+
+          devShells.default = pkgs.mkShell {
+            packages = [
+              pythonEnv
+              pkgs.qt5.qtbase
+            ];
+
+            QT_QPA_PLATFORM_PLUGIN_PATH = "${pkgs.qt5.qtbase.bin}/lib/qt-${pkgs.qt5.qtbase.version}/plugins";
+          };
+        };
+    };
+}