{
  description = "photogallery uploader — Qt6 C++ desktop app";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs { inherit system; };
        inherit (pkgs) lib stdenv;

        # Wayland is Linux-only; macOS uses the Cocoa QPA plugin inside qtbase,
        # so qtwayland is added only on Linux (it refuses to evaluate on darwin).
        qtModules = [ pkgs.qt6.qtbase pkgs.qt6.qtimageformats ]
          ++ lib.optionals stdenv.hostPlatform.isLinux [ pkgs.qt6.qtwayland ];

        qtPlugins = lib.makeSearchPathOutput "out" "lib/qt-6/plugins" qtModules;
      in {
        # Installable build: `nix profile install ./desktop` drops "Photog" into
        # the application menu with its icon. wrapQtAppsHook wraps the binary so
        # it finds the Qt platform (Cocoa on macOS; xcb + wayland on Linux) and
        # image-format plugins on its own, without the dev shell.
        packages.default = stdenv.mkDerivation {
          pname = "photog";
          version = "0.1.0";
          src = ./.;
          nativeBuildInputs = with pkgs; [
            cmake
            ninja
            pkg-config
            qt6.wrapQtAppsHook
          ];
          buildInputs = [ pkgs.qt6Packages.qtkeychain ] ++ qtModules;
          meta.mainProgram = "photog";
        };

        devShells.default = pkgs.mkShell {
          packages = with pkgs; [
            cmake
            ninja
            pkg-config
            qt6Packages.qtkeychain # password → Keychain (macOS) / libsecret / kwallet
          ] ++ qtModules;

          shellHook = ''
            # Let a binary run straight from the build dir find Qt's platform and
            # image-format plugins without wrapQtAppsHook.
            export QT_PLUGIN_PATH="${qtPlugins}''${QT_PLUGIN_PATH:+:$QT_PLUGIN_PATH}"
          '';
        };
      });
}