{
  lib,
  python3Packages,
  gtk4,
  gobject-introspection,
  wrapGAppsHook4,
}:

python3Packages.buildPythonApplication rec {
  pname = "shikaku";
  version = "0.1.0";
  pyproject = false;

  src = ./.;

  nativeBuildInputs = [
    gobject-introspection
    wrapGAppsHook4
  ];

  buildInputs = [
    gtk4
  ];

  dependencies = with python3Packages; [
    pygobject3
  ];

  # Pure Python — nothing to compile
  dontBuild = true;

  installPhase = ''
    runHook preInstall

    install -Dm755 shikaku.py $out/share/shikaku/shikaku.py

    # Wrapper script so wrapGAppsHook4 can inject GDK/GI env vars
    mkdir -p $out/bin
    cat > $out/bin/shikaku << EOF
    #!${python3Packages.python.interpreter}
    import sys
    sys.path.insert(0, "$out/share/shikaku")
    import shikaku
    shikaku.main()
    EOF
    chmod +x $out/bin/shikaku

    # Desktop entry for app launchers (GNOME, KDE, etc.)
    install -Dm644 /dev/stdin $out/share/applications/shikaku.desktop << EOF
    [Desktop Entry]
    Version=1.0
    Type=Application
    Name=Shikaku
    Comment=Rectangle partition logic puzzle
    Exec=shikaku
    Icon=applications-games
    Terminal=false
    Categories=Game;LogicGame;BoardGame;
    Keywords=puzzle;shikaku;logic;grid;rectangle;
    EOF

    runHook postInstall
  '';

  # wrapGAppsHook4 handles GDK_PIXBUF_MODULE_FILE, XDG_DATA_DIRS, GI_TYPELIB_PATH, etc.
  # but it expects to wrap a binary. Point it at our wrapper script.
  dontWrapGApps = false;

  passthru.tests.shikaku-starts = python3Packages.pytestCheckHook;

  meta = {
    description = "Rectangle partition logic puzzle (Shikaku)";
    longDescription = ''
      Shikaku is a logic puzzle where you partition a grid into non-overlapping
      rectangles. Each rectangle must contain exactly one number, and that number
      equals the area of the rectangle in cells. Puzzles are procedurally generated
      and guaranteed to be solvable. Supports 5×5 and 7×7 grids, with larger sizes
      planned. Built with Python and GTK4; plays fully offline.
    '';
    homepage = "https://github.com/your-github-username/shikaku"; # TODO
    # changelog = "https://github.com/your-github-username/shikaku/blob/v${version}/CHANGELOG.md";
    license = lib.licenses.mit;
    maintainers = with lib.maintainers; [
      # your-nixpkgs-handle  # TODO: add yourself to maintainers/maintainer-list.nix first
    ];
    platforms = lib.platforms.linux;
    mainProgram = "shikaku";
  };
}