{ lib
, stdenv
, substituteAll
, fetchurl
, pkg-config
, gettext
, graphene
, gi-docgen
, meson
, ninja
, python3
, makeWrapper
, shared-mime-info
, isocodes
, glib
, cairo
, pango
, pandoc
, gdk-pixbuf
, gobject-introspection
, fribidi
, xorg
, epoxy
, json-glib
, libxkbcommon
, libxml2
, librest
, libsoup
, ffmpeg
, gmp
, gnome3
, gsettings-desktop-schemas
, gst_all_1
, sassc
, trackerSupport ? stdenv.isLinux
, tracker
, x11Support ? stdenv.isLinux
, waylandSupport ? stdenv.isLinux
, libGL
, vulkan-loader
, vulkan-headers
, wayland
, wayland-protocols
, xineramaSupport ? stdenv.isLinux
, cupsSupport ? stdenv.isLinux
, cups
, AppKit
, Cocoa
, broadwaySupport ? true
}:

let

  gtkCleanImmodulesCache = substituteAll {
    src = ./hooks/clean-immodules-cache.sh;
    gtk_module_path = "gtk-4.0";
    gtk_binary_version = "4.0.0";
  };

in

stdenv.mkDerivation rec {
  pname = "gtk4";
  version = "4.2.1";

  outputs = [ "out" "dev" ] ++ lib.optionals x11Support [ "devdoc" ];
  outputBin = "dev";

  setupHooks = [
    ./hooks/drop-icon-theme-cache.sh
    gtkCleanImmodulesCache
  ];

  src = fetchurl {
    url = "mirror://gnome/sources/gtk/${lib.versions.majorMinor version}/gtk-${version}.tar.xz";
    sha256 = "AjFpd13kPwof3gZvvBnXhUXqanViwZFavem4rkpzCeY=";
  };

  nativeBuildInputs = [
    gettext
    gobject-introspection
    makeWrapper
    meson
    ninja
    pkg-config
    python3
    sassc
    gi-docgen
  ] ++ setupHooks;

  buildInputs = [
    libxkbcommon
    epoxy
    json-glib
    isocodes
  ] ++ lib.optionals (!stdenv.isDarwin) [
    vulkan-headers
  ] ++ [
    librest
    libsoup
    ffmpeg
    gst_all_1.gst-plugins-base
    gst_all_1.gst-plugins-bad
    fribidi
  ] ++ (with xorg; [
    libICE
    libSM
    libXcomposite
    libXcursor
    libXi
    libXrandr
    libXrender
  ]) ++ lib.optionals stdenv.isDarwin [
    AppKit
  ] ++ lib.optionals trackerSupport [
    tracker
  ] ++ lib.optionals waylandSupport [
    libGL
    wayland
    wayland-protocols
  ] ++ lib.optionals xineramaSupport [
    xorg.libXinerama
  ] ++ lib.optionals cupsSupport [
    cups
  ] ++ lib.optionals stdenv.isDarwin [
    Cocoa
  ];
  #TODO: colord?

  propagatedBuildInputs = [
    # Required by pkg-config files.
    cairo
    gdk-pixbuf
    glib
    graphene
    pango
  ] ++ lib.optionals (!stdenv.isDarwin) [
    vulkan-loader
  ] ++ [
    # Required for GSettings schemas at runtime.
    # Will be picked up by wrapGAppsHook.
    gsettings-desktop-schemas
  ];

  mesonFlags = [
    # ../docs/tools/shooter.c:4:10: fatal error: 'cairo-xlib.h' file not found
    "-Dgtk_doc=${lib.boolToString x11Support}"
    "-Dbuild-tests=false"
    "-Dtracker=${if trackerSupport then "enabled" else "disabled"}"
    "-Dbroadway-backend=${lib.boolToString broadwaySupport}"
  ] ++ lib.optionals (!cupsSupport) [
    "-Dprint-cups=disabled"
  ] ++ lib.optionals stdenv.isDarwin [
    "-Dvulkan=disabled"
    "-Dmedia-gstreamer=disabled" # requires gstreamer-gl
  ] ++ lib.optionals (!x11Support) [
    "-Dx11-backend=false"
  ];

  doCheck = false; # needs X11

  separateDebugInfo = stdenv.isLinux;

  # These are the defines that'd you'd get with --enable-debug=minimum (default).
  # See: https://developer.gnome.org/gtk3/stable/gtk-building.html#extra-configuration-options
  NIX_CFLAGS_COMPILE = "-DG_ENABLE_DEBUG -DG_DISABLE_CAST_CHECKS";

  postPatch = ''
    files=(
      build-aux/meson/post-install.py
      demos/gtk-demo/geninclude.py
      gdk/broadway/gen-c-array.py
      gdk/gen-gdk-gresources-xml.py
      gtk/gen-gtk-gresources-xml.py
      gtk/gentypefuncs.py
    )

    chmod +x ''${files[@]}
    patchShebangs ''${files[@]}
  '';

  preInstall = ''
    OLD_PATH="$PATH"
    PATH="$PATH:$dev/bin" # so the install script finds gtk4-update-icon-cache
  '';

  postInstall = ''
    PATH="$OLD_PATH"
  '' + lib.optionalString (!stdenv.isDarwin) ''
    # The updater is needed for nixos env and it's tiny.
    moveToOutput bin/gtk4-update-icon-cache "$out"
    # Launcher
    moveToOutput bin/gtk-launch "$out"

    # TODO: patch glib directly
    for f in $dev/bin/gtk4-encode-symbolic-svg; do
      wrapProgram $f --prefix XDG_DATA_DIRS : "${shared-mime-info}/share"
    done

  '' + lib.optionalString x11Support ''
    # So that DevHelp can find this.
    # TODO: Remove this with DevHelp 41.
    mkdir -p "$devdoc/share/devhelp/books"
    mv "$out/share/doc/"* "$devdoc/share/devhelp/books"
    rmdir -p --ignore-fail-on-non-empty "$out/share/doc"
  '';

  # Wrap demos
  postFixup =  lib.optionalString (!stdenv.isDarwin) ''
    demos=(gtk4-demo gtk4-demo-application gtk4-icon-browser gtk4-widget-factory)

    for program in ''${demos[@]}; do
      wrapProgram $dev/bin/$program \
        --prefix XDG_DATA_DIRS : "$GSETTINGS_SCHEMAS_PATH:$out/share/gsettings-schemas/${pname}-${version}"
    done
  '';

  passthru = {
    updateScript = gnome3.updateScript {
      packageName = "gtk";
      attrPath = "gtk4";
    };
  };

  meta = with lib; {
    description = "A multi-platform toolkit for creating graphical user interfaces";
    longDescription = ''
      GTK is a highly usable, feature rich toolkit for creating
      graphical user interfaces which boasts cross platform
      compatibility and an easy to use API.  GTK it is written in C,
      but has bindings to many other popular programming languages
      such as C++, Python and C# among others.  GTK is licensed
      under the GNU LGPL 2.1 allowing development of both free and
      proprietary software with GTK without any license fees or
      royalties.
    '';
    homepage = "https://www.gtk.org/";
    license = licenses.lgpl2Plus;
    maintainers = with maintainers; [ raskin lethalman worldofpeace ];
    platforms = platforms.all;
    changelog = "https://gitlab.gnome.org/GNOME/gtk/-/raw/${version}/NEWS";
  };
}