{
  stdenv,
  lib,
  buildFHSEnv,
  copyDesktopItems,
  fetchurl,
  gsettings-desktop-schemas,
  makeDesktopItem,
  makeWrapper,
  opensc,
  writeTextDir,
  writeShellScript,
  # New dependencies for aarch64 support
  fex,
  muvm,
  configText ? "",
  # Allow users to choose emulation method
  useMusvm ? true, # Use muvm + FEX (better isolation) vs just FEX
}:
let
  version = "2506";

  isAarch64 = stdenv.hostPlatform.system == "aarch64-linux";

  # Always extract x64 binaries (we'll emulate on aarch64)
  sysArch = "x64";

  # For USB support, ensure that /var/run/omnissa/<YOUR-UID>
  # exists and is owned by you. Then run omnissa-usbarbitrator as root.

  mainProgram = "horizon-client";

  # This forces the default GTK theme (Adwaita) because Horizon is prone to
  # UI usability issues when using non-default themes, such as Adwaita-dark.
  wrapBinCommands = path: name: ''
    makeWrapper "$out/${path}/${name}" "$out/bin/${name}_wrapper" \
    --set GTK_THEME Adwaita \
    --suffix XDG_DATA_DIRS : "${gsettings-desktop-schemas}/share/gsettings-schemas/${gsettings-desktop-schemas.name}" \
    --suffix LD_LIBRARY_PATH : "$out/lib/omnissa/horizon/crtbora:$out/lib/omnissa"
  '';

  omnissaHorizonClientFiles = stdenv.mkDerivation {
    pname = "omnissa-horizon-files";
    inherit version;
    src = fetchurl {
      url = "https://download3.omnissa.com/software/CART26FQ2_LIN_2506_TARBALL/Omnissa-Horizon-Client-Linux-2506-8.16.0-16536624989.tar.gz";
      sha256 = "5515e79188e2605ced5a95c3a3829865b567be5d7a8de00a57455f7b5b2ae392";
    };
    nativeBuildInputs = [ makeWrapper ];
    installPhase = ''
      mkdir ext
      find ${sysArch} -type f -print0 | xargs -0n1 tar -Cext --strip-components=1 -xf

      chmod -R u+w ext/usr/lib
      mv ext/usr $out
      cp -r ext/${sysArch}/include $out/
      cp -r ext/${sysArch}/lib $out/

      # Horizon includes a copy of libstdc++ which is loaded via $LD_LIBRARY_PATH
      # when it cannot detect a new enough version already present on the system.
      # The checks are distribution-specific and do not function correctly on NixOS.
      # Deleting the bundled library is the simplest way to force it to use our version.
      rm "$out/lib/omnissa/gcc/libstdc++.so.6"

      # This opensc library is required to support smartcard authentication during the
      # initial connection to Horizon.
      mkdir $out/lib/omnissa/horizon/pkcs11
      ln -s ${opensc}/lib/pkcs11/opensc-pkcs11.so $out/lib/omnissa/horizon/pkcs11/libopenscpkcs11.so

      ${wrapBinCommands "bin" "horizon-client"}
      ${wrapBinCommands "lib/omnissa/horizon/usb" "horizon-eucusbarbitrator"}
    '';
  };

  # x86_64 FHS environment for native or emulated execution
  omnissaFHSUserEnv =
    pname:
    buildFHSEnv {
      inherit pname version;

      # On aarch64, we need to invoke via FEX or muvm
      runScript = "${omnissaHorizonClientFiles}/bin/${pname}_wrapper";

      targetPkgs =
        pkgs: with pkgs; [
          at-spi2-atk
          atk
          cairo
          dbus
          file
          fontconfig
          freetype
          gdk-pixbuf
          glib
          gtk2
          gtk3-x11
          harfbuzz
          liberation_ttf
          libjpeg
          libpng
          libpulseaudio
          libtiff
          libudev0-shim
          libuuid
          libv4l
          pango
          pcsclite
          pixman
          udev
          omnissaHorizonClientFiles
          xorg.libX11
          xorg.libXau
          xorg.libXcursor
          xorg.libXext
          xorg.libXi
          xorg.libXinerama
          xorg.libxkbfile
          xorg.libXrandr
          xorg.libXrender
          xorg.libXScrnSaver
          xorg.libXtst
          zlib
          libxml2_13

          (writeTextDir "etc/omnissa/config" configText)
        ];
    };

  # Create wrapper scripts for aarch64 that use FEX or muvm
  # Option 1: Direct FEX execution (simpler, less isolation)
  fexWrapper =
    pname:
    writeShellScript "${pname}-fex-wrapper" ''
      export FEXINTERPRETER="${fex}/bin/FEXInterpreter"
      export FEX_ROOTFS="${fex}/share/fex-emu/RootFS"

      # Set up FEX environment
      export FEX_TSOENABLED=1

      exec ${fex}/bin/FEXBash -c '${omnissaFHSUserEnv pname}/bin/${pname} "$@"' -- "$@"
    '';

  # Option 2: muvm + FEX (better isolation, handles kernel differences)
  muvmWrapper =
    pname:
    writeShellScript "${pname}-muvm-wrapper" ''
      # muvm creates a lightweight VM with x86_64 emulation via FEX
      # This provides better isolation and compatibility

      exec ${muvm}/bin/muvm \
        --fex \
        --share-display \
        --share-sound \
        -- ${omnissaFHSUserEnv pname}/bin/${pname} "$@"
    '';

  # Select the appropriate wrapper based on configuration
  aarch64Wrapper = pname: if useMusvm then muvmWrapper pname else fexWrapper pname;

  # Final wrapper that handles both architectures

  desktopItem = makeDesktopItem {
    name = "horizon-client";
    desktopName = "Omnissa Horizon Client";
    icon = "${omnissaHorizonClientFiles}/share/icons/horizon-client.png";
    exec = "${
      if isAarch64 then
        aarch64Wrapper mainProgram
      else
        "${omnissaFHSUserEnv mainProgram}/bin/${mainProgram}"
    } %u";
    mimeTypes = [
      "x-scheme-handler/horizon-client"
      "x-scheme-handler/vmware-view"
    ];
  };

in
stdenv.mkDerivation {
  pname = "omnissa-horizon-client";
  inherit version;

  dontUnpack = true;

  nativeBuildInputs = [ copyDesktopItems ];

  desktopItems = [ desktopItem ];

  installPhase = ''
    runHook preInstall
    mkdir -p $out/bin

    ${
      if isAarch64 then
        ''
          # On aarch64, create wrapper scripts that use FEX/muvm
          cp ${aarch64Wrapper "horizon-client"} $out/bin/horizon-client
          chmod +x $out/bin/horizon-client
          cp ${aarch64Wrapper "omnissa-usbarbitrator"} $out/bin/omnissa-usbarbitrator
          chmod +x $out/bin/omnissa-usbarbitrator
        ''
      else
        ''
          # On x86_64, use native FHS environment directly
          ln -s ${omnissaFHSUserEnv "horizon-client"}/bin/horizon-client $out/bin/
          ln -s ${omnissaFHSUserEnv "omnissa-usbarbitrator"}/bin/omnissa-usbarbitrator $out/bin/
        ''
    }

    runHook postInstall
  '';

  unwrapped = omnissaHorizonClientFiles;

  passthru = {
    updateScript = ./update.sh;
    # Expose FHS env for debugging
    fhsEnv = omnissaFHSUserEnv mainProgram;
  };

  meta = with lib; {
    inherit mainProgram;
    description = "Allows you to connect to your Omnissa Horizon virtual desktop";
    homepage = "https://www.omnissa.com/products/horizon-8/";
    license = licenses.unfree;
    platforms = [
      "x86_64-linux"
      "aarch64-linux"
    ];
    maintainers = with maintainers; [ mhutter ];
  };
}