claude-desktop/nix/default.nix

# Claude Desktop — Nix-Wrapper-Paket
#
# Liefert:
#   $out/bin/claude-desktop           — Launcher mit LD_LIBRARY_PATH
#   $out/bin/claude-desktop-install   — Installer (kopiert Binary nach ~/.local/share)
#   $out/share/applications/…         — Desktop-Entry
#   $out/share/icons/…                — Icon
#
# Das eigentliche Binary lebt unter ~/.local/share/claude-desktop/bin/claude-desktop
# (writable), damit der Auto-Updater es ersetzen kann. Nix-Store ist read-only und
# waere deshalb inkompatibel mit dem Rename-Trick in apply_update().
#
# Einbinden in /etc/nixos/configuration.nix:
#
#   environment.systemPackages = [
#     (import /pfad/zum/claude-desktop/nix/default.nix { inherit pkgs; })
#   ];
#
# Oder per home-manager:
#   home.packages = [ (import ./claude-desktop/nix/default.nix { inherit pkgs; }) ];

{ pkgs ? import <nixpkgs> {} }:

let
  # Alle Laufzeit-Libs, die das Tauri-Binary braucht (parallel zu shell.nix).
  runtimeLibs = with pkgs; [
    webkitgtk_4_1
    libappindicator-gtk3
    librsvg
    gtk3
    glib
    cairo
    pango
    gdk-pixbuf
    libsoup_3
    at-spi2-atk
    openssl
  ];

  # Laufzeit-Binaries die die App spawnen muss (node fuer claude-bridge.js,
  # npm fuer apply_bundle_update, tar fuer Bundle-Extract)
  runtimeBins = [ pkgs.nodejs_22 pkgs.gnutar pkgs.gzip ];
in
pkgs.stdenv.mkDerivation {
  pname = "claude-desktop";
  version = "0.1.0";
  # Keine Quelldateien — Wir packen nur Wrapper + Desktop-Entry
  dontUnpack = true;

  nativeBuildInputs = [ pkgs.makeWrapper ];

  installPhase = ''
    runHook preInstall

    mkdir -p $out/bin $out/share/applications $out/share/icons/hicolor/256x256/apps

    # 1) Launcher: startet das User-Binary mit Nix-LD_LIBRARY_PATH
    cat > $out/bin/claude-desktop <<'LAUNCHER'
    #!${pkgs.bash}/bin/bash
    # Claude Desktop — NixOS-Launcher
    set -e

    APP_DIR="$HOME/.local/share/claude-desktop"
    BIN="$APP_DIR/bin/claude-desktop"

    if [ ! -x "$BIN" ]; then
      echo "⚠️  Claude-Desktop-Binary nicht gefunden: $BIN" >&2
      echo "" >&2
      echo "Erst installieren (aus fertigem Build in /tmp/claude-target):" >&2
      echo "  claude-desktop-install" >&2
      echo "" >&2
      echo "Oder neu bauen im Repo:" >&2
      echo "  CARGO_TARGET_DIR=/tmp/claude-target \\" >&2
      echo "    nix-shell shell.nix --run 'npm ci && npm run tauri build'" >&2
      echo "  claude-desktop-install" >&2
      exit 1
    fi

    # Marker fuer update.rs: wir laufen unter Nix-Wrapper
    export CLAUDE_DESKTOP_NIX_WRAPPER=1
    export CLAUDE_DESKTOP_BIN="$BIN"

    # HiDPI/Fractional-Scaling — GTK3 unter Wayland kann kein natives fractional
    # scaling. Workaround: Xwayland erzwingen (der Compositor skaliert das Fenster)
    # und GDK_DPI_SCALE aus Xft.dpi ableiten, damit Fonts scharf bleiben.
    # Override-bar ueber CLAUDE_DESKTOP_SCALE (z.B. "1.5") oder komplett
    # deaktivierbar mit CLAUDE_DESKTOP_SCALE=off.
    if [ "''${CLAUDE_DESKTOP_SCALE:-}" != "off" ]; then
      SCALE="''${CLAUDE_DESKTOP_SCALE:-}"
      if [ -z "$SCALE" ] && command -v xrdb >/dev/null 2>&1 && [ -n "''${DISPLAY:-}" ]; then
        DPI="$(xrdb -query 2>/dev/null | awk -F':\\s*' '/^Xft.dpi:/ {print $2; exit}')"
        if [ -n "$DPI" ] && [ "$DPI" -gt 96 ] 2>/dev/null; then
          # bash-only float-Division: auf 2 Stellen runden
          SCALE="$(awk -v d="$DPI" 'BEGIN { printf "%.2f", d/96 }')"
        fi
      fi
      if [ -n "$SCALE" ] && [ "$SCALE" != "1.00" ] && [ "$SCALE" != "1.0" ]; then
        export GDK_DPI_SCALE="$SCALE"
        # Unter Wayland: Xwayland nutzen, damit der Compositor-Scale greift
        if [ "''${XDG_SESSION_TYPE:-}" = "wayland" ]; then
          export GDK_BACKEND="''${GDK_BACKEND:-x11}"
        fi
      fi
    fi

    exec "$BIN" "$@"
    LAUNCHER
    chmod +x $out/bin/claude-desktop

    # LD_LIBRARY_PATH + PATH dauerhaft ans Launcher-Script binden
    # PATH: node/npm/tar muessen fuer die Bridge und apply_bundle_update verfuegbar sein
    wrapProgram $out/bin/claude-desktop \
      --prefix LD_LIBRARY_PATH : ${pkgs.lib.makeLibraryPath runtimeLibs} \
      --prefix PATH : ${pkgs.lib.makeBinPath runtimeBins}

    # 2) Installer: kopiert ein frisch gebautes Binary an den Ziel-Ort
    cat > $out/bin/claude-desktop-install <<'INSTALLER'
    #!${pkgs.bash}/bin/bash
    set -e
    SRC="''${1:-/tmp/claude-target/release/claude-desktop}"
    DEST_DIR="$HOME/.local/share/claude-desktop/bin"
    DEST="$DEST_DIR/claude-desktop"

    if [ ! -x "$SRC" ]; then
      echo "❌ Quelle nicht gefunden oder nicht ausfuehrbar: $SRC" >&2
      echo "" >&2
      echo "Erst bauen:" >&2
      echo "  cd <repo>; CARGO_TARGET_DIR=/tmp/claude-target \\" >&2
      echo "    nix-shell shell.nix --run 'npm ci && npm run tauri build'" >&2
      exit 1
    fi

    mkdir -p "$DEST_DIR"
    cp "$SRC" "$DEST"
    chmod +x "$DEST"

    echo "✅ Claude Desktop installiert nach $DEST"
    echo "   Starten mit: claude-desktop  (oder aus KDE-Menue)"
    INSTALLER
    chmod +x $out/bin/claude-desktop-install

    # 3) Desktop-Entry
    cp ${./claude-desktop.desktop} $out/share/applications/claude-desktop.desktop

    # 4) Icon
    cp ${../src-tauri/icons/icon.png} $out/share/icons/hicolor/256x256/apps/claude-desktop.png

    runHook postInstall
  '';

  meta = with pkgs.lib; {
    description = "Native Desktop-App fuer Claude Code (Wrapper-Paket, Binary in ~/.local/share)";
    homepage = "https://git.data-it-solution.de/data/claude-desktop";
    license = licenses.mit;
    platforms = platforms.linux;
    mainProgram = "claude-desktop";
  };
}