{
  description = "nova-shell - minimal Quickshell bar for niri";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";

    quickshell = {
      url = "git+https://git.outfoxxed.me/outfoxxed/quickshell";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    treefmt-nix = {
      url = "github:numtide/treefmt-nix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs =
    {
      self,
      nixpkgs,
      quickshell,
      treefmt-nix,
      ...
    }:
    let
      systems = [
        "x86_64-linux"
        "aarch64-linux"
      ];
      treefmt-config = {
        projectRootFile = "flake.nix";
        programs.nixfmt.enable = true;
        programs.qmlformat.enable = true;
        programs.rustfmt.enable = true;
        programs.taplo.enable = true;
        programs.keep-sorted.enable = true;
      };
      # Patch qtbase wayland client to fix use-after-free in QWaylandSurface::oldestEnteredScreen.
      # Waiting screens deleted via registry_global_remove leave dangling pointers in surface
      # m_screens lists, crashing on the next screensChanged signal. Track surfaces in the
      # display and scrub references before any screen deletion.
      # TODO: remove once fixed upstream in Qt
      qtbaseOverlay = final: prev: {
        qt6 = prev.qt6.overrideScope (
          qtFinal: qtPrev: {
            qtbase = qtPrev.qtbase.overrideAttrs (old: {
              patches = (old.patches or [ ]) ++ [ ./nix/patches/qtbase-wayland-screen-uaf.patch ];
            });
          }
        );
      };
      forAllSystems =
        fn:
        nixpkgs.lib.genAttrs systems (
          system:
          fn rec {
            rawPkgs = nixpkgs.legacyPackages.${system};
            pkgs = rawPkgs.extend qtbaseOverlay;
            treefmt-eval = treefmt-nix.lib.evalModule rawPkgs treefmt-config;
          }
        );
    in
    {
      formatter = forAllSystems ({ treefmt-eval, ... }: treefmt-eval.config.build.wrapper);

      packages = forAllSystems (
        { pkgs, rawPkgs, ... }:
        let
          # Rebuild quickshell against patched Qt via its overlay
          qs = (pkgs.extend quickshell.overlays.default).quickshell.override {
            withX11 = false;
            withI3 = false;
          };
          nova-stats = pkgs.callPackage ./nix/stats-daemon.nix { };
          nova-shaders = pkgs.callPackage ./nix/shaders.nix { };
        in
        rec {
          inherit nova-stats nova-shaders;
          nova-shell = pkgs.callPackage ./nix/package.nix {
            quickshell = qs;
            inherit nova-stats nova-shaders;
          };
          nova-shell-cli = pkgs.runCommand "nova-shell-cli" { nativeBuildInputs = [ pkgs.makeWrapper ]; } ''
            mkdir -p $out/bin
            makeWrapper ${qs}/bin/quickshell $out/bin/nova-shell \
              --add-flags "-p ${nova-shell}/share/nova-shell/shell.qml"
          '';
          docs = pkgs.callPackage ./nix/docs.nix { inherit self; };
          default = nova-shell;

          # nova-shell on unpatched Qt for A/B crash testing
          nova-shell-unpatched =
            let
              qsUnpatched = (rawPkgs.extend quickshell.overlays.default).quickshell.override {
                withX11 = false;
                withI3 = false;
              };
            in
            rawPkgs.callPackage ./nix/package.nix {
              quickshell = qsUnpatched;
              nova-stats = rawPkgs.callPackage ./nix/stats-daemon.nix { };
              nova-shaders = rawPkgs.callPackage ./nix/shaders.nix { };
            };
        }
      );

      devShells = forAllSystems (
        { rawPkgs, ... }:
        {
          default = rawPkgs.mkShell {
            packages = with rawPkgs; [
              cargo
              rustc
              rust-analyzer
              clippy
              rustfmt
              libnotify
              qt6.qtdeclarative
            ];
          };
        }
      );

      checks = forAllSystems (
        {
          pkgs,
          rawPkgs,
          treefmt-eval,
        }:
        {
          formatting = treefmt-eval.config.build.check self;
          build = self.packages.${pkgs.stdenv.hostPlatform.system}.default;
          nova-stats = self.packages.${pkgs.stdenv.hostPlatform.system}.nova-stats;
          docs = self.packages.${pkgs.stdenv.hostPlatform.system}.docs;
          qmllint =
            rawPkgs.runCommand "nova-shell-qmllint"
              {
                nativeBuildInputs = [ rawPkgs.qt6.qtdeclarative ];
                src = self;
              }
              ''
                cd $src
                export QML_IMPORT_PATH="${rawPkgs.qt6.qtdeclarative}/lib/qt-6/qml:${
                  quickshell.packages.${pkgs.stdenv.hostPlatform.system}.default
                }/lib/qt-6/qml"
                qmllint -E \
                  -I shell/modules -I shell/services -I shell/applets -I shell/lock \
                  shell/shell.qml shell/modules/*.qml shell/services/*.qml \
                  shell/applets/*.qml shell/lock/*.qml \
                  > $TMPDIR/raw.txt 2>&1 || true

                # Extract unique warning messages (file:message, without line numbers)
                grep -E "^Warning:" $TMPDIR/raw.txt \
                  | sed 's/^Warning: //' \
                  | sed 's/\([^:]*\):[0-9]*:[0-9]*: /\1: /' \
                  | sort -u > $TMPDIR/current.txt

                # Compare against baseline
                touch $TMPDIR/new-warnings.txt $TMPDIR/stale-warnings.txt
                while IFS= read -r line; do
                  if ! grep -qFx "$line" test/qmllint-baseline.txt 2>/dev/null; then
                    echo "$line" >> $TMPDIR/new-warnings.txt
                  fi
                done < $TMPDIR/current.txt

                while IFS= read -r line; do
                  if ! grep -qFx "$line" $TMPDIR/current.txt; then
                    echo "$line" >> $TMPDIR/stale-warnings.txt
                  fi
                done < test/qmllint-baseline.txt

                # Output dir with individual files for inspection
                mkdir -p $out
                cp $TMPDIR/raw.txt $out/raw.txt
                cp $TMPDIR/current.txt $out/current.txt
                cp test/qmllint-baseline.txt $out/baseline.txt
                cp $TMPDIR/new-warnings.txt $out/new-warnings.txt
                cp $TMPDIR/stale-warnings.txt $out/stale-warnings.txt

                failed=0
                if [ -s $TMPDIR/new-warnings.txt ]; then
                  echo "new warnings:"
                  sed 's/^/  /' $TMPDIR/new-warnings.txt
                  failed=1
                fi
                if [ -s $TMPDIR/stale-warnings.txt ]; then
                  echo "stale warnings:"
                  sed 's/^/  /' $TMPDIR/stale-warnings.txt
                  failed=1
                fi

                [ "$failed" -eq 0 ] || exit 1
              '';
          nova-stats-clippy = (pkgs.callPackage ./nix/stats-daemon.nix { }).overrideAttrs (old: {
            pname = "nova-stats-clippy";
            nativeBuildInputs = old.nativeBuildInputs ++ [ pkgs.clippy ];
            buildPhase = "cargo clippy --all-targets -- -D warnings";
            installPhase = "touch $out";
            doCheck = false;
          });
        }
      );

      homeModules.default = import ./nix/hm-module.nix self;
      homeManagerModules.default = self.homeModules.default;
    };
}