headroom

{

  description = "automatic loudness and per-app volume control (pipewire)";

  inputs = {

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

  };

  outputs =

    {

      self,

      nixpkgs,

    }:

    let

      systems = [

        "x86_64-linux"

        "aarch64-linux"

      ];

      forAllSystems = nixpkgs.lib.genAttrs systems;

      pkgsFor =

        system:

        import nixpkgs {

          inherit system;

        };

      perSystem =

        system:

        let

          pkgs = pkgsFor system;

          # native libs the audio crates link against

          nativeAudioBuildInputs = with pkgs; [

            pipewire

            pipewire.dev

          ];

          nativeBuildTools = with pkgs; [

            pkg-config

            clang

          ];

          # system libs iced (wgpu/winit/cosmic-text) compiles + dlopens at runtime.

          # wayland-only (x11 feature off); re-add libx11/libxcursor/libxi/libxrandr/libxcb if x11 re-enabled

          guiLibs = with pkgs; [

            vulkan-loader

            libxkbcommon

            wayland

            libGL

            fontconfig

          ];

          commonEnv = {

            LIBCLANG_PATH = "${pkgs.libclang.lib}/lib";

            PKG_CONFIG_PATH = "${pkgs.pipewire.dev}/lib/pkgconfig";

          };

        in

        {

          # nix develop — dev environment

          devShell = pkgs.mkShell (

            {

              name = "headroom-dev";

              nativeBuildInputs = nativeBuildTools ++ [

                pkgs.cargo

                pkgs.clippy

                pkgs.rust-analyzer

                pkgs.rustc

                pkgs.rustfmt

              ];

              buildInputs =

                nativeAudioBuildInputs

                ++ guiLibs

                ++ (with pkgs; [

                  socat # poke the ipc socket

                  jq # pretty-print json

                  pipewire # pw-cli, pw-cat, etc.

                  wireplumber

                ]);

              shellHook = ''

                echo "headroom dev shell — rustc $(rustc --version | cut -d' ' -f2)"

                echo "  cargo build / cargo test for iteration."

                echo "  nix build  .#headroom  for the packaged binary."

                echo "  cargo run -p headroom-gui  for the GUI (needs a display)."

                export RUST_BACKTRACE=1

                export RUST_LOG=headroom=debug,info

                # iced/wgpu dlopen vulkan/wayland/xkbcommon at runtime

                export LD_LIBRARY_PATH="${pkgs.lib.makeLibraryPath guiLibs}''${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}"

              '';

            }

            // commonEnv

          );

          # nix build — packaged daemon + cli

          headroom = pkgs.rustPlatform.buildRustPackage (

            {

              pname = "headroom";

              # workspace version (per-crate manifests use version.workspace = true)

              version =

                (builtins.fromTOML (builtins.readFile ./Cargo.toml)).workspace.package.version

                + "-"

                + (toString self.lastModifiedDate);

              src = ./.;

              cargoLock = {

                lockFile = ./Cargo.lock;

                # allowBuiltinFetchGit = true;

              };

              nativeBuildInputs = nativeBuildTools;

              buildInputs = nativeAudioBuildInputs;

              # one binary: `headroom` (cli + daemon)

              cargoBuildFlags = [

                "-p"

                "headroom-cli"

              ];

              doCheck = true;

              # exclude headroom-gui from the test sweep — pulls iced's gpu stack, not part of the daemon

              cargoTestFlags = [

                "--workspace"

                "--exclude"

                "headroom-gui"

              ];

              # systemd user unit (@bindir@ templated to this derivation's bin, not PATH)

              # + canonical profiles under share/headroom/profiles (daemon finds via $XDG_DATA_DIRS)

              postInstall = ''

                install -Dm644 contrib/systemd/headroom.service \

                  "$out/lib/systemd/user/headroom.service"

                substituteInPlace "$out/lib/systemd/user/headroom.service" \

                  --replace-fail '@bindir@' "$out/bin"

                mkdir -p "$out/share/headroom/profiles"

                cp -r profiles/. "$out/share/headroom/profiles/"

              '';

              meta = with pkgs.lib; {

                description = "automatic loudness and per-app volume control (pipewire)";

                license = licenses.gpl3Plus;

                platforms = platforms.linux;

                mainProgram = "headroom";

              };

            }

            // commonEnv

          );

          # `nix build .#headroom-gui` — optional iced GUI monitor.

          # separate package so the default build stays graphics-free. iced/wgpu

          # dlopen vulkan/libGL/wayland/xkbcommon at runtime → wrap with LD_LIBRARY_PATH.

          # also ships the .desktop entry.

          headroom-gui = pkgs.rustPlatform.buildRustPackage (

            {

              pname = "headroom-gui";

              version =

                (builtins.fromTOML (builtins.readFile ./Cargo.toml)).workspace.package.version

                + "-"

                + (toString self.lastModifiedDate);

              src = ./.;

              cargoLock = {

                lockFile = ./Cargo.lock;

              };

              # makeWrapper for the LD_LIBRARY_PATH wrap. gui doesn't link pipewire

              # (talks to the daemon over the socket via headroom-client) → no pipewire/clang

              nativeBuildInputs = [

                pkgs.pkg-config

                pkgs.makeWrapper

              ];

              buildInputs = guiLibs;

              cargoBuildFlags = [

                "-p"

                "headroom-gui"

              ];

              # gui tests drive iced view/update; no display in the sandbox.

              # run them via `cargo test -p headroom-gui` in the dev shell instead

              doCheck = false;

              postInstall = ''

                install -Dm644 contrib/desktop/headroom-gui.desktop \

                  "$out/share/applications/headroom-gui.desktop"

                substituteInPlace "$out/share/applications/headroom-gui.desktop" \

                  --replace-fail '@bindir@' "$out/bin"

              '';

              postFixup = ''

                wrapProgram "$out/bin/headroom-gui" \

                  --prefix LD_LIBRARY_PATH : "${pkgs.lib.makeLibraryPath guiLibs}"

              '';

              meta = with pkgs.lib; {

                description = "automatic loudness and per-app volume control (pipewire)";

                license = licenses.eupl12;

                platforms = platforms.linux;

                mainProgram = "headroom-gui";

              };

            }

            // commonEnv

          );

        };

    in

    {

      devShells = forAllSystems (system: {

        default = (perSystem system).devShell;

      });

      packages = forAllSystems (

        system:

        let

          ps = perSystem system;

        in

        rec {

          default = headroom;

          headroom = ps.headroom;

          headroom-gui = ps.headroom-gui;

        }

      );

      formatter = forAllSystems (system: (pkgsFor system).nixpkgs-fmt);

      # System-independent outputs — modules.

      nixosModules.default = import ./nix/nixos-module.nix self;

    };

}