nixos-config/hosts/aarch64-linux/alastor/apple-silicon-support/modules/sound/default.nix

{
  config,
  options,
  pkgs,
  lib,
  ...
}: {
  imports = [
    # disable pulseaudio as the Asahi sound infrastructure can't use it.
    # if we disable it only if setupAsahiSound is enabled, then infinite
    # recursion results as pulseaudio enables config.sound by default.
    {config.hardware.pulseaudio.enable = !config.hardware.asahi.enable;}
  ];

  options.hardware.asahi = {
    setupAsahiSound = lib.mkOption {
      type = lib.types.bool;
      default = config.sound.enable && config.hardware.asahi.enable;
      description = ''
        Set up the Asahi DSP components so that the speakers and headphone jack
        work properly and safely.
      '';
    };
  };

  config = let
    cfg = config.hardware.asahi;

    asahi-audio = pkgs.asahi-audio; # the asahi-audio we use

    lsp-plugins = pkgs.lsp-plugins; # the lsp-plugins we use

    lsp-plugins-is-patched =
      (lsp-plugins.overrideAttrs (old: {
        passthru =
          (old.passthru or {})
          // {
            lsp-plugins-is-patched =
              builtins.elem "58c3f985f009c84347fa91236f164a9e47aafa93.patch"
              (builtins.map (p: p.name) (old.patches or []));
          };
      }))
      .lsp-plugins-is-patched;

    lsp-plugins-is-safe = (pkgs.lib.versionAtLeast lsp-plugins.version "1.2.14") || lsp-plugins-is-patched;

    # https://github.com/NixOS/nixpkgs/pull/282377
    # options is the set of all module option declarations, rather than their
    # values, to prevent infinite recursion
    newHotness = builtins.hasAttr "configPackages" options.services.pipewire;

    lv2Path = lib.makeSearchPath "lib/lv2" [lsp-plugins pkgs.bankstown-lv2];
  in
    lib.mkIf (cfg.setupAsahiSound && cfg.enable) (lib.mkMerge [
      {
        # enable pipewire to run real-time and avoid audible glitches
        security.rtkit.enable = true;
        # set up pipewire with the supported capabilities (instead of pulseaudio)
        # and asahi-audio configs and plugins
        services.pipewire = {
          enable = true;

          alsa.enable = true;
          pulse.enable = true;
          wireplumber.enable = true;
        };

        # set up enivronment so that UCM configs are used as well
        environment.variables.ALSA_CONFIG_UCM2 = "${pkgs.alsa-ucm-conf-asahi}/share/alsa/ucm2";
        systemd.user.services.pipewire.environment.ALSA_CONFIG_UCM2 = config.environment.variables.ALSA_CONFIG_UCM2;
        systemd.user.services.wireplumber.environment.ALSA_CONFIG_UCM2 = config.environment.variables.ALSA_CONFIG_UCM2;

        # enable speakersafetyd to protect speakers
        systemd.packages =
          lib.mkAssert lsp-plugins-is-safe
          "lsp-plugins is unpatched/outdated and speakers cannot be safely enabled"
          [pkgs.speakersafetyd];
        services.udev.packages = [pkgs.speakersafetyd];
      }
      (lib.optionalAttrs newHotness {
        # use configPackages and friends to install asahi-audio and plugins
        services.pipewire = {
          configPackages = [asahi-audio];
          extraLv2Packages = [lsp-plugins pkgs.bankstown-lv2];
          wireplumber = {
            configPackages = [asahi-audio];
            extraLv2Packages = [lsp-plugins pkgs.bankstown-lv2];
          };
        };
      })
      (lib.optionalAttrs (!newHotness) {
        # use environment.etc and environment variables to install asahi-audio and plugins
        environment.etc = builtins.listToAttrs (builtins.map
          (f: {
            name = f;
            value = {source = "${asahi-audio}/share/${f}";};
          })
          asahi-audio.providedConfigFiles);

        systemd.user.services.pipewire.environment.LV2_PATH = lv2Path;
        systemd.user.services.wireplumber.environment.LV2_PATH = lv2Path;
      })
    ]);
}