nixos-config/hosts/vm-audio/configuration.nix

{
  lib,
  pkgs,
  config,
  ...
}:

{
  # State version
  system.stateVersion = "24.11";

  # Machine hostname
  networking.hostName = "vm-audio";

  # Enabled modules
  modules = {
    profiles.vm.enable = true;
    sound.enable = true;
    # spotifyd.enable = true; # TODO: Add this as a local module
  };

  # Install system packages
  environment.systemPackages = with pkgs; [
    carla
    xpra
    alsa-utils
    pulsemixer
    adwaita-icon-theme
    open-stage-control
    carla_osc_bridge

    # Add LV2 plugins
    lsp-plugins
    airwindows-lv2
    distrho-ports
    cardinal
    calf
  ];

  # Setup firewall
  networking.firewall = {
    allowedTCPPorts = [
      8080
      10402
      15151
      22752
    ];
    allowedUDPPorts = [
      8080
      10402
      15151
      22752
    ];
  };

  # Setup dependencies
  environment.variables.LD_LIBRARY_PATH = lib.mkForce "${lib.makeLibraryPath (
    with pkgs;
    [
      cairo
      pipewire.jack
    ]
  )}";
  qt = {
    enable = true;
    style = "adwaita";
  };
  xdg.icons = {
    enable = true;
    fallbackCursorThemes = [ "Adwaita" ];
  };
  hardware.graphics.enable = true;

  # User for audio mixing
  users.users.mixer = {
    isNormalUser = true;
    group = "mixer";
    extraGroups = [ "systemd-journal" ];
    openssh.authorizedKeys.keys = [
      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKKxoQSxfYqf9ITN8Fhckk8WbY4dwtBAXOhC9jxihJvq jan@bulthuis.dev"
    ];
  };
  users.groups.mixer = { };
  users.groups.audio = {
    members = [
      "mixer"
    ];
  };
  users.groups.bluetooth = {
    members = [
      "mixer"
    ];
  };

  # Xpra service
  systemd.user.services.xpra = {
    description = "Xpra Service";
    wantedBy = [ "default.target" ];
    after = [
      "network.target"
    ];
    unitConfig = {
      ConditionUser = "mixer";
    };
    serviceConfig = {
      ExecStart = "${pkgs.xpra}/bin/xpra start :7 --bind-tcp=0.0.0.0:15151 --daemon=no";
      Restart = "always";
      RestartSec = 5;
    };
  };

  # Carla service
  systemd.user.services.carla = {
    description = "Carla Service";
    wantedBy = [ "default.target" ];
    after = [
      "network.target"
      "sound.target"
    ];
    requires = [
      "xpra.service"
    ];
    unitConfig = {
      ConditionUser = "mixer";
    };
    serviceConfig = {
      ExecStart = "${pkgs.carla}/bin/carla /home/mixer/Default.carxp -platform xcb";
      Environment = "\"DISPLAY=:7\"";
      Restart = "always";
      RestartSec = 5;
    };
  };

  # Carla service
  systemd.user.services.carla-bridge = {
    description = "Carla OSC Bridge";
    wantedBy = [ "default.target" ];
    after = [
      "network.target"
      "sound.target"
    ];
    requires = [
      "carla.service"
    ];
    unitConfig = {
      ConditionUser = "mixer";
    };
    serviceConfig = {
      ExecStart = "${pkgs.carla_osc_bridge}/bin/carla_osc_bridge --clients \"127.0.0.1:8080\"";
      Restart = "always";
      RestartSec = 5;
    };
  };

  # Open stage control service
  systemd.user.services.osc = {
    description = "OSC Service";
    wantedBy = [ "default.target" ];
    after = [
      "network.target"
    ];
    requires = [
      "carla.service"
    ];
    unitConfig = {
      ConditionUser = "mixer";
    };
    serviceConfig = {
      ExecStart = "${pkgs.open-stage-control}/bin/open-stage-control --no-gui --send 127.0.0.1:10402 --load /home/mixer/open-stage-control/session.json --theme /home/mixer/open-stage-control/theme.css";
      Environment = "\"ELECTRON_RUN_AS_NODE=1\"";
      Restart = "always";
      RestartSec = 5;
    };
  };

  # Create bluetooth A2DP source
  hardware.bluetooth = {
    enable = true;
    disabledPlugins = [ "hostname" ];
    settings.General = {
      Name = "Linox";
      Class = "0x240414";
      DiscoverableTimeout = 0;
      AlwaysPairable = true;
      PairableTimeout = 0;
      FastConnectable = true;
      JustWorksRepairing = "always";
    };
  };
  services.pipewire.wireplumber.extraConfig."50-bluetooth-a2dp" = {
    "monitor.bluez.properties" = {
      "bluez5.roles" = [ "a2dp_source" ];
    };
  };

  # Create null sinks
  services.pipewire.extraConfig.pipewire."91-null-sinks" = {
    "context.objects" = [
      {
        factory = "adapter";
        args = {
          "factory.name" = "support.null-audio-sink";
          "node.name" = "Speaker-Proxy";
          "node.description" = "Proxy for Speaker Output";
          "media.class" = "Audio/Sink";
          "audio.position" = "L,R";
        };
      }
      {
        factory = "adapter";
        args = {
          "factory.name" = "support.null-audio-sink";
          "node.name" = "Headphone-Proxy";
          "node.description" = "Proxy for Headphone Output";
          "media.class" = "Audio/Sink";
          "audio.position" = "L,R";
        };
      }
      {
        factory = "adapter";
        args = {
          "factory.name" = "support.null-audio-sink";
          "node.name" = "SpotifyD-Proxy";
          "node.description" = "Proxy for SpotifyD";
          "media.class" = "Audio/Sink";
          "audio.position" = "L,R";
        };
      }
      {
        factory = "adapter";
        args = {
          "factory.name" = "support.null-audio-sink";
          "node.name" = "AnalogIn-Proxy";
          "node.description" = "Proxy for the analog input";
          "media.class" = "Audio/Source/Virtual";
          "audio.position" = "L,R";
        };
      }
    ];
  };
}