nixpkgs/nixos/modules/services/audio/squeezelite.nix

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

let
  inherit (lib) mkEnableOption mkIf mkOption optionalString types;

  dataDir = "/var/lib/squeezelite";
  cfg = config.services.squeezelite;
  pkg = if cfg.pulseAudio then pkgs.squeezelite-pulse else pkgs.squeezelite;
  bin = "${pkg}/bin/${pkg.pname}";

in
{

  ###### interface

  options.services.squeezelite = {
    enable = mkEnableOption "Squeezelite, a software Squeezebox emulator";

    pulseAudio = mkEnableOption "pulseaudio support";

    extraArguments = mkOption {
      default = "";
      type = types.str;
      description = ''
        Additional command line arguments to pass to Squeezelite.
      '';
    };
  };


  ###### implementation

  config = mkIf cfg.enable {
    systemd.services.squeezelite = {
      wantedBy = [ "multi-user.target" ];
      after = [ "network.target" "sound.target" ];
      description = "Software Squeezebox emulator";
      serviceConfig = {
        DynamicUser = true;
        ExecStart = "${bin} -N ${dataDir}/player-name ${cfg.extraArguments}";
        StateDirectory = builtins.baseNameOf dataDir;
        SupplementaryGroups = "audio";
      };
    };
  };
}