{ config, lib, osConfig, ... }:

let
  cfg = config.my.nix;
in {
  options.my.nix = {
    gc = lib.mkEnableOption null // {
      default = true;
    };
  };

  config = {
    xdg.configFile = {
      "nixpkgs/config.nix".text = lib.generators.toPretty {multiline = true;} {
        inherit (osConfig.nixpkgs.config) allowUnfree;
      };
    };

    systemd.user = lib.mkIf cfg.gc {
      services.nix-gc = {
        Unit = {
          Description = "Nix User Garbage Collector";
        };
        Service = {
          ExecStart = "${osConfig.nix.package}/bin/nix-collect-garbage ${osConfig.nix.gc.options}";
        };
      };

      timers = {
        nix-gc = lib.mkIf osConfig.nix.gc.automatic {
          Timer = osConfig.systemd.timers.nix-gc.timerConfig;
          Install = {
            WantedBy = [ "timers.target" ];
          };
        };
      };
    };
  };
}