{
  pkgs,
  userName,
  ...
}:let
  livekitKeyFile = "/var/lib/livekit/livekit.key";
  matrixRegistrationTokenFile = "/var/lib/matrix.key";
in {
  imports = [
    ../../pwrMgmt
  ];

  # Enable flakes for NixOS
  nix.settings.experimental-features = ["nix-command" "flakes"];

  nix.settings = {
    download-buffer-size = 134217728;  # 128 MiB in bytes
  };

  # Custom kernel/boot stuff
  boot.kernelPackages = pkgs.linuxPackages_latest;
  #  boot.loader.systemd-boot.enable = true; # TODO: check on this
  #  boot.loader.efi.canTouchEfiVariables = true;

  # Set your timezone
  time.timeZone = "America/Detroit";

  # Enable OpenSSH
  services.openssh = {
    enable = true;
    settings.PermitRootLogin = "no";
    settings.PasswordAuthentication = false;
  };

  # Enable keyring
  services.gnome.gnome-keyring.enable = true;

  # Enable GnuPG
  programs.gnupg.agent = {
    enable = true;
    enableSSHSupport = true;
  };

  # Enable SUID wrappers (some programs need them)
  programs.mtr.enable = true;

  # Enable Polkit
  security.polkit.enable = true;

  # Power management (see ../../pwrMgmt/default.nix)
  pwrMgmt = {
    enable = true;
    cpuFreqGovernor = "performance";
    powertop.enable = false;
  };

  # Firewall settings (fallback, upstream way of doing things)
  networking.firewall = {
    enable = true;

    allowedTCPPorts = [
      80
      443
      8448
      3478
      5349
      7880
      7881
      8080
      8081
    ];

    allowedUDPPorts = [
      3478
      8448
    ];

    allowedUDPPortRanges =[
      # TURN UDP relays
      { 
        from = 49000;
        to = 50000;
      }
      # 
      {
        from = 50100;
        to = 50200;
      }
    ];
  };

  # Add username to groups "wheel" and "video" - more may be added here later
  users.users.${userName} = {
    openssh.authorizedKeys.keys = [
      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIFV9eSc9L+aJLoKoexq2f/jb5rpyZnhuGiyhS8YQAbaS wyatt@wyattjmiller.com"
      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIO4WKvKnnYpTbzZHFEslOKyfiiMqWxhW3AfX6E7ACmYU wyatt@wyattjmiller.com"
    ];
    extraGroups = ["wheel" "video" "network"];
  };

  # fail2ban
  services.fail2ban = {
    enable = true;
    package = pkgs.fail2ban;
    maxretry = 5;
    bantime = "3h";
    bantime-increment = {
      enable = true;
      rndtime = "10m";
    };
  };

  # Matrix server
  services.matrix-tuwunel = {
    enable = true;
    package = pkgs.matrix-tuwunel;
    settings = {
      global = {
        server_name = "chat.wyattjmiller.com";
        allow_encryption = true;
        allow_federation = true;
        allow_registration = true;
        registration_token = matrixRegistrationTokenFile;
        allow_unstable_room_versions = false;
        allow_experimental_room_versions = false;
        # encryption_enabled_by_default_for_room_type = false;
        zstd_compression = true;
        new_user_displayname_suffix = "✨";
        max_request_size = 1048575600; # 100MB in bytes, for file uploads
        database_backup_path = "/var/lib/tuwunel/database_backups";
        database_backups_to_keep = 2;

        address = [
          "127.0.0.1"
          "::1"
        ];
        port = [ 8008 ];

        well_known = {
          client = "https://chat.wyattjmiller.com";
          server = "chat.wyattjmiller.com:443";
          support_email = "wyatt@wyattjmiller.com";
          support_mxid = "@wymiller:chat.wyattjmiller.com";
          
          rtc_transports = [{
            type = "livekit";
            livekit_service_url = "https://rtc.wyattjmiller.com";
          }];
        };
      };
    };
  };

  # TURN/STUN server
  services.coturn = {
    enable = true;
    no-cli = false;
    no-tcp-relay = false;
    realm = "turn.wyattjmiller.com";
    min-port = 49000;
    max-port = 50000;

    # TODO: fill out this extraConfig option a bit more with denial of private IP addresses
    extraConfig = ''
      verbose
      no-multicast-peers
    '';
  };

  # LiveKit (Matrix RTC)
  services.livekit = {
    enable = true;
    package = pkgs.livekit;
    openFirewall = true;
    keyFile = livekitKeyFile;
    settings = {
      port = 7880;
      room.auto_create = true;
      rtc = {
        use_external_ip = true;
      };
    };
  };

  # Reverse proxy
  services.caddy = {
    enable = true;
    package = pkgs.caddy;
    virtualHosts = {
      "chat.wyattjmiller.com" = {
        extraConfig = ''
          encode zstd gzip
          reverse_proxy localhost:8008
        '';
      };
      "chat.wyattjmiller.com:8448" = {
        extraConfig = ''
          encode zstd gzip
          reverse_proxy localhost:8008
        '';
      };
      "rtc.wyattjmiller.com" = {
        extraConfig = ''
          @jwt_service {
            path /sfu/get* /healthz*
          }

          handle @jwt_service {
            reverse_proxy localhost:8081
          }

          handle {
            reverse_proxy localhost:7880 {
              header_up Connection "upgrade"
              header_up Upgrade {http.request.header.Upgrade}
            }
          }
        '';
      };
    };
  };

  # LiveKit JWT service
  services.lk-jwt-service = {
    enable = true;
    port = 8080;
    livekitUrl = "wss://rtc.wyattjmiller.com";
    keyFile = livekitKeyFile;
    # settings = {
    #   keys = {
    #   	"2rew2444" = "aAssWw18asef3fa5ldehHhjunlijj8x=";
    #   };
    # };
  };

  # Generate LiveKit key if it doesn't exist
  systemd.services.livekit-key = {
    before = [ "lk-jwt-service.service" "livekit.service" ];
    wantedBy = [ "multi-user.target" ];
    path = with pkgs; [ coreutils openssl ];
    script = ''
      set -eu

      if [ -f "${livekitKeyFile}" ]; then
        exit 0
      fi

      install -d -m 0700 "$(dirname "${livekitKeyFile}")"

      API_KEY="$(openssl rand -hex 8)"
      API_SECRET="$(openssl rand -hex 32)"

      # keyFile format for nixpkgs services.livekit.keyFile:
      # a YAML map of apiKey -> apiSecret (no surrounding "keys:" key)
      umask 077
      printf '%s: %s\n' "$API_KEY" "$API_SECRET" > "${livekitKeyFile}"
    '';
    serviceConfig = {
      Type = "oneshot";
      User = "root";
    };
  };

  system.stateVersion = "25.11";
}