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

{
  system.build.tarball = pkgs.callPackage (nixpkgs + "/nixos/lib/make-system-tarball.nix") {
    extraArgs = "--owner=0";
    compressCommand = "cat";
    compressionExtension = "";

    storeContents = [
      {
        object = config.system.build.toplevel;
        symlink = "none";
      }
    ];

    contents = [
      {
        source = config.system.build.toplevel + "/init";
        target = "/sbin/init";
      }
    ];

    extraCommands = "mkdir -p proc sys dev";
  };

  boot.initrd.kernelModules = [ ];
  boot.initrd.includeDefaultModules = false;
  boot.initrd.availableKernelModules = lib.mkForce [ "usbhid" ];
  boot.kernelModules = [ ];
  boot.extraModulePackages = [ ];

  swapDevices = [ ];

  hardware.enableRedistributableFirmware = true;
  powerManagement.cpuFreqGovernor = lib.mkDefault "performance";

  nixpkgs.config.packageOverrides = pkgs: {
    makeModulesClosure = x:
      # prevent kernel install fail due to missing modules
      pkgs.makeModulesClosure (x // { allowMissing = true; });
  };
  boot = {
    # HACK
    isContainer = true;
    loader.initScript.enable = true;
    tmpOnTmpfs = true;
    postBootCommands = ''
      # nixos-rebuild also requires a "system" profile and an
      # /etc/NIXOS tag.
      touch /etc/NIXOS
      ${config.nix.package}/bin/nix-env -p /nix/var/nix/profiles/system --set /run/current-system
    '';
  };
  fileSystems."/" = {
    fsType = "tmpfs";
    options = [ "mode=0755" ];
  };
  fileSystems."/etc" = {
    fsType = "tmpfs";
    options = [ "mode=0755" ];
  };
  fileSystems."/var" = {
    fsType = "tmpfs";
    options = [ "mode=0755" ];
  };
  hardware.raspberry-pi."4" = {
    # fkms-3d.enable = true;
  };

  c3d2 = {
    isInHq = true;
    mergeHostsFile = true;
    hq.interface = "eth0";
    hq.statistics.enable = false;
    audioServer.enable = true;
    k-ot.enable = true;
    autoUpdate = false;
  };

  nix = {
    buildCores = 4;
    maxJobs = 2;
  };

  networking = {
    hostName = "rpi-netboot"; # Define your hostname.
    useDHCP = false;
    interfaces.eth0.useDHCP = true;
    firewall.enable = false;
  };

  environment.systemPackages = with pkgs; [
    libraspberrypi
    raspberrypi-eeprom
    vim
    wget
    # mpv
    # youtube-dl
    # ncpamixer
    # pulseaudio # required for pactl
    # #chromium
    # # firefox
    # pavucontrol
  ];

  # programs.tmux.enable = true;

  # Do not log to flash:
  services.journald.extraConfig = ''
    Storage=volatile
  '';

  # Enable the OpenSSH daemon.
  services.openssh = {
    enable = true;
  };
  security.sudo = {
    enable = true;
    wheelNeedsPassword = false;
  };

  # Select internationalisation properties.
  console = {
    font = "${pkgs.terminus_font}/share/consolefonts/ter-u28n.psf.gz";
    keyMap = "de";
  };

  # # Enable the X11 windowing system.
  # services.xserver.enable = true;
  # services.xserver.layout = "de";
  # services.xserver.xkbOptions = "eurosign:e";

  # services.xserver.displayManager = {
  #   lightdm = { enable = true; };
  #   autoLogin = {
  #     enable = true;
  #     user = "k-ot";
  #   };
  #   defaultSession = "gnome-xorg";
  # };
  # services.xserver.desktopManager = {
  #   gnome.enable = true;
  #   # kodi.enable = true;
  # };
  # systemd.user.services.x11vnc = {
  #   description = "X11 VNC server";
  #   wantedBy = [ "graphical-session.target" ];
  #   partOf = [ "graphical-session.target" ];
  #   serviceConfig = {
  #     ExecStart = ''
  #       ${pkgs.x11vnc}/bin/x11vnc -shared -forever -passwd k-ot
  #     '';
  #     RestartSec = 3;
  #     Restart = "always";
  #   };
  # };

  # This value determines the NixOS release from which the default
  # settings for stateful data, like file locations and database versions
  # on your system were taken. It‘s perfectly fine and recommended to leave
  # this value at the release version of the first install of this system.
  # Before changing this value read the documentation for this option
  # (e.g. man configuration.nix or on https://nixos.org/nixos/options.html).
  system.stateVersion = "21.11"; # Did you read the comment?
}