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

{
  boot.initrd.kernelParams = [
    "verbose"
  ];

  swapDevices = [ ];

  hardware.enableRedistributableFirmware = true;
  hardware.bluetooth.enable = 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; });
  };

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

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

  # volatile system: everything is tmpfs
  fileSystems."/" = {
    fsType = "tmpfs";
    options = [ "mode=0755" ];
  };
  fileSystems."/etc" = {
    fsType = "tmpfs";
    options = [ "mode=0755" ];
  };
  fileSystems."/var" = {
    fsType = "tmpfs";
    options = [ "mode=0755" ];
  };

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

  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?
}