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

{
  imports =
    [ # Include the results of the hardware scan.
      ./hardware-configuration.nix
    ];

  # Bootloader.
  boot.loader.grub.enable = true;
  boot.loader.grub.device = "/dev/sda";
  boot.loader.grub.useOSProber = true;

  boot.kernelParams = [ "quiet" ];
  boot.extraModulePackages = [ config.boot.kernelPackages.amneziawg ];
  boot.kernelModules = [ "amneziawg" ];

  programs.nix-ld.enable = true;
  programs.nix-ld.libraries = with pkgs; [
    stdenv.cc.cc
    zlib
    fuse3
    icu
    nss
    openssl
    curl
    expat
  ];

  networking.hostName = "nixos-vm";
  networking.networkmanager.enable = true;
  time.timeZone = "Europe/Moscow";

  i18n.defaultLocale = "en_US.UTF-8";

  i18n.extraLocaleSettings = {
    LC_ADDRESS = "ru_RU.UTF-8";
    LC_IDENTIFICATION = "ru_RU.UTF-8";
    LC_MEASUREMENT = "ru_RU.UTF-8";
    LC_MONETARY = "ru_RU.UTF-8";
    LC_NAME = "ru_RU.UTF-8";
    LC_NUMERIC = "ru_RU.UTF-8";
    LC_PAPER = "ru_RU.UTF-8";
    LC_TELEPHONE = "ru_RU.UTF-8";
    LC_TIME = "ru_RU.UTF-8";
  };

  services.xserver.enable = true;
  services.xserver.displayManager.sddm.enable = true;
  services.xserver.displayManager.sddm.wayland.enable = true;
  services.xserver.desktopManager.plasma5.enable = true;

  environment.sessionVariables.NIXOS_OZONE_WL = "1";

  # Configure keymap in X11
  services.xserver.xkb = {
    layout = "us";
    variant = "";
  };

  # Enable CUPS to print documents.
  services.printing.enable = true;

  services.pulseaudio.enable = false;
  security.rtkit.enable = true;
  services.pipewire = {
    enable = true;
    alsa.enable = true;
    alsa.support32Bit = true;
    pulse.enable = true;
  };

  # Define a user account. Don't forget to set a password with ‘passwd’.
  users.users.ada = {
    isNormalUser = true;
    description = "ada";
    extraGroups = [ "networkmanager" "wheel" ];
    packages = with pkgs; [
      vim
      neovim
      code
      jetbrains.idea-community
      tmux
      zsh
      oh-my-zsh
      fzf
      ripgrep
      fd
      bat
      eza
      lsd
      git
      gh
      lazygit
      curl
      wget
      jq
      nix-output-monitor
      nvd
      nix-tree
      comma
      htop
      btop
      tree
    ];
  };



  environment.systemPackages = with pkgs; [
    vim
    wget
    git
    curl
    amneziawg-tools
    nix-output-monitor
    nvd
    nix-tree
    comma
    htop
    neofetch
  ];

  nix = {
    package = pkgs.nix;
    settings = {
      experimental-features = [ "nix-command" "flakes" ];
      auto-optimise-store = true;
    };
    gc = {
      automatic = true;
      dates = "weekly";
      options = "--delete-older-than 7d";
    };
  };

  nixpkgs.config.allowUnfree = true;

  programs.firefox.enable = true;
  programs.amnezia-vpn.enable = true;
  programs.mtr.enable = true;
  programs.gnupg.agent = {
    enable = true;
    enableSSHSupport = true;
  };

  services.openssh = {
    enable = true;
    settings = {
      PasswordAuthentication = false;
      PubkeyAuthentication = true;
    };
  };

  # Open ports in the firewall.
  networking.firewall.allowedTCPPorts = [ 22 ];

  virtualisation.virtualbox.guest.enable = true;
  virtualisation.virtualbox.guest.dragAndDrop = true;
  virtualisation.virtualbox.guest.clipboard = true;

  system.stateVersion = "25.05";
}