{
  config,
  username,
  ...
}:
let
  cfg = config.modules.system;
in
{
  nix = {
    settings = {
      allowed-users = [ username ];
      trusted-users = [
        "@wheel"
        username
      ];
      experimental-features = [
        "nix-command"
        "flakes"
      ];
      extra-substituters = [
        "https://walker.cachix.org"
        "https://walker-git.cachix.org"
      ];
      extra-trusted-public-keys = [
        "walker.cachix.org-1:fG8q+uAaMqhsMxWjwvk0IMb4mFPFLqHjuvfwQxE4oJM="
        "walker-git.cachix.org-1:vmC0ocfPWh0S/vRAQGtChuiZBTAe4wiKDeyyXM0/7pM="
      ];
    };
  };

  console.keyMap = cfg.keyMap;
  time.timeZone = cfg.timeZone;
  i18n = {
    defaultLocale = cfg.locale;
    extraLocaleSettings = {
      LC_ADDRESS = cfg.locale;
      LC_IDENTIFICATION = cfg.locale;
      LC_MEASUREMENT = cfg.locale;
      LC_MONETARY = cfg.locale;
      LC_NAME = cfg.locale;
      LC_NUMERIC = cfg.locale;
      LC_PAPER = cfg.locale;
      LC_TELEPHONE = cfg.locale;
      LC_TIME = cfg.locale;
    };
  };

  system.stateVersion = "26.05";
}