{ config, pkgs, devenv, ... }:

{
  # enable flakes globally
  nix.settings.experimental-features = [ "nix-command" "flakes" ];

  # Set your time zone.
  time.timeZone = "Asia/Shanghai";

  # Select internationalisation properties.
  i18n.defaultLocale = "en_US.UTF-8";

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

  # all fonts are linked to /nix/var/nix/profiles/system/sw/share/X11/fonts
  fonts = {
    # use fonts specified by user rather than default ones
    enableDefaultFonts = false;
    fontDir.enable = true;

    fonts = with pkgs; [
      # icon fonts
      material-design-icons
      font-awesome

      # 思源系列字体是 Adobe 主导的。其中汉字部分被称为「思源黑体」和「思源宋体」，是由 Adobe + Google 共同开发的
      source-sans       # 无衬线字体，不含汉字。字族名叫 Source Sans 3 和 Source Sans Pro，以及带字重的变体，加上 Source Sans 3 VF
      source-han-sans   # 思源黑体

      # nerdfonts
      (nerdfonts.override { fonts = [
        "FiraCode"
        "JetBrainsMono"
        "Iosevka"
      ];})
    ];

    # user defined fonts
    # the reason there's Noto Color Emoji everywhere is to override DejaVu's
    # B&W emojis that would sometimes show instead of some Color emojis
    fontconfig.defaultFonts = {
      sansSerif = [ "Noto Sans" "Noto Color Emoji" ];
      monospace = [ "JetBrainsMono Nerd Font" "Noto Color Emoji" ];
      emoji = [ "Noto Color Emoji" ];
    };
  };

  # networking.firewall.allowedTCPPorts = [ ... ];
  # networking.firewall.allowedUDPPorts = [ ... ];
  # Or disable the firewall altogether.
  networking.firewall.enable = false;

  # Enable the OpenSSH daemon.
  services.openssh = {
    enable = true;
    settings = {
      X11Forwarding = true;
      PermitRootLogin = "no";         # disable root login
      PasswordAuthentication = false; # disable password login
    };
    openFirewall = true;
  };

  # Allow unfree packages
  nixpkgs.config.allowUnfree = true;

  # List packages installed in system profile. To search, run:
  # $ nix search wget
  environment.systemPackages = with pkgs; [
    neovim # Do not forget to add an editor to edit configuration.nix! The Nano editor is also installed by default.
    wget
    curl
    aria2
    git      # used by nix flakes
    git-lfs  # used by huggingface models
  ];

  # replace default editor with neovim
  environment.variables.EDITOR = "nvim";

  # for power management
  services.power-profiles-daemon = {
    enable = true;
  };
  services.upower.enable = true;
}