{ pkgs, lib, self, ... }: {
  # List packages installed in system profile. To search by name, run:
  # $ nix-env -qaP | grep wget
  environment.systemPackages = [ ];

  nix.settings = {
    experimental-features = [ "nix-command" "flakes" ];
    auto-optimise-store = true;
  };

  environment.shells = with pkgs; [ bashInteractive zsh fish ];

  # Auto upgrade nix package and the daemon service.
  services.nix-daemon.enable = true;

  # Enable alternative shell support in nix-darwin.
  # programs.fish.enable = true;

  services.yabai =
    let
      gap = 10;

      gapListParts = builtins.map
        (x: lib.attrsets.nameValuePair (x + "_padding") gap)
        [ "top" "bottom" "left" "right" ];

      gapSettings = (builtins.listToAttrs gapListParts) // { window_gap = gap; };
    in
    {
      enable = true;
      enableScriptingAddition = true;
      config = {
        layout = "bsp";
        window_shadow = "float";

        mouse_modifier = "fn";
        mouse_action1 = "move";
        mouse_action2 = "resize";
        focus_follows_mouse = "autoraise";
        mouse_follows_focus = "off";
        window_topmost = "off";
      } // gapSettings;
      extraConfig = ''
        yabai -m rule --add app="^System Settings$" manage=off
        yabai -m rule --add app="Python" manage=off
        yabai -m rule --add app="macroquad_playground" manage=off
        yabai -m rule --add app="^coreautha$" manage=off
      '';
    };

  home-manager.sharedModules = [
    {
      home.file.".config/yabai/yabaiExe".source = lib.getExe pkgs.yabai;
      home.packages = with pkgs; [ yabai ];
    }
  ];

  security.pam.enableSudoTouchIdAuth = true;

  users.users.zynh = {
    name = "zynh";
    home = "/Users/zynh";
  };

  home-manager = {
    users = { "zynh" = import ./home.nix; };
    backupFileExtension = "backup";
  };

  fonts.packages = with pkgs; [
    (nerdfonts.override { fonts = [ "JetBrainsMono" ]; })
  ];

  # Set Git commit hash for darwin-version.
  system.configurationRevision = self.rev or self.dirtyRev or null;
  # $ darwin-rebuild changelog
  system.stateVersion = 5;
}