{ inputs, outputs, config, lib, ... }:

{
  security = {
    sudo.enable = true;
    polkit.enable = true;
  };

  services = {
    printing.enable = true;
    acpid.enable = true;
    upower.enable = true;
  };

  nix = {
    # This will add each flake input as a registry
    # To make nix3 commands consistent with your flake
    registry = lib.mapAttrs (_: value: { flake = value; }) inputs;

    # This will additionally add your inputs to the system's legacy channels
    # Making legacy nix commands consistent as well, awesome!
    nixPath = lib.mapAttrsToList (key: value: "${key}=${value.to.path}") config.nix.registry;


    settings = {
      # Enable flakes and new 'nix' command
      experimental-features = "nix-command flakes";
      substituters = [
        "https://mirrors.ustc.edu.cn/nix-channels/store"
        "https://nix-community.cachix.org"
        "https://cache.nixos.org/"
      ];
      trusted-public-keys = [
        "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
      ];
      trusted-users = [ "root" ];
      build-users-group = "nixbld";
      
      # Enable local binary cache
      keep-outputs = true;
      keep-derivations = true;

      max-jobs = "auto";
      cores = 0;  # Use all available cores

      # Deduplicate and optimize nix store during build
      # auto-optimise-store = true;
    };

    gc = {
      automatic = true;          # Enable automatic garbage collection
      dates = "weekly";         # Execute garbage collection weekly
      persistent = true;        # Keep settings after reboot
      randomizedDelaySec = "15min";  # Add up to 15 minutes of random delay
      options = "--delete-older-than 30d";  # Delete files older than 30 days
    };

    # Automatically run garbage collection whenever there is not enough space left
    # Free up to 5GiB whenever there is less than 1GiB left:
    extraOptions = ''
      min-free = ${toString (1 * 1024 * 1024 * 1024)}
      max-free = ${toString (5 * 1024 * 1024 * 1024)}
    '';
  };

  nixpkgs = {
    # You can add overlays here
    overlays = [
      # Add overlays your own flake exports (from overlays and pkgs dir):
      outputs.overlays.additions
      outputs.overlays.modifications
      outputs.overlays.unstable-packages

      # You can also add overlays exported from other flakes:
      # neovim-nightly-overlay.overlays.default

      # Or define it inline, for example:
      # (final: prev: {
      #   hi = final.hello.overrideAttrs (oldAttrs: {
      #     patches = [ ./change-hello-to-hi.patch ];
      #   });
      # })
    ];
    # Configure your nixpkgs instance
    config = {
      # Disable if you don't want unfree packages
      allowUnfree = true;
    };
  };
}