# Power user optimizations and better defaults for NixOS
{ config, pkgs, lib, ... }:

{
  # Enable flakes and new nix command by default
  nix = {
    settings = {
      # Enable flakes and new nix command
      experimental-features = [ "nix-command" "flakes" ];
      
      # Optimize builds
      auto-optimise-store = true;
      max-jobs = "auto";
      cores = 0; # Use all available cores
      
      # Better substituters for faster downloads
      substituters = [
        "https://cache.nixos.org/"
        "https://nix-community.cachix.org"
        "https://cache.garnix.io"
      ];
      trusted-public-keys = [
        "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
        "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
        "cache.garnix.io:CTFPyKSLcx5RMJKfLo5EEPUObbCWZKkK1YDH9c6MCSM="
      ];
      
      # Optimize networking
      http-connections = 128;
      max-substitution-jobs = 128;
      
      # Better compression
      compress-build-log = true;
      
      # Security
      require-sigs = true;
      
      # Keep build dependencies for debugging
      keep-derivations = true;
      keep-outputs = true;
      
      # Better sandbox
      sandbox = true;
      
      # Trusted users for nix daemon
      trusted-users = [ "root" "@wheel" ];
    };
    
    # Automatic garbage collection
    gc = {
      automatic = true;
      dates = "weekly";
      options = "--delete-older-than 7d";
    };
    
    # Optimize store automatically
    optimise = {
      automatic = true;
      dates = [ "03:45" ];
    };
    
    # Nix registry for flakes
    registry = {
      nixpkgs.flake = lib.mkDefault {
        type = "github";
        owner = "NixOS";
        repo = "nixpkgs";
        ref = "nixos-unstable";
      };
    };
    
    # Nix path for backwards compatibility
    nixPath = [
      "nixpkgs=flake:nixpkgs"
    ];
  };
}