dotfiles-nixos/nixos/modules/nixconfig.nix

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

{
  nixpkgs = {
    # You can add overlays here
    overlays = [
      # If you want to use 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;
    };
  };

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

  nix.gc.automatic = true;
  nix.gc.options = "--delete-older-than 30d";

}