nixos-configs/common/modules/cachix.nix

{
  config,
  lib,
  pkgs,
  ...
}: let
  inherit (lib) foldl isList mergeAttrsWithFunc optionals unique;

  mergeAttrsList = list:
    foldl (mergeAttrsWithFunc (a: b:
      if isList a && isList b
      then unique (a ++ b)
      else b)) {}
    list;
in {
  environment.systemPackages = [
    (pkgs.writeShellApplication {
      name = "rebuild-no-cache";
      runtimeInputs = [config.programs.nh.package];
      text = ''
        nh os switch -- --option binary-caches "https://cache.nixos.org" "$@"
      '';
    })
  ];

  nix = {
    settings = let
      mkSubstituterConf = url: key: {
        substituters = [url];
        trusted-public-keys = optionals (key != null) [key];
      };
    in
      mergeAttrsList ([
          (mkSubstituterConf "https://cache.nixos.org" "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=")
          (mkSubstituterConf "https://hyprland.cachix.org" "hyprland.cachix.org-1:a7pgxzMz7+chwVL3/pzj6jIBMioiJM7ypFP8PwtkuGc=")
          (mkSubstituterConf "https://nix-gaming.cachix.org" "nix-gaming.cachix.org-1:nbjlureqMbRAxR1gJ/f3hxemL9svXaZF/Ees8vCUUs4=")
          (mkSubstituterConf "https://nixpkgs-wayland.cachix.org" "nixpkgs-wayland.cachix.org-1:3lwxaILxMRkVhehr5StQprHdEo4IrE8sRho9R9HOLYA=")
          (mkSubstituterConf "https://nix-community.cachix.org" "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs=")
          (mkSubstituterConf "https://viperml.cachix.org" "viperml.cachix.org-1:qZhKBMTfmcLL+OG6fj/hzsMEedgKvZVFRRAhq7j8Vh8=")
        ]
        ++ optionals (!config.services.nix-serve.enable) [
          (mkSubstituterConf "https://cache.nelim.org" "cache.nelim.org:JmFqkUdH11EA9EZOFAGVHuRYp7EbsdJDHvTQzG2pPyY=")
        ]);
  };
}