{ lib, ... }:

with lib;
let
  hostname-from-file = filename: builtins.replaceStrings [".nix"] [""] filename;

  is-nix-file = filename: type: (builtins.match ".+\.nix$" filename) != null;
  is-regular-file = filename: type: type == "regular" || type == "link";

  host-files = host-path:
    attrNames
      (filterAttrs is-nix-file
        (filterAttrs is-regular-file
          (builtins.readDir host-path)));

  hosts = host-path:
    map hostname-from-file (host-files host-path);
in {
  base-host-config = host-path: let
    load-host-file = hostname: import (host-path + "/${hostname}.nix");
  in genAttrs (hosts host-path) (hostname: load-host-file hostname);

  host-list = host-path: hosts host-path;
}