let
  mods = import ./modules;
  users = import ./users;
  sources = import ./npins;
  inherit (import sources.nix-patches { patchFile = ./patches; }) mkNixpkgsSrc;

  unstable = {
    nixpkgs = import (mkNixpkgsSrc {
      src = sources.nixpkgs-unstable;
      version = "unstable";
    }) { };
    home-manager = "${sources.home-manager-unstable}/nixos";
    nixvim = import sources.nixvim-unstable;
  };
  stable = {
    nixpkgs = import (mkNixpkgsSrc {
      src = sources.nixpkgs-stable;
      version = "stable";
    }) { };
    home-manager = "${sources.home-manager-stable}/nixos";
    nixvim = import sources.nixvim-stable;
  };
  inherit (unstable.nixpkgs) lib;

  nodes = lib.mapAttrs' (name: _: {
    name = lib.removeSuffix ".nix" name;
    value = import ./machines/${name};
  }) (builtins.readDir ./machines);

  nodes-meta = lib.mapAttrs (_: n: n.meta) nodes;
in
{
  meta = rec {
    inherit (unstable) nixpkgs;
    specialArgs = {
      inherit mods users sources;
      meta = nodes-meta;
      versions = {
        inherit unstable stable;
      };
    };
    nodeNixpkgs = lib.mapAttrs (
      _: node:
      lib.foldl (
        pkgs: patch:
        import (mkNixpkgsSrc {
          src = pkgs;
          version = patch;
        }) { }
      ) (if node.unstable then unstable else stable).nixpkgs (node.nixPatches or [])
    ) nodes-meta;
    nodeSpecialArgs = lib.mapAttrs (name: node: {
      inherit (node) unstable;
      self-version = (if node.unstable then unstable else stable) // {
        nixpkgs = nodeNixpkgs."${name}";
      };
    }) nodes-meta;
  };
  defaults =
    {
      name,
      ...
    }:
    {
      imports = [ ./kat ];
      networking.hostName = name;
    };
}
// lib.mapAttrs (_: n: n.config) nodes