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

let
  username = config.defaultUser or "henrov";

  modulesPath = ./generated/modules;
  moduleSwitches = builtins.fromJSON (builtins.readFile ./assets/system/conf/modules.json);
  importedModules = inputs.import-tree modulesPath;

  # Keep only enabled modules
  enabledModules = lib.filterAttrs (name: _: moduleSwitches.${name} or false)
                                importedModules.imports;

  moduleList = builtins.attrValues enabledModules;

  # Recursive evaluator: forces functions → attrsets
  forceAttrs = val:
    if builtins.isFunction val then
      forceAttrs (val {})
    else if builtins.isAttrs val then
      lib.mapAttrs (_: v: forceAttrs v) val
    else if builtins.isList val then
      map forceAttrs val
    else
      val;

  # Extract fragment safely
  safeFragment = m:
    let frag =
      if builtins.hasAttr "homeManagerExtraUserFragment" m
      then m.homeManagerExtraUserFragment
      else {};
    in forceAttrs frag;

  # Merge all fragments
  mergedFragments = lib.foldl' lib.mkMerge {} (map safeFragment moduleList);

in {
  networking.hostName = "traveldroid";
  system.stateVersion = "26.05";

  home-manager.users = {
    "${username}" = mergedFragments;
  };

  # Bonus: list all imported module files
  traveldroidModules = builtins.attrNames enabledModules;
}