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

let
  username = config.defaultUser or "henrov";

  modulesPath = ./generated/modules;
  imported = inputs.import-tree modulesPath;

  moduleSwitches = import ../../../assets/system/conf/modules.conf;

  # STEP 1: evaluate all modules
  evaluatedModules =
    map (m:
      if builtins.isFunction m
      then m { inherit lib config pkgs; }
      else m
    ) imported.imports;

  # STEP 2: attach normalized names
  modulesWithNames =
    map (m: {
      name =
        if m ? _file
        then lib.removeSuffix ".nix" (builtins.baseNameOf m._file)
        else "unknown";
      value = m;
    }) evaluatedModules;

  # STEP 3: filter enabled modules
  enabledModules =
    builtins.filter (m:
      moduleSwitches.${m.name} or false
    ) modulesWithNames;

  # STEP 4: extract ONLY Home Manager user attrsets
  hmUserSets =
    map (m: m.value._module.args.hmUsers or {}) enabledModules;

  # STEP 5: debug string
  debugContents =
    builtins.concatStringsSep "\n"
      (map (m:
        let attrCount =
          if builtins.isAttrs m.value
          then builtins.length (builtins.attrNames m.value)
          else 0;
        in
          "${m.name} (${builtins.toString attrCount} attrs)"
      ) enabledModules);

  # STEP 6: FORCE trace (important!)
  tracedModules =
    builtins.trace
      ("==== Enabled modules (" +
        builtins.toString (builtins.length enabledModules) +
        ") ====\n" + debugContents)
      enabledModules;

  # STEP 7: proper debug file in store
  debugFile = pkgs.writeText "traveldroid-modules-debug.txt" debugContents;

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

  imports = [
    ./boot.nix
    ./hardware-configuration.nix
  ];

  # ✅ Correct merge: ONLY HM user attrsets
  home-manager.users =
    lib.mkMerge hmUserSets;

  # Optional: also inside VM
  environment.etc."traveldroid-modules-debug.txt".text = debugContents;

  # Expose debug file as build output
  system.build.modulesDebug = debugFile;
}