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

let
  # --- Program definition ---
  programName = "zenbrowser";

  # Assets (optional, empty if no config)
  assetPath =
    if builtins.pathExists ../../../assets/system/conf/${programName}
    then ../../../assets/system/conf/${programName}
    else null;

  programFiles =
    if assetPath != null then builtins.readDir assetPath else {};

  files = lib.genAttrs (builtins.attrNames programFiles) (name: {
    src = "${assetPath}/${name}";
  });

  # Top-level toggle for this module
  enableProgram = config.enableZenBrowser or false;

  # Default user fallback
  username = config.defaultUser or "henrov";
in
{
  # --- Option ---
  options.enableZenBrowser = lib.mkEnableOption "Install Zen Browser";

  # --- Config ---
  config = lib.mkIf enableProgram {

    # --- Deploy assets (if any) ---
    environment.etc."${programName}".source = assetPath;

    # --- System packages ---
    environment.systemPackages = [ pkgs.zen-browser ];

    # --- Example systemd service to sync assets ---
    systemd.services."${programName}-sync" = {
      description = "Sync ${programName} configuration files";
      wantedBy    = [ "multi-user.target" ];
      wants       = [ "network-online.target" ];
      after       = [ "network-online.target" ];

      serviceConfig = {
        Type = "oneshot";
        ExecStart = ''
          set -euo pipefail
          if [ -d "${assetPath}" ]; then
            for f in ${lib.concatStringsSep " " (builtins.attrNames files)}; do
              cp -u "${assetPath}/$f" "/home/${username}/.config/${programName}/$f"
            done
          fi
        '';
      };

      restartTriggers = [ assetPath ];
      path = [];
    };
  };
}