{ lib, config, pkgs, flakeRoot, home-manager, ... }:

let
  # Path to Waybar assets
  assetPath = "${flakeRoot}/assets/system/conf/waybar";

  # Determine the username safely
  username =
    builtins.head (builtins.filter (u: config.users.users.${u}.isNormalUser != false)
      (builtins.attrNames config.users.users));

  # Compute the Home Manager user map safely
  hmUser = config.home-manager.users.${username} or {};
in
{
  ##############################
  # System-wide Waybar package
  ##############################
  environment.systemPackages = [ pkgs.waybar ];

  ##############################
  # Home Manager Waybar config
  ##############################
  home-manager.users = lib.recursiveUpdate config.home-manager.users {
    ${username} = lib.recursiveUpdate hmUser {
      home.file = lib.recursiveUpdate (hmUser.home.file or {}) {
        ".config/waybar/config" = { source = "${assetPath}/config"; };
        ".config/waybar/style.css" = { source = "${assetPath}/style.css"; };
      };
    };
  };

  ##############################
  # Optional: Systemd --user service for Waybar
  ##############################
  systemd.user.services.waybar = {
    description = "Waybar for Hyprland";
    after = [ "graphical-session.target" ];

    serviceConfig = {
      ExecStart = "${pkgs.waybar}/bin/waybar";
      Restart = "always";
      # Use the runtime dir provided by systemd, avoids null/UID issues
      Environment = ''
        WAYLAND_DISPLAY=${config.environment.sessionVariables.WAYLAND_DISPLAY or "wayland-0"}
        XDG_CURRENT_DESKTOP=Hyprland
      '';
    };

    wantedBy = [ "default.target" ];
  };
}