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

let
  username     = config.defaultUser or "henrov";
  homeDir      = "/home/${username}";
  wallpaperSrc = "${flakeRoot}/assets/traveldroid/Wallpapers";
  wallpaperDst = "${homeDir}/Wallpapers";
  scriptFile   = "${wallpaperDst}/set-wallpapers-at-logon.sh";
in
{
  ############################
  # Systemwide packages
  ############################
  environment.systemPackages = with pkgs; [
    swww
    waypaper
    jq
    rsync
  ];

  ############################
  # User systemd service to sync wallpapers and run script
  ############################
  systemd.user.services.wallpaperSync = {
    description = "Sync Wallpapers and run set-wallpapers-at-logon.sh";
    wants       = [ "graphical-session.target" ];
    after       = [ "graphical-session.target" ];

    serviceConfig.Type      = "oneshot";

    # Proper shell script invocation
    serviceConfig.ExecStart = ''
      ${pkgs.bash}/bin/bash -c '
        # Ensure destination exists
        mkdir -p "${wallpaperDst}"

        # Copy all wallpapers
        rsync -avu --ignore-existing "${wallpaperSrc}/" "${wallpaperDst}/"
        rsync -avu "${wallpaperSrc}/" "${wallpaperDst}/"

        # Start swww if not running
        pgrep swww >/dev/null 2>&1 || swww &

        # Run the logon wallpaper script if executable
        if [ -x "${scriptFile}" ]; then
          "${scriptFile}"
        fi
      '
    '';
    serviceConfig.Restart = "on-failure";
  };

  ############################
  # Timer to run the service every 15 minutes
  ############################
  systemd.user.timers.wallpaperSyncTimer = {
    description  = "Run wallpaperSync service every 15 minutes";
    wantedBy     = [ "timers.target" ];
    timerConfig.OnBootSec        = "1min";
    timerConfig.OnUnitActiveSec  = "15min";
    timerConfig.Persistent       = true;
  };
}