{...}: {
  services.hypridle = {
    enable = true;
    settings = {
      general = {
        lock_cmd = "pidof hyprlock || hyprlock"; # avoid starting multiple hyprlock instances.
        before_sleep_cmd = "loginctl lock-session"; # lock before suspend.
        after_sleep_cmd = "hyprctl dispatch dpms on && agu"; # avoid needing to press a key twice to turn on the display.
      };

      listener = [
        # {
        #   timeout = 150;
        #   on-timeout = "brightnessctl -s set 10"; # set monitor backlight to minimum, avoid 0 on OLED monitor.
        #   on-resume = "brightnessctl -r"; # restore monitor backlight.
        # }
        # {
        #   timeout = 150;
        #   on-timeout = "brightnessctl -sd rgb:kbd_backlight set 0"; # turn off keyboard backlight.
        #   on-resume = "brightnessctl -rd rgb:kbd_backlight"; # turn on keyboard backlight.
        # }
        # {
        #   timeout = 300;
        #   on-timeout = "loginctl lock-session"; # lock screen when timeout has passed.
        # }
        # {
        #   timeout = 330;
        #   on-timeout = "hyprctl dispatch dpms off"; # screen off after 5.5min.
        #   on-resume = "hyprctl dispatch dpms on && brightnessctl -r"; # screen on and restore brightness on resume.
        # }
        {
          timeout = 300;
          on-timeout = "systemctl suspend"; # suspend PC after 30min.
        }
      ];
    };
  };
}