{ pkgs, config, ... }:
let
  fehCmd = "${pkgs.feh}/bin/feh";
  backgrounds_directory = ~/Immagini/Sfondi ;
  update_time = 10;
in {
  home.file.".local/bin/update_background.sh" = {
    text = ''
      #!${pkgs.bash}/bin/bash
      image=`find ${backgrounds_directory} -type f | grep -v "/\." | shuf -n 1`
      ${fehCmd} --bg-fill --no-fehbg "$image"
    '';
    target = ".local/bin/update_background.sh";
    executable = true;
  };

  systemd.user.services."update-background" = {
    Unit = {
      Description = "Update the desktop background";
      After = [ "graphical-session.target" ];
      PartOf = [ "graphical-session.target" ];
      RequiresMountsFor = [ "/home/bertof/Immagini" ];
    };
    Install = {
      WantedBy = [ "graphical-session.target" ];
    };
    Service = {
      ExecStart = "${config.home.homeDirectory}/${config.home.file.".local/bin/update_background.sh".target}";
    };
  };

  systemd.user.timers."update-background" = {
    Unit = {
      Description="Run update-background every ${toString update_time} minutes";
      PartOf = [ "graphical-session.target" ];
      After = [ "graphical-session.target" ];
    };
    Timer = {
      OnUnitActiveSec="${toString update_time}m";
    };
    Install = {
      WantedBy = [ "graphical-session.target" ];
    };
  };
}