NixOS/niri/autostart.nix

{ config, pkgs, username, project, ... }:
{
  
#To show logs of services run: 
#journalctl --user-unit={service-name} --user
  systemd.user.services.niri-waybar = {
    description = "Waybar status bar for Niri";
    
    # "wantedBy" replaces the [Install] section
    wantedBy = [ "graphical-session.target" ];
    
    # "partOf" and "after" replace the [Unit] section dependencies
    partOf = [ "graphical-session.target" ];
    after = [ "graphical-session.target" ];

    # [Unit] configuration goes here
    unitConfig = {
      # This checks the environment variable to ensure we are in Niri
      ConditionEnvironment = "XDG_CURRENT_DESKTOP=niri";
    };

    # [Service] configuration goes here
    serviceConfig = {
      ExecStart = "${pkgs.waybar}/bin/waybar";
      Restart = "on-failure";
      RestartSec = "1s";
    };
  };

  # 2. The Niri Session Cleanup Service
  # This service starts when the graphical session starts, and when it stops,
  # it forcibly stops the graphical-session.target to ensure a clean state for the next login.
  systemd.user.services.niri-session-manager = {
    description = "Niri Session Management";
    wantedBy = [ "graphical-session.target" ];
    partOf = [ "graphical-session.target" ];
    
    # Only run this cleanup logic for Niri
    unitConfig.ConditionEnvironment = "XDG_CURRENT_DESKTOP=niri";

    serviceConfig = {
      Type = "simple";
      # A dummy command that stays alive. 'sleep infinity' is low resource.
      ExecStart = "${pkgs.coreutils}/bin/sleep infinity";
      
      # IMPORTANT: When this service stops (which happens when niri kills its children),
      # it brings down the whole target.
      ExecStopPost = "${pkgs.systemd}/bin/systemctl --user stop graphical-session.target";
    };
  };
}