set -o pipefail

target_user="${SYSTEM_NOTIFY_USER:-alisceon}"
urgency="${1:-normal}"
title="${2:-System task}"
body="${3:-}"

uid="$(id -u "$target_user" 2>/dev/null || true)"
[ -n "$uid" ] || exit 0

runtime_dir="/run/user/$uid"
bus="$runtime_dir/bus"
[ -S "$bus" ] || exit 0

runuser -u "$target_user" -- env \
  XDG_RUNTIME_DIR="$runtime_dir" \
  DBUS_SESSION_BUS_ADDRESS="unix:path=$bus" \
  notify-send \
    --app-name="NixOS maintenance" \
    --urgency="$urgency" \
    "$title" \
    "$body" \
  || exit 0