#!/bin/bash

set -e
set -u

FLAGFILE="$HOME/.screensaver-pause.flag"

usage() {
  echo "$0 [<minutes>]"
}

while getopts "h" OPTION; do
  case "$OPTION" in
    h)
      usage
      exit 0
    ;;
    *)
      usage >&2
      exit 1
  esac
done
shift $(($OPTIND - 1))

if [ "$#" -gt 1 ]; then
  usage >&2
  exit 1
elif [ "$#" -eq 1 ]; then
  timeout="$1"
else
  timeout=60
fi

touch -d "+$timeout minutes" "$FLAGFILE"
(
while find "$FLAGFILE" -mmin -0 2>/dev/null | grep -q .; do
  qdbus org.freedesktop.ScreenSaver /ScreenSaver SimulateUserActivity >/dev/null
  sleep 30
done
rm -f "$FLAGFILE"
) &
disown