#!/bin/bash

if [ $# -ne 0 ]; then
  >&2 echo 'check-if-bareos-backup-is-running: too many arguments'
  exit 2
fi

bareos_pid=$(
  pgrep -xf '(.*/)?bareos-fd' \
  | head -n1
)

if [ -z "${bareos_pid}" ]; then
  >&2 echo 'check-if-bareos-backup-is-running: cannot find running bareos-fd'
  exit 2
fi

if ! grep -qxF bareos-fd "/proc/${bareos_pid}/comm"; then
  >&2 echo 'check-if-bareos-backup-is-running: cannot find running bareos-fd'
  exit 2
fi

if [ $(whoami) != 'root' ]; then
  >&2 echo 'check-if-bareos-backup-is-running: must be run as root'
  exit 2
fi

time_out=$((
  $(date +%s)+30
))
was=$(
  sed '
    s/^read_bytes: //
    t
    d
  ' "/proc/${bareos_pid}/io"
)
while [ $(date +%s) -le ${time_out} ]; do
  sleep 1
  if sed '
    s/^read_bytes: //
    t
    d
  ' "/proc/${bareos_pid}/io" \
  | grep -qvxF "${was}"; then
    >&2 echo 'bareos-fd is reading'
    exit 1
  fi
done
>&2 echo 'bareos-fd is not reading'