#!/bin/sh
#
# Bacula interface to mtx autoloader
# (By Lars Koeller, lars+bacula@koellers.net)
#
#  If you set in your Device resource
#
#  Changer Command = "path-to-this-script/chio-bacula %c %o %S %a"
#    you will have the following input to this script:
#
#  chio-bacula "changer-device" "command" "slot" "archive-device"
#
#  for example:
#
#  chio-bacula /dev/sg0 load 1 /dev/nst0 (on a FreeBSD system)
#
#  If you need to to an offline, refer to the drive as $4
#    e.g.   mt -f $f offline
#
#  Many changers need an offline after the unload. Also many
#   changers need a sleep 60 after the mtx load.
#
#  N.B. If you change the script, take care to return either
#   the mtx exit code or a 0. If the script exits with a non-zero
#   exit code, Bacula will assume the request failed.
#

# This simulates a barcode reader in the changer.
# The labels of the virtual barcode reader are located in the BARCODE_FILE
SIMULATE_BARCODE=true
BARCODE_FILE=/usr/local/etc/bacula-barcodes

me=$(basename $0)

# Debug
echo "$me $@" > /dev/console

if [ -z "$1" ] ; then
    usage;
fi

if [ -z "$2" ] ; then
    usage;
fi

MTX=/bin/chio
CHANGER=$1
COMMAND=$2
if [ ! -z "$3" ]; then
    SLOT=$3
fi
if [ ! -z "$4" ]; then
    TAPE=$4
else
    TAPE=/dev/nrsa2
fi

# Time to wait for loading
SLEEP=20
# What drive of the autochanger should be used primary
# At the moment bacula (1.31a) could not deal with more drives
DRIVE=1

usage()
{
  echo ""
  echo "The $me script for bacula"
  echo "--------------------------------------"
  echo ""
  echo "usage: $me <changer-device> <command> [slot] [devicename of tapedrive]"
  echo ""
  echo "Valid commands:"
  echo ""
  echo "unload          Unloads a tape into the slot"
  echo "                from where it was loaded."
  echo "load <slot>     Loads a tape from the slot <slot>"
  echo "                (slot-base is calculated to 1 as first slot)"
  echo "list            Lists full storage slots"
  echo "loaded          Gives slot from where the tape was loaded."
  echo "                0 means the tape drive is empty."
  echo "slots           Gives Number of available slots."
  echo ""
  echo "Example:"
  echo "  mtx-changer /dev/changer load 1   loads a tape from slot 1"
  echo ""
  exit 2
}


case ${COMMAND} in
    unload)
        # enable the following line if you need to eject the cartridge
        #mt -f ${TAPE} off
        #sleep 2
        ${MTX} -f ${CHANGER} return drive ${DRIVE}
        ;;

    load)
        ${MTX} -f ${CHANGER} move slot $((${SLOT}-1)) drive ${DRIVE}
        rtn=$?
        # Increase the sleep time if you have a slow device
        sleep $SLEEP
        exit $rtn
        ;;

    list)
        if [ "${SIMULATE_BARCODE}" = "true" ]; then
            if [ -f "$BARCODE_FILE" ]; then
                cat $BARCODE_FILE | grep -v "^#"
                exit 0
            else
                echo "Barcode file $BARCODE_FILE missing ... exiting!"
                exit 1
            fi
        else
            ${MTX} -f ${CHANGER} status | grep "^slot .*: .*FULL>" | awk '{print $2}' | awk -F: '{print $1+1" "}' | tr -d "[\r\n]"
        fi
      ;;

    loaded)
        # echo "Request loaded"
        ${MTX} -f ${CHANGER} status -S > /tmp/mtx.$$
        rtn=$?
        cat /tmp/mtx.$$ | grep "^drive ${DRIVE}: <FULL>" | awk '{print $6+1}' | tr -d ">"
        cat /tmp/mtx.$$ | grep "^drive ${DRIVE}:  source: <>" | awk "{print 0}"
        rm -f /tmp/mtx.$$
        exit $rtn
        ;;

    slots)
        # echo "Request slots"
        ${MTX} -f ${CHANGER} status | grep "^slot " | tail -1 | awk '{print $2+1}' | tr -d ":"
      ;;

    *)
        usage
      ;;
esac