#!/bin/sh

# chg-rait
#
# This assumes we have rait-striped drives in several
# other amanda changer configs.
#
# so we have a changerfile that lists other changers and
# changer files.
#   nchangers=3
#   tpchanger_1="chg-mtx"
#   changerdev_1="/dev/mtx1"
#   changerfile_1="/some/file1"
#   tapedev_1="/some/dev"
#   tpchanger_2="chg-mtx"
#   changerdev_2="/dev/mtx2"
#   changerfile_2="/some/file2"
#   tapedev_2="/some/dev"
#   tpchanger_3="chg-mtx"
#   changerdev_3="/dev/mtx3"
#   changerfile_3="/some/file3"
#   tapedev_3="/some/dev"
#
# the tapedev_n entries are only needed if the changer script in question
# uses tapedev.
#

#
# debugging...
#
if [ -d "@AMANDA_DBGDIR@" ]; then
	DBGFILE=@AMANDA_DBGDIR@/rait-changer.debug
	KIDDEBUG=@AMANDA_DBGDIR@/changer.debug
	WORK=@AMANDA_DBGDIR@/chgwork$$
else
	DBGFILE=/dev/null
	KIDDEBUG=/dev/null
	WORK=/tmp/chgwork$$
fi

exec 2>$DBGFILE
echo "args: $0 $*" >&2
set -x 

#
# the usual config fun
#
prefix=@prefix@
exec_prefix=@exec_prefix@
sbindir=@sbindir@
libexecdir=@libexecdir@

USE_VERSION_SUFFIXES="@USE_VERSION_SUFFIXES@"
if test "$USE_VERSION_SUFFIXES" = "yes"; then
        SUF="-@VERSION@";
else
	SUF=
fi
getconf=$sbindir/amgetconf$SUF


PATH=$sbindir:$libexecdir:/usr/bin:/bin:/usr/sbin:/sbin:/usr/ucb
export PATH 

changerfile=`$getconf changerfile`
. $changerfile

#
# get config items that other changers use to put in our
# fake amanda.conf files.
#
org=`$getconf ORG`
mailto=`$getconf mailto`

#
# make a working directory (with amanda.conf) for each changer, and start the
# changer script in background for each one
#

i=1
while [ $i -le $nchangers ]
do
   eval tpchanger=\$tpchanger_$i
   eval changerdev=\$changerdev_$i
   eval changerfile=\$changerfile_$i
   eval tapedev=\$tapedev_$i

   mkdir -p $WORK/$i
   cd $WORK/$i

   cat >> amanda.conf <<EOF
org     	"$ORG"
mailto  	"$mailto"
tpchanger 	"$tpchanger"
changerdev 	"$changerdev"
changerfile 	"$changerfile"
tapedev 	"$tapedev"

define tapetype EXABYTE {
    comment "default tapetype"
    length 4200 mbytes
    filemark 48 kbytes
    speed 474 kbytes			
}
EOF

    (
	$tpchanger "$@"
	echo "$?"> exitcode 
    )  > stdout 2>stderr &

   i=`expr $i + 1`
done

wait

#
# once they've all finished, collect up the results
#

myexit=0
myslot=-1
mymax=65536
myflag=1
mydev=""
mysep="{"

case x$1 in
x-slot|x-reseti|x-eject|x-search|x-label)

    #
    # read slot number and device from each
    # slot numbers must match(?!), and is our resulting slot number
    # resulting device is {dev1,dev2,...} from each one
    #
    i=1
    while [ $i -le $nchangers ]
    do
	read exitcode < $WORK/$i/exitcode
	read n dev < $WORK/$i/stdout
	echo -------------- >&2
        cat $WORK/$i/stderr >&2
	cat $KIDDEBUG >&2
	echo -------------- >&2

	if [ "$exitcode" != 0 ]
	then
	    myexit=$exitcode
	fi
	if [ $myslot = -1 ]
	then
	    myslot=$n
	fi
	if [ $n != $myslot ]
	then
	     # synch error!
	    myexit=1
	    echo "stackers are out of synch, issue a reset" >&2
	fi
	mydev="$mydev$mysep$dev"
	mysep=","

	i=`expr $i + 1`
    done
    mydev="rait:$mydev}"
    echo $myslot $mydev
    ;;
x-info)
    #
    # read info from each
    # slot numbers must match(?!), and is our resulting slot number
    # minimum max slots is our resulting max slots
    # if any can't go backwards, the aggregate can't either
    #
    i=1
    while [ $i -le $nchangers ]
    do
	read exitcode < $WORK/$i/exitcode
	read n max flag < $WORK/$i/stdout
	echo -------------- >&2
        cat $WORK/$i/stderr >&2
	cat $KIDDEBUG >&2
	echo -------------- >&2

	if [ "$exitcode" != 0 ]
	then
	     myexit=$exitcode
	fi
	if [ $myslot = -1 ]
	then
	    myslot=$n
	fi
	if [ $n != $myslot ]
	then
	     # synch error!
	    myexit=1
	    echo "stackers are out of synch, issue a -reset" >&2
	fi
	if [ $max -lt $mymax ]
	then
	    mymax=$max
	fi
	if [ $flag = 0 ]
	then
	    myflag=0
	fi
	i=`expr $i + 1`
    done
    echo $myslot $mymax $myflag

esac

#
# clean up work directories
#
rm -rf $WORK

exit $myexit