#! /bin/ksh

if [ "$3" == "" ] ; then
    echo ""
    echo "Syntax: $0 <area> <newarea> <newbase vnum>"
    echo ""
    exit 1
fi

if [ ! -r "$1" ] ; then
    echo ""
    echo "Can't read input area \"$1\""
    echo ""
    exit 1
fi

if [ -f "$2" ] ; then
    echo ""
    echo "Destination name exits! Cannot continue"
    echo ""
    exit 1
fi

infile=$1
outfile=$2
tempfile=${HOME}/rename`date +%Y%m%d%H%M%S`

vnumrange=`grep "^V" $infile`
origbase=`echo $vnumrange | awk '{print $2}'`
origtop=`echo $vnumrange | awk '{print $3}'`
origtopp=$((origtop+1))

offset=$(($3-origbase))

echo ""
echo "Reading: $infile"
echo "Writing: $outfile"
echo "tempfile: $tempfile"
echo "vnums  : $origbase - $origtop"
echo "offset : $offset"
echo ""

vnum=$origbase

cp -f $infile $tempfile

while [ "$vnum" -lt "$origtopp" ]; do
    changeto=$((vnum+offset))
    echo "converting: $vnum to $changeto"

    count=1
    while [ "$count" -lt "3" ]; do

        grep $vnum $tempfile > /dev/null
        if [ "$?" != "0" ] ; then
            break;
        fi

        sed \
            -e "s/\b$vnum\b/$changeto/" \
            $tempfile > $outfile
        mv -f $outfile $tempfile

	count=$((count+1))
    done
    
    vnum=$((vnum+1))
done

mv $tempfile $outfile

echo "done"